M94 Extruded Primers

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Aaron posted this 23 March 2024

I have two IDENTICAL Cimarron Arms (Uberti) Model 94 rifles chambered in .38-55 Winchester. After filing a radius at the 6 o’clock position on the breech face, both rifles now feed ammunition without a hitch. While shooting the second rifle last week, I noticed that it simply would not open the action after the shot. It was jammed up tight.

The load is a very moderate load with Starline 2.085” (short) brass. The propellant is 28gr of IMR-3031, a Hunter Supply 260gr FP bullet, and lit off with a Winchester Large Rifle primer. This was the third such load tested in the rifle with the same result. Propellants varied on previous loads with Buffalo Rifle, RL7, A2520, and another with a propellant I can’t recall at this writing.

ALL of the loads resulted in a jammed-up action which could not be opened with normal force on the lever. To get the fired cartridge out of the chamber I had to cock the hammer and drop the hammer on the fired case. The lever could then be operated in the usual manner and the fired case extracted. Once ejected, the backed-out primers became visible. The primers are extruding at least .015” and may have been seated a tad deeper with the firing pin strike on the fired case.

A focused internet search on M94 backed out primers seemed to yield a consensus of a Headspace issue which was(is) endemic to the M94 family of rifles. Of course, there were dissenting opinions which ran the full gambit from Alien interference to dirty chambers. Rest assured, my chamber is “normal” and operating pressures are within industry standards.

I am believing the headspace argument is valid based on a few things:

  • Winchester made thicker locking bolts to accommodate headspace issues in decades past. A .005” thicker locking bolt was normal and can still be purchased on various sites.
  • When my bolt goes into battery, I can use my thumbnail to push it forward just enough to be visible. The locking bolt also appears to rise just a little bit too. That could be my imagination, but it does seem to rise a bit and hold the bolt forward.
  • The Starline .38-55 brass I have is measuring .056” rims and not the .063” as called for by SAAMI. Not as thick as they could be, but not by much.
  • My measurement for headspace is .071” or 1 thou greater than the SAAMI spec.

One thing is certain, the SAME cartridges fired in the first rifle DO NOT have extruded primers. The bolt on the first rifle can not be manipulated forward on that rifle either. Two identical rifles. One extrudes primers, one does not.

I have to say the headspace argument is correct although I have to admit, I do NOT see how excessive headspace will allow a primer to extrude. That case is going rearward when fired and should seat that primer flush, if anything, with the case head. I simply can’t envision it in my feeble little brain.

I may order a “Field” gauge to see if the action will close on it, but still have a few comparative tests to make before I spend even more money. I’ll try the 2.125” brass to see if it also extrudes primers. It could be the brass primer pocket with this lot of Winchester primers is incompatible. Like I say, a few more tests are in order.

Do any of you who shoot a M94 and have experienced extruded primers have any input here?

Rifle-1, Extruded Primers

Rifle-2, Normal Primers, Same Load

 

With rifle in hand, I confidently go forth into the darkness.

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Bill*B posted this 23 March 2024

I've been told that light loads can push the primer out like a piston and push the case forward.  Pressure then develops enough for the forward part of the case to grab onto the chamber wall, but too little to push the case head back again.  If load was hotter, developing pressure would rise high enough to push the case head back, and reseat the primer. Should this be your situation, cure would be to load hotter. Just a thought.  Bill

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Aaron posted this 23 March 2024

Thanks Bill. This isn't a light load issue. Boiler pressure is normal albeit on the low side. I will however work up a stiffer load to see what happens in Rifle-1.

 

With rifle in hand, I confidently go forth into the darkness.

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pat i. posted this 23 March 2024

I don't know how well this will work with a lever gun and a rimmed case but have you tried seating the bullet out a little longer so there's a little resistance when closing the bolt and slight land marks on the bullet. It might keep the case head tight enough on the bolt face to stop the primers backing out. How does the gun shoot?

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MP1886 posted this 23 March 2024

Aaron you said "I have to say the headspace argument is correct although I have to admit, I do NOT see how excessive headspace will allow a primer to extrude. That case is going rearward when fired and should seat that primer flush, if anything, with the case head. I simply can’t envision it in my feeble little brain."

