Hitting pressure after a bit of load development

[wind gypsy]

Here is my take on it. I will gladly give up 75-100 fps for a barrel that shoots everything well rather than a "fast" barrel that is super sensitive to seating depth or only likes one load. But, then again, I have never been one to chase velocity. I can always dial up another click.

I wouldn't call ACE, krieger, benchmark, PVA, PBB, bartlein, hawk hill, and on and on "fast", i'd call them normal. And they aren't any pickier than tikka barrels in my experience.

Speed is only part of it. Even with a faster barrel, tikkas still seem to get sticky bolt lift more than other actions.

 

[Harvey_NW]

Speed is only part of it. Even with a faster barrel, tikkas still seem to get sticky bolt lift more than other actions.

I agree, but IME only if you're standing on it. I can usually get up to book max or a grain over before I start seeing it. Except for VV load data, I got 11gr over their published max

 

[wind gypsy]

I agree, but IME only if you're standing on it. I can usually get up to book max or a grain over before I start seeing it. Except for VV load data, I got 11gr over their published max

I've fought it with a couple in a variety of factory loadings. Sig, berger, norma, federal.. You name it, sticky bolt lift at modest velocities. That's not counting the 556 loadings in a 223 barrel.

 

[coast range]

All valid points. You guys think I should drop 1 gr. And see? Or a little more and check groups?

 

[ckleeves]

Doing load development on a new barrel with virgin brass for the first 100 ish rounds is a good time to figure out what bullet and powder the barrel likes and get all your brass fire formed but that’s about it.

What’s safe on a barrel with 20 rounds on it with virgin brass can end up real spicy in that same barrel with 200 rounds on it in 2x fired brass.

 

[HandgunHTR]

I've fought it with a couple in a variety of factory loadings. Sig, berger, norma, federal.. You name it, sticky bolt lift at modest velocities. That's not counting the 556 loadings in a 223 barrel.

Just a thought here, but could your sticky bolt lift actually be due to a burr on the camming surface at the back of the bolt? I had one that was doing that and when I dug into it, I noticed a tiny bit of galling there. I little lithium grease cleared it right up.

 

[wind gypsy]

Just a thought here, but could your sticky bolt lift actually be due to a burr on the camming surface at the back of the bolt? I had one that was doing that and when I dug into it, I noticed a tiny bit of galling there. I little lithium grease cleared it right up.

I grease lugs and cocking ramps. Don't know if it's the absolute best grease, basic birchwood casey gun grease is what I have.

 

[Trogon]

I've fought it with a couple in a variety of factory loadings. Sig, berger, norma, federal.. You name it, sticky bolt lift at modest velocities. That's not counting the 556 loadings in a 223 barrel.

I have same issue. Loading for 6.5-284 Im running into sticky bolt even way down at 1gr over min book charge about 1 in 5 rounds, then gets worse as I go up from there. And thats with standard bump on the should, no jam bullet, careful powder measure, etc. I dont clean much, so Im going to investigate the potential for carbon ring. N565, IMR4350, IMR4955 all show erratic pressure.

 

[wind gypsy]

I have same issue. Loading for 6.5-284 Im running into sticky bolt even way down at 1gr over min book charge about 1 in 5 rounds, then gets worse as I go up from there. And thats with standard bump on the should, no jam bullet, careful powder measure, etc. I dont clean much, so Im going to investigate the potential for carbon ring. N565, IMR4350, IMR4955 all show erratic pressure.

I know some of the 284 based cases have occasional trouble with differences in dimension at the case web with various brass and reamers than can lead to that as well.

 

[Harvey_NW]

All valid points. You guys think I should drop 1 gr. And see? Or a little more and check groups?

I would drop 1-1.5 to be safe if you ever plan to hunt where you could see moisture on a case or something. If it grouped fine before it will group fine or better even sometimes with a lower charge.

I have same issue. Loading for 6.5-284 Im running into sticky bolt even way down at 1gr over min book charge about 1 in 5 rounds, then gets worse as I go up from there. And thats with standard bump on the should, no jam bullet, careful powder measure, etc. I dont clean much, so Im going to investigate the potential for carbon ring. N565, IMR4350, IMR4955 all show erratic pressure.

I know some of the 284 based cases have occasional trouble with differences in dimension at the case web with various brass and reamers than can lead to that as well.

This. Definitely measure the web area of a fired case and make sure it's in spec. I had a 284 Win that did the same thing and it ended up being under spec at the back end, either from conflicting tolerances with it being such an old cartridge, or a worn reamer. Gunsmith touched it up with a new reamer and it was smooth sailing.