308 cast bullet fed from the magazine misses the chamber mouth and jams

[Wreck-n-Crew]

I also question the sizing. I follow the instructions of putting the bullet and GC through a sizing die and they come out as .309. We can't talk accuracy here or about .310 or .311 being better and more accurate because I tried sizing them through a .313 die and the GCs fell off. I think I'll leave the bullets cast size (.311) and crimp the GC by using a .270 crimp die and shortening a 270 shell to accomplish this.

I was talking about the case neck not the bullet. What sizing die are you using and the process to size and check case neck tension?

IF your not properly adjusted then the neck tension may only be at the case mouth where it is sized. When you seated deeper you blew past what little of the neck was holding the bullet and it dropped through. At least that's what it sounds like from my experience.

 

[wish-a-lot]

The 270 crimp die crimps to .306 which is the OD of the 270 neck. The gc just fits snugly in the crimp die hole. shaving the neck of the 270 the same amount as the height of the Gas check allows the GC to sit on the top of the shell for support when setting the crimp.

 

[wish-a-lot]

I was talking about the case neck not the bullet. What sizing die are you using and the process to size and check case neck tension?

IF your not properly adjusted then the neck tension may only be at the case mouth where it is sized. When you seated deeper you blew past what little of the neck was holding the bullet and it dropped through. At least that's what it sounds like from my experience.

I use the full sizing die from Lee. The bullets are put through the Lee bullet sizer at .309

 

[dgod]

I use the Lube-A-Matic to size my ammo, In ALL= of the 30 caliber loads I make, the Gas Checks are crimped into the Bottom./ Boat Tail section. I use the Hornady Gas Checks, they seat and clamp very well, I have only had one come loose, it was reseated & sized, problem solved. I have the same luck with 452 Gas Checks. I rarely use them because I don't load Pistol Bullets that go fast enough to require them.

I haven't tried it, but I have been told that the Lee Sizer (Works in the Press) will crimp Gas Check too.

I've not had a Gas Check that caused any bulge in the case after being loaded.
Good Luck
Dan

 

[Elkins45]

Based on similar experiences I've had with a converted Mauser, seat them out farther and work the bolt more vigorously.

That thing you mentioned with the 270 seems like a bad idea.

 

[wish-a-lot]

Based on similar experiences I've had with a converted Mauser, seat them out farther and work the bolt more vigorously.

That thing you mentioned with the 270 seems like a bad idea.

Seating them out further exasperates the problem of the bullet hitting the rifling even sooner and already it's hard to close the bolt.
The crimping of the GC in the 270 crimper gives a perfect and tight fit if the crimp is set right. It's also fast and easy.

 

[PapaG]

I'm not smart enough to sort this out without a couple more answers but I'd really like to try. What is the diameter of the nose part of the bullet...the parallel, bore riding part? Do you not size the bullet and seat the gas check at the same time? I remember .309 as your sizing diameter. If you are using Hornady gas checks and have well cast, filled out bullets they should crimp on while sizing. If your expanding plug is proper, there should be several thousandths "squeeze" on the bullet by the neck of the cartridge case. You should be able to seat one, after belling the case mouth, and then just crimp enough to remove the flare. A good amount of finger pressure should not make the bullet move. Seat to the crimp groove, or if this puts the gas check below the neck of the case, adjust out a little.