First let me tell you an expriment that Ackley did.  He removed the locking lug from a Model 94 Winchester in 30-30.  The he loades some normal pressure cartridges. He cleaned all oil, lube, wax off the cartridges. He did the same to the chamber.  He fired the rifle in a fixture and it didn't blow the action open.  The reason is the case at the moment of firing obturates to the chamber until the pressure is gone.  Ackley wanted to prove that and he did.   I feel your rifle has a little excess headspace and the case is obturating to the chamber and letting the primer blow out some.  Try this, take your same load, but lube your case up, the entire case. Don't need to touch the bullet. Then fire it and tell us if the primer is protruding. 

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Aaron posted this 23 March 2024

I don't know how well this will work with a lever gun and a rimmed case but have you tried seating the bullet out a little longer so there's a little resistance when closing the bolt and slight land marks on the bullet. It might keep the case head tight enough on the bolt face to stop the primers backing out. How does the gun shoot?

I'll add that to the list of "try this" stuff to see if I can stop the primers backing out on this rifle. OAL is a very serious issue with the M94 in 38-55 Win. Picture stuffing a cigar back into a cigar tube held horizontally. Feed angle is critical when stuffing a fat long bullet into a narrow chamber. The angle of attack is critical. Even the Starline 2.125" cases can be difficult. The 2.085" cases are better but extending the bullets out aggravate the matter substantially. The M94 in 30-30 is a no-brainer. It shoves a thin bullet into a large hole. Easy peasy there.

There is something else going on here and I am determined to find the issue. I think step one is to bring the boiler pressure up near max and see what happens.

 

With rifle in hand, I confidently go forth into the darkness.

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Aaron posted this 23 March 2024

First let me tell you an expriment that Ackley did.  He removed the locking lug from a Model 94 Winchester in 30-30.  The he loades some normal pressure cartridges. He cleaned all oil, lube, wax off the cartridges. He did the same to the chamber.  He fired the rifle in a fixture and it didn't blow the action open.  The reason is the case at the moment of firing obturates to the chamber until the pressure is gone.  Ackley wanted to prove that and he did.  

Thank you for your suggestion. Note that Ackley did his experiment with a 30-30AI cartridge, not a 30-30. Both however are bottleneck cartridges and their obturation is quite different than a straight-wall cartridge like the 38-55. That sir, is apples to oranges, so to speak. Your point however is taken. One of my pending tests will be a BP cartridge whereby the bullet really gets a kick in the arse, and the cartridge obturates on a different pressure/time curve. We shall see.

 

 

With rifle in hand, I confidently go forth into the darkness.

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pat i. posted this 23 March 2024

OAL is a very serious issue with the M94 in 38-55 Win. Picture stuffing a cigar back into a cigar tube held horizontally. Feed angle is critical when stuffing a fat long bullet into a narrow chamber. The angle of attack is critical. Even the Starline 2.125" cases can be difficult. The 2.085" cases are better but extending the bullets out aggravate the matter substantially.

 

Good point. I didn't think of that.

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MP1886 posted this 23 March 2024

First let me tell you an expriment that Ackley did.  He removed the locking lug from a Model 94 Winchester in 30-30.  The he loades some normal pressure cartridges. He cleaned all oil, lube, wax off the cartridges. He did the same to the chamber.  He fired the rifle in a fixture and it didn't blow the action open.  The reason is the case at the moment of firing obturates to the chamber until the pressure is gone.  Ackley wanted to prove that and he did.  

Thank you for your suggestion. Note that Ackley did his experiment with a 30-30AI cartridge, not a 30-30. Both however are bottleneck cartridges and their obturation is quite different than a straight-wall cartridge like the 38-55. That sir, is apples to oranges, so to speak. Your point however is taken. One of my pending tests will be a BP cartridge whereby the bullet really gets a kick in the arse, and the cartridge obturates on a different pressure/time curve. We shall see.

 

It doesn't matter the shape of the cartridge. Gas pushes on all the areas of the entire case. The neck area of the case obturates to the chamber wall just as much as the the straight wall cases. 

I would appreciate if you did oil up a case, not slopping wet, just lube it up with your fingers and shoot it. This is safe by the way as you not shooting a maximum load. Let us know what happens.

