case neck collapse on .376 steyr brass


October 12, 2003, 01:25 PM
I'm trying to seat bullets in some brand new unfired hornady .376 steyr brass, and the case necks keep collapsinginto the case body, flattening out the shoulder.The mouth is staying fine, and the bullet is aligned in the case mouth fine.I had it set where it was only seating about 1/4 in. into the case and still collapses the case neck straight down in to the body essentially flattening the shoulder.Any advice would be greatly appreciated.I tried a little case lube on the bullet, No help at all.I have the RCBS dies set up like the manual says, with the seating die 1/8 inch above the shell holder when all the way up.I tried resizing the brass and it did not help either.I'm using Hornady .225 Spire points as they load in there factory loads.

If you enjoyed reading about "case neck collapse on .376 steyr brass" here in archive, you'll LOVE our community. Come join today for the full version!
Car Knocker
October 12, 2003, 04:50 PM
Just thinking of a checklist I would make if I were having this problem, some of which you have done already:

Measure bullet diameter and sized case mouth diameter for compatability.

De-burr case mouth.

Slightly flare case mouth.

Run empty case into seating die to check and ensure there's not excessive crimp.

Seat and crimp in separate operations.
-Back seating die out a full turn, back seating stem out, then gradually turn stem in until correct OAL is achieved. If no collapse, back stem out again and screw die down to crimp. If this works, get extra die to crimp with.

October 12, 2003, 09:24 PM
I backed the seating die out a full turn and adjusted the seating stem down to the correct setting for my desired overall case length, and it is working perfectly, no case neck collapses.My only question is, is there any need to crimp since it will be used in a bolt action rifle?The bullet is plenty tight in the case.
The rcbs guide to set up the dies says to set up the die run the shell holder up, screw the die down til it touches the shell holder, then back it out 1/8 of a turn, never more, it should leave about the thickness of a nickel between bottom of die and top of shell holder.
When I backed it out a whole turn, it left about the thickness of a nickel between shell holder and die, is there any reason for concern since it's more than the advised 1/8 of a turn??I cant see any reason why it would matter.

October 12, 2003, 10:14 PM
If you choose not to crimp, and it is a choice, you might want to check cases in the magazine for bullet setback under recoil - some say the gun recoils back and the cartridge doesn't so the front of the magazine hits a hammer blow to the front of the bullet. People have arranged magazines with shoulders to match the case and sponge padded center channels in some magazines to deal with these issues. I wouldn't fiddle with the Steyr magazines here nor do I think it necessary, just making conversation.

In a Steyr Scout or as here strictly speaking pseudo Scout there is always the possibility of leaving a loaded magazine in the butt stock for many shots either single loaded or refilling the front magazine only for a series of shots - something to think about. For all I know you have a Pro Hunter or something else but I gather it is a Scout, mine is.

I started some time ago by reading Why Not Load Your Own by Townsend Whelen and Principles and Practices by Naramore and Phil Sharpe's book - the only experts I've read who had all the answers were the Herters:D Of course Herters is out of business and Rock Chuck Bullet Swages just keeps chugging along.

Notice the variety of seating die arrangements - including the RCBS Vickers type, the many variations of sliding sleeve and the Redding shell holders of varied lengths and however likely it be that there is a best process for your equipment you may be sure that somebody else is getting good results doing it differently.

More specifically 7/8-14 threads as used are somewhat sloppy and the notion is that the shell holder face is square and normal to the ram and stroke and the die face is square and normal to the centerline and the die is symmetric and everything will line up peachy keen when butted and so produce a cartridge with minimum run out and maximum accuracy. After looking at your loaded ammunition and doing whatever you care to do for an estimate of runout you may choose to start the bullet then withdraw the ram and rotate the cartridge case a half turn or whatever before seating the bullet to final depth. Often this helps, sometimes it hurts.

Then too did you check the cases for overall and neck length? square the mouth and chamfer or take it that new cases must be the perfect length?

October 20, 2003, 03:21 PM
I came across this and there is a warning about dies (Hornady) setting shoulder back, but it may help you with your RCBS problem. HTH

376 Steyr (

If you enjoyed reading about "case neck collapse on .376 steyr brass" here in archive, you'll LOVE our community. Come join today for the full version!