Cast bullets seated below the neck?

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  • Last Post 27 December 2012
mike morrison posted this 20 July 2012

i was looking at the cast boolets site and see a noe mould in the group buy section that is 311247. this is specific for the 300 blackout. the drawing shows the bullet seated well below the neck. I have always read and heard that the base of the bullet should not be seated below the neck. How will this effect this loading. what problems will occur if any. will bullet hardness effect this. should the bullet wear a gascheck? just questions that came to mind as i looked. any comments or info. just curious. mike

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onondaga posted this 20 July 2012

The 311247 is a flat nose spitzer , gas check design with conventional pressure lube groove and driving bands. There is nothing peculiar or innovative about the design.

Gas checks should generally be used on bullets designed for them. Gas checks have obvious function and also protect the bullet base from nicks/dings that affect flight.

The new Lee mold for the 300 blackout/whisper is much more interesting with a dual purpose design base and tumble lube design:

http://www.midwayusa.com/product/938614/lee-2-cavity-bullet-mold-tl309-230-5r-30-caliber-309-diameter-230-grain-300-aac-blackout-tumble-lube-5-ogive-radius>http://www.midwayusa.com/product/938614/lee-2-cavity-bullet-mold-tl309-230-5r-30-caliber-309-diameter-230-grain-300-aac-blackout-tumble-lube-5-ogive-radius

Seating depth, and hanging tails into the case aren't a concern when shooting these low velocity designed cartridges. Engaging the lands by kissing the bullet there with LOA is working the best with cast bullets in this application.

Gary

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EdS posted this 20 July 2012

My first experience loading cast bullets in a bottle-neck rifle case was with the 30-30. I'd worked up some nice, moderate pressure loads with the Lyman 31141 and then had the opportunity to try the Ranch Dog design in a similar weight. I had to seat these deeper in the case in order to get them to chamber in my M-94. The first shot resulted in a split at the neck-shoulder junction. These were once-fired Winchester cases that had been Properly resized. Thinking it a flaw in the case, and seeing no other signs of excess pressure, I fired a second round - with the same result. Of course, I pulled the remaining bullets. So, my vote is to keep the base of the cast bullet in the neck if possible, or drop way down in powder charge and work up carefully. -Ed

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mike morrison posted this 21 July 2012

if the attachment worked here is a pic of the drawing that shows the bullet base below the the neck. what if any problems with this. seems it would be ok as seems to be desined this way. just different from what i have learned. the lee bullet looks like it will seat below the neck. just seems to go against what i have learned. have i missed something.?? i read the bullet if soft enough will bumb up and be larger when entering the neck. could be the case with the experience described above. that experience is what made me wonder when i saw this. m

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rockquarry posted this 21 July 2012

There are likely some exceptions, but from both an accuracy and bore leading standpoint, I can't recall a problem with seating a cast bullet below a case neck. My work has been mostly with several .30 caliber gas check designs in most of the popular .30 caliber cartridges. I always use a crimp-on gas check that has been crimped on, never just placed on the base.

Like most cast bullet shooters, I would prefer the base of the seated bullet to be in the neck rather than below it, but that's not always possible.

This is another cast bullet lore “fact” that deserves closer examination.

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mike morrison posted this 21 July 2012

I guess if the lube is not exposed to the inside of the case and the powder there should be no problem. Maybe lube exposure was the reference and i missed it. just caught my attention and raised the question. thanks m

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mike morrison posted this 21 July 2012

I guess if the lube is not exposed to the inside of the case and the powder there should be no problem. Maybe lube exposure was the reference and i missed it. just caught my attention and raised the question. thanks m

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rockquarry posted this 21 July 2012

Below neck lube exposure should be minimal, of course, but some exposure won't usually be detrimental. Ball powder is the worst offender here as far as sticking to the lube and a very soft lube like half & half that becomes runny in hot weather only makes things worse. I used to use a lot of Accurate Arms 2230 (ball powder) in the .308 and other cartridges with bullets seated below case necks. I never experienced a problem, but always used a stiff lube like LBT Blue.

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jhalcott posted this 04 December 2012

It is supposed to be available NOW. This is a heavy weight bullet designed to go subsonic and work in semi autos. I'm not sure about the pressures developed but they should be mild. As far as I know the Lee Liquid Alox for tumble lubing isn't harm full to powders. At least there have been no issues with it in MY experience.

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CB posted this 04 December 2012

The case only has about a 1/4 in neck. If you want heavier bullets than about 120 gr, all that bullet has to go somewhere.

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linoww posted this 04 December 2012

I had a slight boattail plainbase 30 caliber.it shot like a shotgun at 50 yards.Gas cutting was enormous.I'd be curious how the Lee"dual purpose” bullet does.As for GC bullet with no GC used i have had no problems using themas plainbase without GC at appropriate velocities.

I think Pat I won some matches with a 250+g 30 caliber some years back.He might have and answer to shooting these heavy things.

G-

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

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MT posted this 05 December 2012

I would echo the remarks of rockquarry in that, although there could be exceptions, it probably isn't a problem. I regularly load a 300 Savage in a Savage 99 with a RCBS 180 grain bullet and an appropriate charge of H4895. The bullet has to be seated deep to work through the magazine; no leading or other problems MT

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linoww posted this 06 December 2012

MT wrote: I would echo the remarks of rockquarry in that, although there could be exceptions, it probably isn't a problem. I regularly load a 300 Savage in a Savage 99 with a RCBS 180 grain bullet and an appropriate charge of H4895. The bullet has to be seated deep to work through the magazine; no leading or other problems MT

My experience as well.

g-

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

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onondaga posted this 06 December 2012

I had an exception!!!