This oiling of the case or graphiting it is a method to get the entire case to blow out. So of the science to this has to do why belted magnum cases are more likely to have a head separation because non experienced reloading are setting the shoulders back by sizing them and being the belt headspaces the cartridge, when it's fires the thinner parts of the body obturate to the chamber walls and the solid rearend of the case doesn't and gets pushed back against the breech face and stretches the brass between that solid head and the obturated rest of the case eventually causing a head separationg. 

Please give it shot. 

 

 

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Wilderness posted this 23 March 2024

Aaron - if the lockup is a headspace induced issue, you may be able to prove the point by rigging some cartridges with headspace circlips as per my recent post:

https://forum.castbulletassoc.org/thread/headspacing-30-30-and-other-rimmed-bottleneck-cases/

From the rim and chamber dimensions you describe, you are looking at about .015" of slop. This is exactly the issue I was addressing when describing a way of reducing this to zero with shoulder headspacing. Of course with .38-55 you do not have  the shoulder to fall back on, so all the circlips will do is prove the point. Unless of course you find it expedient to circlip all your ammo.

Material for the circlip will be electrical copper wire, or hobby shop brass wire. Think old electric motor windings or multi-strand cable. In the first instance you can try .015" wire, but you may lose some of that .015" on chamber bevel, if the bevel is all the way around the chamber. If necessary use heavier wire. Leave a gap in the circlip for the extractor, though with the smaller wire you might get away without it.

I have a nagging suspicion that you may need to look further to solve the lockup issue, e.g. by swapping or polishing parts, but you can at least eliminate the headspace possibility first.

The image shows circlips that have been flattened because the wire was too thick, but you may not have to do that.

Incidentally, you can also run a headspace measurement without gauges by partially seating a primer in an empty case, preferably new, closing the action on the case, then afterwards measuring primer protrusion.

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Aaron posted this 24 March 2024

I read that post and am amazed at the ingenuity our members show in problem solving skills. I have a few things to try first before the case setback with a c-clip. Thanks for the reply and the reminder that this may prove concept.

 

With rifle in hand, I confidently go forth into the darkness.

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Clod Hopper posted this 24 March 2024

You do have excess headspace aggravated by the thin rims on your cases.  You should not be able to move the bolt like that. That sounds excessive to me.   A heavier load would cause the extruded primers to be fully seated after firing.  This does not solve the problem though.  At full power the brass moves forward, the pressure pushes the primer back since there is nothing to stop.  The brass case clings to the chamber walls for a miilsecond and only after pressure gets higher does it slam back in the breech block.  This reseats the primer, but you may get a flattened primer that looks like excess pressure.  You could only partially size the cases so that the case headspaces on the shoulder like a .30-.06.  That may work for your currrent load.  The .38-55 headspaces on the rim.  You could also find some thicker brass, maybe some .30-30, or .375 Winchester.  If it were my rifle, I might send it back.  At least have a gunsmith look at it.

Dale M. Lock

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Aaron posted this 24 March 2024

That feed issue was corrected on both rifles by filing a radius on the breech face like actual Winchester rifles have in their 38-55 rifles. The first rifle would not chamber a cartridge at all. Can’t believe it made it on the boat like that.

With rifle in hand, I confidently go forth into the darkness.

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pat i. posted this 24 March 2024

I dug out some WW once fired 38-55 brass if you want to try 10 of them. The rim is .055- .058 thick so you might not see any difference from what youre using now but the offer's there. The one I measured was 2.075 long.

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Aaron posted this 24 March 2024

That is a very kind offer. Let me putz with some other options first.

With rifle in hand, I confidently go forth into the darkness.

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pat i. posted this 24 March 2024

No sweat but the offer's there.

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Wilderness posted this 24 March 2024

 

MP1886

These big blocks of italicised text are difficult to untangle.

With the best possible intentions, and with a background including editing, I can offer some suggestions. Having opened the gate, I will of course expect some of the same in return.

The first suggestion is to reduce the quote to just that part of it to which you are replying. The unwanted parts can be edited out before you start on your own reply.

The next suggestion is to separate the italicised quote from the text of the reply by removing the italics on the reply. Now we can see who said what.

