Heavy Bolt Lift in New Chamber

[Rset]

Check trim to length after full length resize.

Case OAL are at least .010 below chamber length.

 

[Dusty Stevens]

Try a ring die/small base die then bump them to see if they fit better. Gotta reset them even smaller to get past the memory of the old chamber

 

[gunsandgunsmithing]

Try a ring die/small base die then bump them to see if they fit better. Gotta reset them even smaller to get past the memory of the old chamber

It sounds like "memory" is the key word here. I think if he tries new brass, his worries will go away. I think I mentioned this earlier but we haven't gotten to that point quite yet, to prove it right or wrong.

But I think we agree.

 

[searcher]

If I read all correctly - your loaded ammo loads fine - and the bolt closes without a problem. If that is the case - bumping your shoulders back more could be adding to your problem of shoulders already pushed back too far. This can be determined pretty quickly by firing a few rounds loaded down at least 5% from your current load - and with the bullets seated long enough to be a solid jamb. After firing - if your shoulders got blown out way past where they were prior to firing - you know you were pushing them back way too much - which would have contributed to the problem - if not caused it in entirety.

 

[Rset]

If I read all correctly - your loaded ammo loads fine - and the bolt closes without a problem. If that is the case - bumping your shoulders back more could be adding to your problem of shoulders already pushed back too far. This can be determined pretty quickly by firing a few rounds loaded down at least 5% from your current load - and with the bullets seated long enough to be a solid jamb. After firing - if your shoulders got blown out way past where they were prior to firing - you know you were pushing them back way too much - which would have contributed to the problem - if not caused it in entirety.

Not sure I completely understand your comment. I normally bump the shoulders back .002 and do not normally have an issue. I have just prepped some cases with a .004 bump and am going to see if it makes a difference. Neither I would consider so excessive that it would create a problem, but not sure what you would consider "way out". I may have to go to new brass, but with only 2 firings on the old cases, I find it hard to believe they have already taken a memory to the old chamber.

 

[Rset]

Try a ring die/small base die then bump them to see if they fit better. Gotta reset them even smaller to get past the memory of the old chamber

Thanks for the suggestion. I do find it hard to believe that the old cases would have taken a memory to the old chamber after just 2 loadings, but who knows. I think before I get a small base die and spend the time to try to fix the old brass, I will just start with new if the next round of "fixes" don't get ant better results.

 

[Uncle Ed]

FYI, on Lake City 7.62 cases fired in machine guns I use a carbide .45acp die to reduce the base diameter, then size in a normal die. Its a cheap bastards ring die, so another die might also work. A 30-06 die will also work with "FAT" 7.62 cases so you might have something that might work with the dies you have. (then you can join the cheap bastards club)

As a side note I buy bulk once fired Lake City 5.56 and 7.62 brass and always size them the first time with a small base die. But the 7.62 cases may need to be sized first with a .45 acp or 30-06 die. This helps keep you from dislocating your shoulder if you try and use a standard die.

 

[searcher]

Not sure I completely understand your comment. I normally bump the shoulders back .002 and do not normally have an issue. I have just prepped some cases with a .004 bump and am going to see if it makes a difference. Neither I would consider so excessive that it would create a problem, but not sure what you would consider "way out". I may have to go to new brass, but with only 2 firings on the old cases, I find it hard to believe they have already taken a memory to the old chamber.

I'm thinking that maybe your shoulders were not blown all the way forward before you bumped them. What I meant by seating "way out" is seating a bullet that is hard into the lands when the bolt is closed. Upon firing, this will ensure that the shoulder is blown forward fully - or nearly so. If, after doing that, you find that your current die setting results in a bump that is more than the .004" on your new blown-out case measurement from base to shoulder, you will know your cases were not previously fully blown forward. This situation is pretty common - as if your new chamber is longer than your prior - and you did not blow your brass out to fit the new chamber before arriving at a new set-back length, your accuracy will become erratic and in extreme cases - your brass will get smacked back to the bolt face hard enough to enlarge the base of the brass, effectively wedging it in the chamber - resulting in the hard bolt lift - and can also result in cratered primers. Taking a piece of brass previously fired in another chamber (or new brass for that matter) and firing it without jamming the bullet will seldom (almost never) push the shoulder forward fully. The problem is compounded though - when the new chamber is longer. Good luck!

 

[cheek9075]

I have a 22beggs that worked fine for the first few firing. Then I got heavy bolt lift. I found the issue was with the reamer the chamber was cut with. Hand cut the chamber with correct reamer, now all good. Issue was in the web of the case. I opened up the web with the correct reamer. Brass now has numerous firings on it with no issue.