The Lee CTL312-160-2R sized to .3105” for my Sako L57 rifle in .308 has the best accuracy of all my bullet molds for .308 Winchester. After I developed a load with terrific accuracy, I couldn't have been happier until I decided to chronograph my perfect load with the bullet seated having the gas check area just below the neck and at the accuracy sweet spot for the load.

I setup the chronograph and fired 10 shots, the target at 50 yards had one ragged hole. The face of the chronograph had six dents from gas checks slamming into it.

There is no way for me to determine if the checks are coming off at the muzzle or if the case neck is peeling them off. But it happens, and I'm blaming it on the bullet being seated below the neck.

Gary

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linoww posted this 06 December 2012

Only way to really test would be fire with the bullet above the case neck junction.If had great accuracy why worry and it proves it doesn't generally matter.If they came off before they went down the bore i would expect accuracy to be pretty bad.Heck they were originally supposed to come off at the muzzle as Barlow designed(stole the idea from the Brits actually)Maybe he knew something

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

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Ed Harris posted this 06 December 2012

If fast-burning powders are used, which do not fill the case, AND if the bullet base protrudes into the powder space, AND is not supported, the bullet base may be upset upon discharge to conform to the case interior neck and shoulder, creating a “nail-head” effect which can dangerously increase pressure.

While I have not personally experienced this in cast bullet loads, this is the reasoning for the 11 degree, 30 minute blend between the 23 degree shoulder, and the neck of the 5.56mm NATO chamber, to prevent that from occurring with the longer M856 tracer bullet used in linked ammo for the M249 machinegun.

Federal cartridge had recalls some years ago of 6.5x55mm and .243 Winchester factory ammo which caused blowups believed to be from this mechanism.

If you are going to load cast bullets having their bases protruding below the neck, you want to use a powder of a burning rate which permits safe pressures and useable velocity with a compressed case full of powder. You want to avoid airspace which could result in the powder “plug” becoming a projectile and the protruding bullet base becoming an obstruction which can be upset into the surrounding unsupported adjacent area of the chamber.

73 de KE4SKY In Home Mix We Trust From the Home of Ed's Red in "Almost Heaven" West Virginia

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tturner53 posted this 06 December 2012

That new Lee design is interesting. Don't have a 300 BO, but I'm wondering about other cartridges? How long is it? Actual as-cast diameter? I'm thinking I need to get one. Maybe try it in a H&R 30-30 single shot. Probably have to push it to stabilize in a 10” twist.

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onondaga posted this 06 December 2012

http://www.castbulletassoc.org/view_user.php?id=2514>tturner53:

I cast the new Lee TL309-230-5R in a #2 clone alloy. They drop .311-.312” diameter for me. I get a length of 1.353". The largest diameter I get on the long nose ogive is .300-.301. Because of the small nose diameter and very long ogive, you can seat this bullet very far out till they bear on the rifling in a single shot rifle. I favor seating to .005” engagement of the rifling in my single shot 7.62X39 and recommend that for your 30-30 single shot.

The bullet can also be shot backwards or base first  having the appearance of a large meplat flat nose bullet. If seated that way, seat them to engage rifling .005” also.....They won't look very long seated that way and most of the bullet will be in the case. If you do that, start low and work up your load. you can run into pressure with so much of the case filled with lead.  However with a 230 grain flat nose bullet in 30 cal. you don't need very much velocity to really slam big game. About 1500 fps will give over 1,000 foot pounds at 100 yards with that heavy bullet.

I wouldn't worry about your twist rate at all because of the bearing area length/surface on this bullet. Look again at my picture up the page.

Gary

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tturner53 posted this 07 December 2012

That does it. Thanks for the info. I'm getting one. And a Lee 45-250 REAL mold for my ROA. I have Midway gift certificates to spend. While on the Lee bandwagon, today I ran a sample cast from a Lee .454 RB mold, brand new. Hit it with carb cleaner, warmed it up, and went to it. Worked great. Then I fired up the ww pot and cast some Lee .429-255 from a discontinued 6 cavity mold I borrowed from Grant M. First cast gave good bullets. Good times. AND, I just got my new Redding .22 K Hornet dies 5 minutes ago! More gift certificates. What a wonderful day.  EDIT: I looked and can't find the BC on the .300 BO bullet. Gotta be up there.

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onondaga posted this 07 December 2012

http://www.castbulletassoc.org/view_user.php?id=2514>tturner53; Lee doesn't list the BC on the 300 BO, or anywhere I can find. My software puts it at ~.673 .  Of course, that is when you fire it point first !!!!! Base first the BC is only ~.300 .

Gary

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Ken Campbell Iowa posted this 07 December 2012

tturner sez: That does it. Thanks for the info. I'm getting one.


interesting ...btw i have a special throat reamer ...  goes from 0.313 to qbout 0.297   at 1.5^   ...  tapers ...   let me know if you would like to play with it ...a ppg reamer.    you could gently do that by hand.

remember... you can remove metal .. you cannot put it back  tho ..

( g )

or you could send me the barrel y i could do it for you ...but postage is cheaper on the reamer .. ( g ).

ken

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