The last suggestion concerns sentence length. Even if you start with long sentences, go back over your work and cut them up into shorter ones. Anything over about 20 or 30 words needs a second look. That said, I can see that my post ended with a long sentence. This just goes to show that sentence length requires discipline.

 

 

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Ken Campbell Iowa posted this 24 March 2024

looks like too much bolt-to-head clearance ....   " headspace " for our purpose ... ...

i would establish this first so that you can move directly to the next decisions.

a decent kitchen table crutch to check this is to cut little squares from a business card and use fast dry fingernail polish to glue them on the back of a case or cartridge ...  these will usually mike from 3 to 5 thousandths each.   

if you reload cases you really need not over 0.004 clearance  ...  the brass is going to be stretching when you fire it ... as described above the brass is shoved forward then it sticks at the front  when fired and at some pressure the back of the case is stretched back into the bolt.  at some less pressure the brass is not stretched but the primer is blown out the back a little to hit the bolt.

at low cast loads some grease the case and avoid stretching ...  at high pressures this crutch might peen the rifle parts eventually ... 

***************************

if you dont reload you can grit your teeth and get by with 0.008 or 0.010 head clearance ...  probably wont seperate new factory brass but just not a good feeling thing to do.

above 0.010 static head clearance you really need to tighten that clearance.,  for one thing a lever action rear locker metal is going to stretch a little more to add to the case stretch.

**************

i am not a lever action fixer guy, but the cheapest simple fix might be to braze a little metal to the locking bar and then file and lap back to a snug lockup ...  

enjoying this thread and hope this helps.

ken

 

 

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Premod70 posted this 25 March 2024

The primer protrusion is excessive headspace when seen on a rimmed case and no work around will safely solve the problem; send the rifle back.

Forrest Gump is my smarter brother.

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MP1886 posted this 25 March 2024

looks like too much bolt-to-head clearance ....   " headspace " for our purpose ... ...

i would establish this first so that you can move directly to the next decisions.

a decent kitchen table crutch to check this is to cut little squares from a business card and use fast dry fingernail polish to glue them on the back of a case or cartridge ...  these will usually mike from 3 to 5 thousandths each.   

if you reload cases you really need not over 0.004 clearance  ...  the brass is going to be stretching when you fire it ... as described above the brass is shoved forward then it sticks at the front  when fired and at some pressure the back of the case is stretched back into the bolt.  at some less pressure the brass is not stretched but the primer is blown out the back a little to hit the bolt.

at low cast loads some grease the case and avoid stretching ...  at high pressures this crutch might peen the rifle parts eventually ... 

***************************

if you dont reload you can grit your teeth and get by with 0.008 or 0.010 head clearance ...  probably wont seperate new factory brass but just not a good feeling thing to do.

above 0.010 static head clearance you really need to tighten that clearance.,  for one thing a lever action rear locker metal is going to stretch a little more to add to the case stretch.

**************

i am not a lever action fixer guy, but the cheapest simple fix might be to braze a little metal to the locking bar and then file and lap back to a snug lockup ...  

enjoying this thread and hope this helps.

ken

 Thanks for this post Ken, it's what I've been saying all along. My test was the oiled case.  If when fired the primer is flush, then the problems it excess headspace. Leaving little of the case lube on the case or lightly oiling them will solve the problem too as then the case will be driven back instead of obturate and stretching. Okay for light/medium loads, but eventually put more strain on the bolt lock up. 

 

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Rich/WIS posted this 25 March 2024

Sounds like the primer is protruding enough to bind against the bolt face.  When you drop the hammer again you are moving the primer forward enough to release the pressure on the bolt face and it opens.  I'd call Cimarron/Uberti and see what they say, maybe send it back with several fired cases so they can see the problem.  Hopefully they have good customer support.

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MarkinEllensburg posted this 25 March 2024

MP1886

These big blocks of italicised text are difficult to untangle.

With the best possible intentions, and with a background including editing, I can offer some suggestions. Having opened the gate, I will of course expect some of the same in return.

The first suggestion is to reduce the quote to just that part of it to which you are replying. The unwanted parts can be edited out before you start on your own reply.

The next suggestion is to separate the italicised quote from the text of the reply by removing the italics on the reply. Now we can see who said what.

Edit: You may need to do this by posting THEN editing.

