Tested my baby for function today . Fed fine , ejected fine , and locked back on last round . The pistol is working fine . Here is my problem . I have two cases from my test loads that concern me ( fired three but lost one case ) pictured below .
These loads are LC brass trimmed to 1.358 , 17.6 gr. AA 9 , CCI 450 , topped with a 110 varmageddon at 2.06 coal . I think they are a little too hot . Any comments . Thanks .
The only thing I'd mention is that your primers look kinda flat. It's not like blow-your-gun-up flat, but I wouldn't load any hotter if I saw those primers on my spent cases. perhaps I'm overly cautious, but I don't have technical info as to how flat is too flat.
This is what you're looking for...when the gap or channel between primer and brass becomes a fine line, and you start to see a 'raised ring' around where the primer is struck. This is an extreme example - signs and symptoms of overpressure should be obvious prior to seeing anything remotely close to this. Your primers look fine to me.
The one on the left has a very minor ejector swipe - that's a bit hot, but as was said, not "Oh my god, that was close" hot or even remotely in that territory. But you are at the upper limit of what's considered safe. "Safe" by the way, accounts for some temperature variations. When you shoot a safe load in the cold or extreme heat, it's still not going to cross over into "kaboom" dangerous. If you were getting a solid extractor swipe (brass bulged out into the ejector hole), and the cratered primers as shown above this post - then you changed an environmental factor (extreme hot or cold - depends on the powder in use), you might end up with excessive chamber pressure and a real problem.
The one on the right only has primer flattening. Primer cups are pretty soft compared to the case head (some brands are softer than others too). You can get a nice flat primer and not be in any danger of over pressure. When the margins around the case head start shrinking, and you're flowing primers into that area, then you're starting to get a bit too hot.
I also want to add, you can get a cratered primer with excess head space and not have over-pressure. I've had a couple 9mm's that did this and it was due to the chamber being over cut. It's certainly not that common on rifles though.
You can also mushroom primers with improperly sized brass if the shoulder has been set back too far. The case slams forward from the firing pin force, then the pressure builds and the primer backs out, then the pressure builds higher and the case is forced back against the bolt face causing the primer to moosh into the cavity created by the primer pocket radius.
I would agree with the other comments.
The load is right at the limit of what I would be comfortable with.
If it were me, I would back your load down 2/10ths of a grain and rock on.
"Don't tell fish stories where the people know you; but particularly,
don't tell them where they know the fish."
--Mark Twain
Looks normal "max" to me. The one on the left has some light ejector marks and the one on the right looks like it has a very light ejector mark at 8 o'clock. Primers look ok. I don't see much if any deformation. I wouldn't necessarily go lower unless the grouping was bad. I wouldn't go higher either. That's just me. Here is an example of to much:
