Headspacing .30-30 and other rimmed bottleneck cases

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  • Last Post 11 February 2024
Wilderness posted this 29 January 2024

Most discussions of case life in .30-30 or .303, or similar, stress the desirability of sizing the case to headspace on the shoulder, not the rim. This of course excludes straight cases like .38-55, .45-70 and the pistol cases. What follows relates to .30-30.

If the rifle has tight headspace the process starts with firing the cartridge. The shoulder blows forward to fit the chamber. Then adjust the FLS die (or neck die) so that it does not push back the new shoulder.

If the rifle has loose headspace, like my Savage 99, the process begins with a fired (or unfired) case that has not already been stretched. My .30-30 cases mostly start life as once fired donations.

My preferred method of blowing the shoulder forward is to make circlips out of copper wire . The circlips go around the groove forward of the rim, leaving a gap for the extractor.

 

 

 

 

 

Since the circlip has also to fill in the bevel on the back of the chamber, and is pushed into the groove around the case, the wire diameter will be rather more than the amount of headspace to be taken up. Find some wire that is just a bit too fat, then if necessary squash to the “just fit” thickness. I used my 7/8” press for this, putting the flat faced lower part of my Lyman priming tool on the bottom, and a piece of flat steel against the bottom of a loading die on top.

 

 

Fire the cartridge with circlip and you will have the shoulder in place with one shot, or maybe two. Shoot these cartridges as normal loads. You may be restricted to single loading. For my rifle I can position the top cartridge in the magazine to feed so the extractor finds the gap in the circlip.

The other method I have used is to open a .30-30 case up to .375 with a series of M Dies, then size back to .30-30 with the more forward shoulder. A good smear of anhydrous lanolin around the inside lip of the neck precludes neck splitting. The case shortens about .050” on the way to .375, and recovers about .025" going back to .30-30, net loss .025”.

Larry Gibson writes of doing something similar but with expansion to just .35”.

The last method is to seat the bullet out to engage the rifling with resistance. Disadvantages are unknown effect on ballistics and (in my case) a loaded cartridge too long to eject.

To know whether the shoulder is far enough out without trying every case in the rifle, you will need a gauge. It can be simple. I use a spare .354” bullet sizing die with punch removed. I place the case or cartridge nose first in the top of the die, so the shoulder engages the lip of the die, and measure the combined height of die and cartridge with vernier calipers. With my setup 3.100” is a gentle crush fit in the rifle. New Starline cases measure 3.035”. I understand that there is also a commercial product for this measurement.

 

 

 

 

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Larry Gibson posted this 07 February 2024

Wilderness stated right up front "Most discussions of case life in .30-30 or .303, or similar, stress the desirability of sizing the case to headspace on the shoulder, not the rim"

 

That has nothing to do with, nor does he mention anything about the rifle having "excessive headspace".  He is just referring to fire forming and then sizing the cases so they headspace on the shoulder and not the rim.  Many, including myself have been doing this for many years.

LMG

Concealment is not cover.........

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MP1886 posted this 08 February 2024

The picture of the copper ring ahead of the rim tells me the case is not supported as well as it would be in a properly headspaced firearm. No way that firearm will be safe no matter how much the case shoulder is pushed forward.
I'm going to clear that up for, he's merely using that ring as you call it to blow the shoulder forward so that he can then size the shoulder back to where he wants it.  The other posts explaing how to create a false shoulder such as expanding the neck up to 35 or 375 caliber and then sizing the shoulder to where you want it. Like I explained in the previous post it's not going to hurt anything and it's not unsafe. 

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Mal in au posted this 30 January 2024

Find the size of “0” ring that fills  the grouve ,much quicker than copper wire! Works a treat,have a LE 1 BSA .303 that was a little big on headspace now registers on the shoulder after the O ring treatment. Used normal cast loadings ,ie 22 gns (H 4227) au 2205  170 gn CBE Lino pill. Est. 1770 fps, also shoots J word full loads as well.     Cheers Mal in au.

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RicinYakima posted this 30 January 2024

I simple leave the Imperial Sizing Die wax on the case every time. Then neck size and reload and headspaced on the the shoulder. BUT it only works for cases dedicated to one rifle. 

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MP1886 posted this 07 February 2024

A rimmed cartridge headspaces on the rim, not the shoulder. Doing otherwise leaves the case unsupported at the most critical place in the chamber. The OP’s work around is not safe practice as well as any other attempt to correct headspace with the shoulder of a rimmed case having excess headspace.

 

Oh My! Where to begin.  Larry Gibson already addressed this and perhaps you missed what he posted. I'm going to put it in capital letters, not yelling at you, so that you can see it. THE OP DOES NOT HAVE AN EXCESS HEADSPACE PROBLEM!!!!!!! THATS DOES NOT!!!!!   He merely wants to be able to size his cases WITHOUT pushing the shoulder back any at all.  An analogy: It's like, but not exactly, want's to end up with a case fit in the chamber as though the case was neck sized only. 

 

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Bud Hyett posted this 07 February 2024

Cartridge and chamber drawings. The tolerances are in the lower right corner of the drawing. 