The last suggestion concerns sentence length. Even if you start with long sentences, go back over your work and cut them up into shorter ones. Anything over about 20 or 30 words needs a second look. That said, I can see that my post ended with a long sentence. This just goes to show that sentence length requires discipline.

 It is really just as simple as un-clicking the " button. If only folks would just learn this little "feature" of the forum and how it works. Poorly designed, but it works.

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mashburn posted this 25 March 2024

Hello Aron,

Everything that you mention is proving that you have excessive headspace. Did you buy these two rifles new? I have used the headspace checking method that Ken mentions also, and it works. Another method that I have used to check head space without gauges, is to take a sized case and partially seat a primer, by partially seat, I mean leave part of the primer sticking out of the face of the cartridge head. Insert this cartridge in the chamber and close the bolt and the amount of primer that does not seat into the cartridge head is your amount of head space. I do this with bolt action rifles which have a degree of camming power, which helps seat the primer. Even though your lever action lacks this camming ability, you should be able to seat the primer with the lever.

The looseness that you mention about the locking lugs is not normal by any means. I hope you get your problem solved. Such happenings do not entice a person to be a happy camper. 

Mashburn

David a. Cogburn

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Premod70 posted this 25 March 2024

Add the two clearances for the rim and the chamber and you will come up with excessive headspace, SAAMI specs or not. The protruding primers are an obvious problem that should be corrected before any firing of the rifle. As I said before send the rifle back, shooting low pressure loads can just as dangerous as the high pressure and in this case both are equally so.

Forrest Gump is my smarter brother.

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MP1886 posted this 25 March 2024

MP1886

These big blocks of italicised text are difficult to untangle.

With the best possible intentions, and with a background including editing, I can offer some suggestions. Having opened the gate, I will of course expect some of the same in return.

 

Thank you for the tip, I'm trying it out now and much better as you said.  Again thanks for the tip.  Tony

 

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Aaron posted this 25 March 2024

Update on this issue.

I made 4 rounds up with the same load as the indicated load in the OP except I used Remington 9 1/2 primers. I fired two in Rifle-1. No primer extrusion (as expected). I fired two rounds in Rifle-2, which I have named "The Extruder" and guess what? No primer extrusion. Hmmm. There where what appeared to be light primer strikes on the two cases however.

I then fired an altogether different load with H4895 and S&B primers. No extrusion there either. Scratching my head now. Those cases are the four on the left in the image below. It seems that the Winchester LR primers I am using with this brass are somehow causing grief. It may be the +/- specs on the components causing me some problems whereas I am seeing both brass and primers at the max (or minimum) spec combined to cause some extrusions.

I have ordered a "No-Go" gauge to definitively test this bolt with. I will stop chasing my tail and see what the gauges tell me. I'll keep you all posted. For now, I will stop using the Winchester Large Rifle primers of this lot#.

Frustrated

 

With rifle in hand, I confidently go forth into the darkness.

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MP1886 posted this 25 March 2024

Aaron I can understand your frustration.  Something screwy certainly is going on. Right now it's a real head scratcher.  Might try one or two with the original load including the primers you used to see if it does it again. Thanks for reporting back.

 

Tony

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Ken Campbell Iowa posted this 26 March 2024

 ... i think someone in the band is playing a plastic flute ...

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Sevenfan posted this 29 March 2024

 It is really just as simple as un-clicking the " button. If only folks would just learn this little "feature" of the forum and how it works. Poorly designed, but it works.

Another way to do it is when quoting someone's post, click on the arrows icon in the text options bar, "< >", this opens a source code window. There you can snip anything you don't want to quote by deleting it like I did above. Here's what it looks like with an added space between the arrows to illustrate...

< blockquote >It is really just as simple as un-clicking the " button. If only folks would just learn this little "feature" of the forum and how it works. Poorly designed, but it works.< /blockquote >

As long as the text you wish to quote is included between, < blockquote > and < /blockquote > tags (without the extra space I added between the arrows) you can delete the rest and it will show in your reply by simply starting your comments after the last >. wink

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Aaron posted this 29 March 2024

There is good news and there is not so good news to report. The No-Go Gauge arrived today from Pacific Tool and Gauge in Oregon. Immediately noticeable was the thicker rim on the gauge. I mean noticeable to the eye. I haven't measured it yet but I did remove the extractor and the ejector from the M94 bolt. I reassembled the action and guess what? The bolt will not close on the No-Go Gauge. Headspace in this rifle is not the root cause of these extruded primers.

