Built a new upper and getting early intermittent faint ejector marks on all 5 charge ladders tested, starting from published minimums and going in 0.2gr increments to published max or near published max. Also got very minor cratering in the primers after the 2nd or 3rd round in each ladder. Primers were not flattened at all, no soot on the casings, no extractor swipes, no visible case rim markings, and no other pressure signs that I know of occurred with the above.
I suspect it's 1 or both of 2 things, but I would like feedback for additional info:
1) I made a (very dumb) oversight of not resizing the old brass to the new barrel - it was resized to the old one. When I tried dropping brass into the chamber and letting the bolt drop somewhat slowly (on purpose) by letting the charging handle fall from only about 2/3 or 1/2 way, it still chambered fine. However, when I tried to extract the loaded round using the charging handle, it would take a lot of force and there were no marks on the bullet (ogive or elsewhere) but some had small very small nicks on the shoulder (I think this means I didn't set the shoulder back enough when full length sizing). IIRC if brass is "too big" relative to the chamber, it creates extra pressure. Didn't have factory ammo with me today to compare.
2) I don't think this would do it, but want to ask anyways - I used a honing tool to lap the front face of the upper receiver. I only removed enough material for it to "be even". The anodizing wasn't completely removed all the way around. Sitting the barrel an extra 0.001 or 0.002" back into the receiver from lapping shouldn't be enough to create a pressure issue if a go gauge chambered OK and the round couldn't close on a no-go gauge right?
Stuff used:
New PF chambered Criterion 1:8. BCM upper receiver.
Tried N133, IMR4895, A2520, AR Comp, and CFE223, got early pressure signs in all of them near the published minimum loads.
Hornady brass (4-5 firings each), CCI SRP, Hornady 123gr ELD-M
Stuff I ruled out:
Neck "tension" was about 0.001 and all brass was just trimmed to 0.001-0.004 above published trim length. After running through full length sizing die, I tried to run a .262 mandrel through the neck but the neck was already bigger than the mandrel. I know too much neck tension or long necks can also cause somewhat intermittent pressure issues and think this can rule it out.
I know you can't directly compare barrels and I won't say I didn't make a different mistake in the process - I used the same reloading process as my old 6.5G barrel (along with other cartridges). Was able to go to published max using 4/5 of the above powders with no pressure signs at all. The 5th got about 3/4 of the way up the ladder.
Scale was working properly - other loads were loading before and after loading these rounds and they all gave expected velocities and had no pressure signs (as expected per their loads) in their respective rifles. Primers from the same batch were used as well in some of these rounds without issue.
I suspect it's 1 or both of 2 things, but I would like feedback for additional info:
1) I made a (very dumb) oversight of not resizing the old brass to the new barrel - it was resized to the old one. When I tried dropping brass into the chamber and letting the bolt drop somewhat slowly (on purpose) by letting the charging handle fall from only about 2/3 or 1/2 way, it still chambered fine. However, when I tried to extract the loaded round using the charging handle, it would take a lot of force and there were no marks on the bullet (ogive or elsewhere) but some had small very small nicks on the shoulder (I think this means I didn't set the shoulder back enough when full length sizing). IIRC if brass is "too big" relative to the chamber, it creates extra pressure. Didn't have factory ammo with me today to compare.
2) I don't think this would do it, but want to ask anyways - I used a honing tool to lap the front face of the upper receiver. I only removed enough material for it to "be even". The anodizing wasn't completely removed all the way around. Sitting the barrel an extra 0.001 or 0.002" back into the receiver from lapping shouldn't be enough to create a pressure issue if a go gauge chambered OK and the round couldn't close on a no-go gauge right?
Stuff used:
New PF chambered Criterion 1:8. BCM upper receiver.
Tried N133, IMR4895, A2520, AR Comp, and CFE223, got early pressure signs in all of them near the published minimum loads.
Hornady brass (4-5 firings each), CCI SRP, Hornady 123gr ELD-M
Stuff I ruled out:
Neck "tension" was about 0.001 and all brass was just trimmed to 0.001-0.004 above published trim length. After running through full length sizing die, I tried to run a .262 mandrel through the neck but the neck was already bigger than the mandrel. I know too much neck tension or long necks can also cause somewhat intermittent pressure issues and think this can rule it out.
I know you can't directly compare barrels and I won't say I didn't make a different mistake in the process - I used the same reloading process as my old 6.5G barrel (along with other cartridges). Was able to go to published max using 4/5 of the above powders with no pressure signs at all. The 5th got about 3/4 of the way up the ladder.
Scale was working properly - other loads were loading before and after loading these rounds and they all gave expected velocities and had no pressure signs (as expected per their loads) in their respective rifles. Primers from the same batch were used as well in some of these rounds without issue.