Farm boy from Illinois, living in the magical Pacific Northwest

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John Alexander posted this 29 January 2024

Very interesting,  

In the method of using a bullet seated out to engage the rifling, would seating the bullet backward maybe keep the overall length short enough to eject from your rifle?

John

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Wilderness posted this 29 January 2024

John - short answer yes. Long answer is that I hunt with the loads that are blowing out the cases, so prefer to have just one zero and one set of bullet performance expectations.

And Larry - thanks.

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RicinYakima posted this 07 February 2024

One of the issues dealing with the 8.15 x 46R rifles is that there is no standard rim cut, rim thickness or headspace. It is even worse than trying to deal with the 32 WCF and 32/20 cases. 

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Wilderness posted this 07 February 2024

Thanks to all for your additions to the knowledge pool.

As regards correct headspace, I note SAAMI give 0.063" for the .30-30 rim. In measuring a dozen or so Winchester .30-30 rims I found actual thicknesses all the way from .054" to .062". Some old Kynoch .32-40s measured .053" across the board.

I was unable to find the specs for a .30-30 chamber, but it would presumably be at least .063" plus some range of tolerance. [Edit .070" - thanks Bud]

Put those together, and even without wear in the rifle you have a case that can be shunted several thou, perhaps ten thou or more, in firing [Edit .017" max]. That shunting contributes to case stretch, but can be eliminated by getting the shoulder forward to where it takes up any fore and aft slack.

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Wilderness posted this 08 February 2024

Here’s another example of a blown out shoulder (and body), no doubt unintended, .30-30 on the left, .303 on the right for reference. We don’t have to guess what happened.

I found it in the rubbish bin at the range. Headstamp is PPU, so definitely a good advertisement for PPU brass.

What I found interesting, and relevant to part of this discussion, is the lack of expansion of the back third of the PPU case.

 

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RicinYakima posted this 08 February 2024

At our local range a few years ago, I could not stop a guy from shooting 303 Savage in his 303 British SMLE. I tried to tell him the factory rounds he was shooting were worth $5 each, but he kept banging away the whole box. Cases were scrap when he was done. 

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Spindrift posted this 30 January 2024

When I need to move the shoulder forward, I use the method with an oversized expander followed by a correctly adjusted FL die. If you own a Lee decapping die, you can turn this into an affordable and flexible expander die. You can swap the decapping mandrel with any of the Lee FL mandrels. These are sold separately, and can easily be polished down to desired caliber.

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linoww posted this 02 February 2024

I simple leave the Imperial Sizing Die wax on the case every time. Then neck size and reload and headspaced on the the shoulder. BUT it only works for cases dedicated to one rifle. 

 

That's exactly what a fellow showed me 40 years ago. And i've used it ever since with good luck.

"if it was easy we'd let women do it" don't tell my wife I said that!

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Premod70 posted this 06 February 2024

If a firearm has excessive headspace the firearm should be repaired to industry standards, jmho. I know plenty can be done as a work around to make the firearm function but be mindful you are not to live forever and whomever the firearm is pasted along to may not be as knowledgeable and harm themselves thinking Grandpa’s smokepole was safe because they saw him fire it all the time. Always side on the side of safety.

Forrest Gump is my smarter brother.

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Ken Campbell Iowa posted this 07 February 2024

it occurs that might be time to thank MP1886 and Larry Gibson for their several years of posting original thoughts here ... I sure have learned a lot from them.   thanks guys !! ..

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

an entirely different subject, but as my mind wanders it comes to me that a really good hound dog barks a lot ...  

ken

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Premod70 posted this 08 February 2024

Blowing the shoulder forward does give you a work around for excessive headspace but by doing so does not make for a safe firearm as the case is not supported ahead of the rim where it would be in a correctly headspaced rimmed case firearm.

Forrest Gump is my smarter brother.

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MP1886 posted this 08 February 2024

Blowing the shoulder forward does give you a work around for excessive headspace but by doing so does not make for a safe firearm as the case is not supported ahead of the rim where it would be in a correctly headspaced rimmed case firearm.
Think about what you just said. The rifle would have to have a massive amount of excess headspace to expose past the solid web of the case. The 30-30 is a low pressure round and if the rim isn't fully seated and exposes a minute amount the case ahead of the rim there's no way it's dangerous. I'm not saying this is the thing to do, but putting it into perspective.  If there WAS A LOT of the case exposed I'm not certain if the rifle would even fire because it's designed to not fire if out of battery by a certain amount. Let me tell you about the 1903 Springfield. Because of it's "coned breech" the case isn't fully chambers to the extractor groove. Many condemn this. 

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mashburn posted this 10 February 2024

Hello Ricin

Dad gum it, I gave two complete boxes, of factory .303 Savage ammo to a friend of mine. I hope he appreciated them, but if I had to do it over again, I would do the same, he needed them and I didn't, and he was a friend. And good friends are hard to come by, especially if you are a hardheaded, grumpy old fart like me.

Mashburn 

David a. Cogburn

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Wilderness posted this 10 February 2024

I am aware of another interesting case forming venture - turning .22 SHP into .30-30 by firing the former in the latter. Worked just fine, and don't think what comes out the front is harmless. They were being used for butt of the ear finishers on pigs.

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