I believe there are several factors in play, interacting with each other, allowing these primers to extrude. The batch of Starline brass may be at the large end for primer pocket diameter as well as the thinner end of rim thickness allowable tolerance. The batch of Winchester primers may be on the small end of the tolerable allowance. Whatever the cause(s) for extrusion, it's not the guns headspace.

At least I have no reason to send the rifle off for analysis and correction. This has certainly been an exercise in options, analysis, and theory. My takeaway is to use other primers in this brass, and never assume something is causative without proper analysis tools. I was hesitant to spend the money for a single-use tool, but in this case, it has saved money and some embarrassment with Cimarron Arms/Uberti.

Thanks to all of you for your excellent suggestions and help with this issue. What a wonderful bunch of folks!

 

 

With rifle in hand, I confidently go forth into the darkness.

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MP1886 posted this 29 March 2024

Aaron I think the culprit in your case is the Starline brass.  Starline brass, although usually good brass, is not the Holy Grail of brass.  The gauge that will tell you if you have excess headspace is the Field gauge. If your bolt closes on a Field gauge you indeed have excess headspace. A Go gauge is the mininum headspace and the No gauge is the maximum headspace. That's the plus/minus that SAAMI sets.  I think your rifle, as compared to the one you don't have trouble with, is at the maximum allowable headspace set by SAAMI. If you had a really good lathe you could cut precise coins and carefully use the as headspace measureing tools. What would be nice about that is you could have an actually micrometer measurement of the headspace between the two rifle. You have used the Winchester primers in the other good rifle with no problems right?  If so I don't believe the primers are the problem. Leaning towards the Starline brass.  I might give Starline a call and explain to them your problem and I'll bet they want a few cases back. 

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Aaron posted this 29 March 2024

The gauge that will tell you if you have excess headspace is the Field gauge. If your bolt closes on a Field gauge you indeed have excess headspace.

Actually, the gauge that tells you if you have excessive headspace is the No-Go Gauge, The No-Go Gauge is the Maximum allowable headspace for that cartridge in that firearm. The Field Gauge allows slightly more headspace BEYOND the allowable maximum determined by the No-Go Gauge and is used by the military armorer to allow a firearm with excess headspace, but not beyond the Field Gauge spacing, to be used by REMFs and not the combat FOB. Guns that pass the Field Gauge are probably safe enough for prison guards, cooks, intel weenies, and other REMFs to use without case separation. A civilian gunsmith who states that the gun does not have excessive headspace by using a Field Gauge, whereby a customer is injured when shooting that firearm, will be a gunsmith no longer after the attorney's are through with him/her.

The assumption that a Field Gauge indicates allowable headspace is a myth propagated by individuals who have not attended a quality armorers course or quality civil gunsmith course. Use of a Field Gauge by an armorer is after the No-Go Gauge indicates excessive headspace. The Field Gauge is simply used to determine how bad the excess headspace is.

I think I will work with the variables I have and be sure to not utilize the components with this mixture. Changing the primers definitely helped. I'll leave Starline alone since 38-55 brass is not a top priority with them.

I wish I had a lathe and the knowledge to use one. Had I taken shop class instead of Calculus, I would be having more fun!

Shoot Safe!

 

With rifle in hand, I confidently go forth into the darkness.

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pat i. posted this 29 March 2024

With my low pressure pb 06 loads I get some primer protrusion using Winchester primers. Not so much with Federal or Remington primers. The WW are a lot easier to seat too. Don't know if it's diameter or just harder cups but that's my experience and maybe why with the Lee hand primer tool they tell you not to use Federal primers. I just measured a Fed, WW, and Rem lr primer. The Fed and Rem are .210 and the WW .2095. I don't know if half a thousandth would make a big difference but the WW are a lot easier to seat and I get more of the primers backing out.

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Wilderness posted this 29 March 2024

I just remembered another way I checked HS on a M94 - with the bolt closed on an empty, but the locking lug not yet home, put a (narrow) feeler gauge between the back of the bolt and the locking lug. Continue to close. Repeat until you find the right thickness.

