Bolt Resistance w/ Annealed Brass

[bill123]

I think that I saw a thread like this recently but can't find it now.

I was shooting with 3x fired Lapua brass today that I had annealed a few months ago. When I ejected the fired brass, the bolt lifted easily about half way and then required more effort to open the rest of the way. sliding the bolt backwards was effortless. Primers look normal. I shot 1 round over a chrono and the speed is normal. There is a slight scuffing mark on the head of a few pieces of brass that follows the direction of the lettering on the head. Groups were good. I'm shooting a .308 w/ 155.5gr Bergers, 46.1 gr Varget, CCI primers.

During the same shooting session, I shot identical loads but with un-annealed brass. Also shot some factory ammo. No problems with either.

Any ideas?

 

[jlow]

If you think it was caused by the annealing, the first question you should ask yourself is did you properly anneal the brass? Annealing is not rocket science but it can go wrong.

 

[L-46]

In my experience you have to resize the case base more,
start by measuring a few cases of both some that click and some that do not.

 

[bill123]

If you think it was caused by the annealing, the first question you should ask yourself is did you properly anneal the brass? Annealing is not rocket science but it can go wrong.

I used a bench source. That doesn't mean I didn't over anneal (I assume under annealing would have had no effect).

Is what I'm experiencing what people refer to as a "click" when opening the bolt. If so, what causes it?

 

[ShootDots]

The possibility exists that you annealed a bit far down on the case body, thus creating a softer body than should be. The brass expanded a tad more than normal and when it retracted it did not retract far enough. I think that once the case body hardens up somewhat, your difficulties should dissipate. If you have a small base die, for the next firing or 2 you might consider using it..

 

[jlow]

I guess this is what I was thinking. Did you use Tempilaq to ensure that the head of the case was not annealed?

 

[ShootDots]

If you think it was caused by the annealing, the first question you should ask yourself is did you properly anneal the brass? Annealing is not rocket science but it can go wrong.

I used a bench source. That doesn't mean I didn't over anneal (I assume under annealing would have had no effect).

Is what I'm experiencing what people refer to as a "click" when opening the bolt. If so, what causes it?

That "click" is the base of the case closest to the extractor groove, has expanded a shade too much. Once again, the small base die MAY "fix" that problem too..

 

[dickn52]

Did you resize before or after the annealing?

 

[Webster]

Tony Boyer's book addresses the click when opening the bolt. He says as the case body work hardens it don't spring back from the chamber wall. The click is when it breaks free. You need to size the body a little bit more. Get Tony's book for exact details. Midwest charged about $9.50 shipping for the book. Someone else on this website was nailed for over $15 somewhere else.

 

[jonbearman]

You can get tonys book on amazon I believe and they have a flat rate shipping charge that is not 10.00.

 

[bill123]

Jlow I did use tempilaq.
Dickn52 I resized after annealing but did not reset the bushing die from the unannealed setting. Also, I do not use an expander.
Shootsdots & Webster, it seems as if one of you is saying that the problem is too soft brass and the other is saying it is from hardened brass. Can you explain? I'll check out Boyers book.
Thanks

 

[jlow]

We are of course just guessing since we don’t have all the information you have. You mentioned this happened after you annealed and so one possibility is you over annealed and the head became soft and so would expand more which may cause that extraction artifact you explained. However, if you used Tempilaq and is sure that you did not anneal the head, then this is not your problem.

Maybe it is your case head hardened as others have said, but this seems to be a bit early? I mean the OP is talking about 3x fired Lapua brass?

 

[bill123]

Is there a chance that it could be caused by too much or too little FL sizing? I did not measure and adjust the headspace on the annealed brass. I just used the FL bushing die with the same setting that I had previously used on unannealed brass.

 

[noload]

I suspect the base (just above the web )on the brass that clicks is slightly bigger in diameter then the brass that does not click. Put the brass on a concentricity gauge and compare base diameters. It only takes 2 tenths difference between good brass and bad to screw you. Another way to see the interference, is to polish the click brass and rechamber it and look closely for where it scratches the case. Thats your problem (scratch area).

 

[DeltaBravo]

bill,

Tony's book says to measure the shoulder/body junction with a caliper, and lock in that setting; then FL size the brass. The caliper should then slide down the body about 1/8" - if it goes farther, you've oversized; under and you've not sized enuf. Try this first, but Tony's book is still the best reference.

Dennis

 

[bill123]

bill,

Tony's book says to measure the shoulder/body junction with a caliper, and lock in that setting; then FL size the brass. The caliper should then slide down the body about 1/8" - if it goes farther, you've oversized; under and you've not sized enuf. Try this first, but Tony's book is still the best reference.

Dennis

Thanks all. I'll try your suggestions. Dennis. Do you recall where in Tony's book it's written? Just found my copy.

 

[Webster]

Page 114 in Tony's book.

 

[dalej]

I think that I saw a thread like this recently but can't find it now.

I was shooting with 3x fired Lapua brass today that I had annealed a few months ago. When I ejected the fired brass, the bolt lifted easily about half way and then required more effort to open the rest of the way. sliding the bolt backwards was effortless. Primers look normal. I shot 1 round over a chrono and the speed is normal. There is a slight scuffing mark on the head of a few pieces of brass that follows the direction of the lettering on the head. Groups were good. I'm shooting a .308 w/ 155.5gr Bergers, 46.1 gr Varget, CCI primers.

During the same shooting session, I shot identical loads but with un-annealed brass. Also shot some factory ammo. No problems with either.

Any ideas?

Your load is fairly warm. Don't think annealing changed anything. I switched to Lapua Palma brass because a load similar to yours was expanding primer pockets. Suggest you measure extraction groove diameter before and after firing a few rounds. If there's any expansion you're over-pressuring brass. My load was 155, 47 gr Varget, F210M, same load with Lapua Palma brass using CCI-450 (small rifle magnum) gives me 3070 fps and excellent brass life.

 

[Turbulent Turtle]

Have you trimmed the brass recently?

 

[Webster]

I know the reload manual's are conservative but the Berger Manual gives:
155.6 GR Match Fullbore Target BUllet
44.6 GR varget for 2764 FPS Approx. fill ratio 100%. Your at 46.1 grains???