Do these cases look like excess pressure?

[pomofo]

When I first started loading for the Grendel 15 years ago I never paid much attention to brass case head signs with regard to pressure since I assumed Alexander Arms' data was within safe limits. But my factory AA upper seems to have been overgassed from the start, and I remember a decade ago noticing that some of my fired brass seemed to have primer holes that were opening up, so this time around I've worked up loads more thoroughly, paid more attention to what the brass has looked like, and have used heavier buffers to slow unlocking until chamber pressures are lower.

With that being said, do any of these cases look like they're problematic? Or to put it another way, if you saw this brass, would you assume something might be wrong? This is the second firing for these pieces. Once-fired loaded round is on the left for comparison.

[grayfox]

There are more expert guys on here than me...
Did you run any of these over a chrono?
What powder loads and bullets were shot? Lots of details left out.
How much shoulder forward-movement/setback happens with these loads in your chamber, and resizing?

3-5 and 7 look like they have some extractor digs/roughing on the rims, 6-7 look like they have some ejector marks on the bases...

To me they look like they've been "rode hard, put up wet" somewhat -- could be from overgassing still or something else, idk.

The best way to determine any of this is to shoot ladders and loads over a chrony to track MV's and known loads or book values. Everything else is going to be guesswork more or less.

[LR1955]

Look fine to me.

Gas operated rifles tend to be tough on brass so the nicks are part of the game to me.

Big thing is flattened primers and ejector swipes. I see none on any of these pieces of fired brass.

I see no problems.

LR-55

[empTshell]

Look fine to me.

[pomofo]

Good to know. I left out details because I didn't want that influencing and prejudicing opinions.

These were fired with 123-grain Lapua Scenar bullets using Alexander Arms' 2006 load data. Powder was Accurate 2520, purchased in 2009 and opened a month ago. The three cases on the left were fired with 30.4 grains, averaged 2447 fps. The three on the right were fired with 30.7 grains (max load), averaged 2490 fps. 16" barrel, midlength gas.

Buffer is an A5H3 into which I swapped another tungsten weight to get the weight up to ~6.7 oz. Ejector swipes seemed to dissipate with the heavier buffer, so I'm in the process of machining a stainless steel buffer to get one even heavier and see if I can get them to disappear completely and still function the rifle.

[Klem]

Mofo,

That is a hot load at 108% compressed. Not much point commenting on what those cases look like because when they show signs of overpressure, in an AR, it's too late. A heavier buffer taming all that excess gas will give a false sense of security because peak pressure occurs before cycling.

[Zeneffect]

I will say, I see a circular ejector mark. Based on charge weight, and knowing the bearing surface of lapua projectiles is normally longer than say a berger or hornady you are over pressure on the 30.7 in my opinion. 30.4 is probably where I would settle as that .3 isnt gaining you much utility at 43fps. If you want more speed, get a different bullet, not more powder.

Klem,

Ball powders, compressed isnt necessarily bad. lvr + 108 - 110% quickload = friggin MAGIC on everything I have tried. I am 100% sure it isnt 110% compressed and QL has kernel size too big.

[ported45]

Looks to me that the 3 to the right have ejector extrusion.

[LRRPF52]

Good to know. I left out details because I didn't want that influencing and prejudicing opinions.

These were fired with 123-grain Lapua Scenar bullets using Alexander Arms' 2006 load data. Powder was Accurate 2520, purchased in 2009 and opened a month ago. The three cases on the left were fired with 30.4 grains, averaged 2447 fps. The three on the right were fired with 30.7 grains (max load), averaged 2490 fps. 16" barrel, midlength gas.

Buffer is an A5H3 into which I swapped another tungsten weight to get the weight up to ~6.7 oz. Ejector swipes seemed to dissipate with the heavier buffer, so I'm in the process of machining a stainless steel buffer to get one even heavier and see if I can get them to disappear completely and still function the rifle.