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Aaron posted this 29 March 2024

The WW are a lot easier to seat too. Don't know if it's diameter or just harder cups but that's my experience and maybe why with the Lee hand primer tool they tell you not to use Federal primers.

Absolutely agree. WW primers seat easily. CCI are the worst and my thumb gets squashed when using the Lee Auto Prime hand tool. I ended up getting a RCBS Automatic Priming Tool. Glad I did. My thumbs are now normal size and this rascal seats any primer easily with its mechanical advantage. The Lee hand prime tool is the easiest to use but man, it does a number on your thumbs.

 

With rifle in hand, I confidently go forth into the darkness.

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MP1886 posted this 29 March 2024

Aaron essentially what you said about the field gauge is exactly what I said, except I said it a different way. There's another gauge that I bet most of you don't know about and it's called a "manufacturing gauge".  

The field gauge is the militarys way of basically allowing a rifle out in the field that shouldn't be in my opinion.

 

Used Winchester primers by the millions, never had a problem with them. My most offending primers have been CCI. 

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pat i. posted this 29 March 2024

There's another gauge that I bet most of you don't know about and it's called a "manufacturing gauge.

Pray tell what's a "manufacturing guage? Don't be man of 1000 secrets, it gets annoying. We all love learning new things. I've probably chambered 20 barrels for my own use and never heard of one. And a search on the internet and reamer makers turned up nothing.

Aaron I couldn't agree more about the Lee tool. Use that thing to seat Fed primers for a couple of months and you'd be unbeatable in a thumb wrestling contest. I use my Sinclair hand primer when playing with those hard to seat primers. It does the job with ease.

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admiral posted this 29 March 2024

Right now over on the Accurate Shooter forum some people are having issues with Winchester LR primers. Mainly gas leakage around the primer edge etching the bolt face. They had this issue about 10 years ago with some lots and were taking them back and issuing refund checks. After having it happen to me Winchester paid to have my bolt face bushed. I returned a case (5000) of LR primers to them for a refund. It was like $135, those were the days, lol. Winchester did decrease their primer dimensions, we're talking a few 10,000's, for easier function in progressive reloading presses. This was reported in Handloader magazine a decade ago by, I think, John Barsness. I haven't shot millions of Winchester primers as MP1886 has but have shot hundreds of thousands of Winchester LR primers since the early '80's and never had any issues with the older style silver colored primers. I don't like the brass colored Win LR primers and will not use them anymore.

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Aaron posted this 29 March 2024

Right now over on the Accurate Shooter forum some people are having issues with Winchester LR primers. Mainly gas leakage around the primer edge etching the bolt face.

And sure as heck, a few months ago I was getting gas blow-by on my WW primers. It was the 7.62x54R. I KNOW the pressure wasn't the culprit and was scratching my tiny little head about it. Good to know. Thanks for the post Admiral

 

 

With rifle in hand, I confidently go forth into the darkness.

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Premod70 posted this 30 March 2024

Hey Aaron, curious to know the thickness of the no-go gauge.

Forrest Gump is my smarter brother.

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Premod70 posted this 30 March 2024

Hey Aaron, curious to know the rim thickness of the no-go gauge.

Forrest Gump is my smarter brother.

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Aaron posted this 30 March 2024

Hey Aaron, curious to know the rim thickness of the no-go gauge.

I'll get that for you tomorrow. I have buttoned up the shop for the evening. Remind me if I forget to post that for you.

 

With rifle in hand, I confidently go forth into the darkness.

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MP1886 posted this 30 March 2024

All the Winchester primers I shot were the silver ones also.  Then I switched brands because of costs. 

Aaron I'm sure you mean you had blow by with your WW primers in a 7.62x54R cartridge instead of 7.72. Hey just jabbing you, that's all.  Mabye you do have lousy newer WW primers, but you didn't answer why your other rifle firing the same ammo didn't have any problems. 

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Aaron posted this 30 March 2024

Mabye you do have lousy newer WW primers, but you didn't answer why your other rifle firing the same ammo didn't have any problems. 

We may never know. Different chamber I suppose. 

With rifle in hand, I confidently go forth into the darkness.

