Bumped shoulder too far

[antelopedundee]

No. I didn't realize I was bumping them any further than I had in the past when I was doing it. I hadn't loaded for this gun in quite a while. I think last time I had used the dies was 2016. I really don't shoot this gun much and it's my only 30-06ai. I must have messed with something at some point to change where I had it set and didn't double check when I resized the cases.

Sometimes it happens that when you thought you tightened the lock ring you really didn't tighten it enough.

 

[L.Sherm]

. It appears my lock ring was loose and the die got screwed in too far.

I'm not much of a hornandy fan but I sure do like there lock rings for dies, ive changed all my dies except whiddens to them

 

[bigbull]

So I bumped the shoulder too far back on my 30-06ai brass. So far that I'm getting case head separation on every round. I'm planning to pull bullets out so they are jammed into the lands and basically re-fireform. Posting this to see if there are any better ideas out there other than necking up and making a false shoulder. Thanks!

Your brass looks fine based on the cutaway pics. Re-fireforming the brass is a good idea, if you want to save it.
\reduce the loads accordingly or you will experience very high pressures, you will also need to resize the necks to have enough tension to firmly hold the bullet.
BB

 

[Vettepilot]

What abount using a very small amount of lubricant on the brass when firing them with reduced loads and jammed bullets? This diminishes the chambers hold on the brass, and helps ensure the brass stays back against the bolt, thus blowing the shoulder forward instead of stretching the case.

Vettepilot

 

[Josh06]

Well, I couldn't wait and went to the range this afternoon. I would have to say it was a failure overall. I didn't have any complete separations but several pieces of brass had that very distinct line where separation would occur. I tossed those and came home with 19 pieces that look good but will need to be checked for thinning with a paperclip. If I ever do this again I would probably set a false shoulder and use the COW method to blow them back out.

Thanks for all the reply's!

 

[Josh06]

What abount using a very small amount of lubricant on the brass when firing them with reduced loads and jammed bullets? This diminishes the chambers hold on the brass, and helps ensure the brass stays back against the bolt, thus blowing the shoulder forward instead of stretching the case.

Vettepilot

Makes sense, wish I would have thought of that or seen this while shooting them this afternoon to try it.

 

[MNbogboy]

Well, I couldn't wait and went to the range this afternoon. I would have to say it was a failure overall. I didn't have any complete separations but several pieces of brass had that very distinct line where separation would occur. I tossed those and came home with 19 pieces that look good but will need to be checked for thinning with a paperclip. If I ever do this again I would probably set a false shoulder and use the COW method to blow them back out.

Thanks for all the reply's!

Actually the head separations may have started on the first firing as 06 brass. The "thin" spots created then are the "weak" spots and are the first to stretch each firing even when bump is set correctly. All or the majority of the stretching happens in the same area each time.
I agree that the cutaway section shows little if any stretching. Using your "paper clip" test on the latest (shiny ring) cases will give you a good feel for the rest.
Although salvaging the last 19 cases that already may be at "half life" is about $10 worth of value.....maybe not worth the gamble of "scarring" your chamber. ??

 

[BountyHunter]

use a lube on the shoulders no matter what method you use.

 

[Vettepilot]

Makes sense, wish I would have thought of that or seen this while shooting them this afternoon to try it.

Yeah, you might try it with the others. The ejector is trying to jam the case forward against the shoulder, then when the firing pin hits, it too pushes the case forward. Then the case expands, and locks in place upon ignition. Case expansion/lengthening then occurs right at the point where we see head separations. With the case and chamber clean and perhaps polished up a bit, then lightly lubricated, the case is more likely not to lock into the chamber as normal, and therefore expand forward in the neck area as desired. Wildcatters and people forming cartridges sometimes use this trick.

Don't do it on a full house load though, because the increased bolt thrust can hammer the gun needlessly.

Vettepilot