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MarkinEllensburg posted this 30 March 2024

Right now over on the Accurate Shooter forum some people are having issues with Winchester LR primers. Mainly gas leakage around the primer edge etching the bolt face.

How interesting. When I was in my 20s and buying rifles my Dad mentioned that you can tell from a bolt face how much a rilfle has been shot by the ring around the firing pin. I am guessing years later that there likely is a small amount of gas leakage past primers even under ideal specs for that to be an issue.

I am currently using Remington primers that are very hard to seat. I can't seem to reliably seat them below flush with my primer arm on my RCBS Rockchucker press. Lee's early hand prime works just fine though. Anyway last match I believ I was seeing gas leakage around some primers. I seriously wonder how many 1000's of rounds it takes for gas cutting of a boltface to be an issue.

I think what Aaron is seeing is a case of excessive headspace due to tolerance stacking. It seems he has found the solution by adjustment of components.

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MP1886 posted this 30 March 2024

When  you have constant leakage you get pitting in the ring you see. What you are seeing is friction wear and remember the primer is pushing back on the bolt face too.  The ring is the gap between the round corners of the primer and the round corner of the primer pocket mouth. That's why the you get the ring because that gap doesn't wear anything, if you understand what I mean. 

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Aaron posted this 30 March 2024

Mark….I like that term “tolerance stacking”. It seems that it is what is going on in Rifle-2 where its chamber, and all the other components, allow primer back-out. Rifle-1 must have a different chamber which is not contributory to the stacking phenomena.

 

 

 

With rifle in hand, I confidently go forth into the darkness.

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Aaron posted this 30 March 2024

Hey Aaron, curious to know the rim thickness of the no-go gauge.

It's .071" on the button. For the doubters out there, here are images of the measurements.

So, when I went to school .050" + .018" + .003" = .071"

 

With rifle in hand, I confidently go forth into the darkness.

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MP1886 posted this 30 March 2024

Aaron you know what the SAAMI drawing specs say?   The rim thickeness of the case min = .063 and max = .073, but the their measurement from the bolt/breech measurement (which is this case being a rimmed cartridge is the headspace) is min = .063 and max = .070. Hmmm that doesn't sound just right. You can look it up on SAAMI specs for center fire cartrdiges.  It's the same measurements for the 375 Winchester.   Confusing isn't it?

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Aaron posted this 30 March 2024

Aaron you know what the SAAMI drawing specs say?   The rim thickeness of the case min = .063 and max = .073, but the their measurement from the bolt/breech measurement (which is this case being a rimmed cartridge is the headspace) is min = .063 and max = .070. Hmmm that doesn't sound just right. You can look it up on SAAMI specs for center fire cartrdiges.  It's the same measurements for the 375 Winchester.   Confusing isn't it?

No confusion whatsoever. The measurement (gauge) is a binary measurement tool. It will or it will not. Yes or No. A one or a zero. It does not display continuous data, it reports discreet data. If the gauge rim thickness was .070" (the max SAAMI tolerance for 38-55 headspace), and the bolt closed on the gauge, is the headspace actually at the maximum or over the maximum? With the gauge set to .071" and a bolt closure, one can say the headspace is OVER maximum. By how much is irrelevant at this point. We simply wish to know a discreet piece of data - is the headspace OVER maximum or not.

I think at this point, we are beating a dead mule. We should probably let this thread die off since we are way off topic now. I have stated my belief of the tolerance stacking theory for the extruded primers since going with another brand of primers cured the problem in Rifle-2, which was never a problem in Rifle-1 with its differing chamber.

Have a great day and shoot safe!

 

 

With rifle in hand, I confidently go forth into the darkness.

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pat i. posted this 30 March 2024

The rim thickeness of the case min = .063 and max = .073

Actually the case rim thickness spec is .063 - .010, in other words.053 to .063 so the cases are well within spec.

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Premod70 posted this 30 March 2024

Another point of curiosity is the remaining measurement not stated is the protrusion of the fired primer.

Forrest Gump is my smarter brother.

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Wilderness posted this 31 March 2024

Original post, third paragraph, .015".

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Premod70 posted this 31 March 2024

Thanks Wilderness, I looked three times and missed it every time. Time for my afternoon nap:-).

Forrest Gump is my smarter brother.

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