There are many thick books dedicated only to the subject of gunsmithing the 1911. It takes hundreds of technically descriptive pages to explain the total workings of one. It is the most complex, yet elegantly simple and efficient devices I've ever seen.
The inertia firing pin in 1911's can leave some funny looking primers on firing if the primer cup isn't 'balanced' as to thickness hardness material, etc. Pin weight, spring tension, even mainspring are part of the balance. I would eliminate the primer brand first if it were me.
Before I even owned a 1911 .45 I shot my Dad's. The club had got some DCM .45 military ammo for our qualifications and the batch brought a lot of raised eyebrows! (before Botox) It was steel cased! It was headstamped "E C 43". It shot OK. Some tried to reload the steel case and couldn't. The primers were small...... Now I don't mean small pistol.... I mean .005" or so smaller than large pistol! Not only that..... they appeared to be copper or copper plated steel??. At any rate, the 1911's left them looking different on fired cases...... Most had the dent lessened; some almost looked unfired with the dent pushed back flush! Then some crated to some extent like Brad's. Not all of the 1911's reacted.... but most did! I think pressures were fine just the inertia pin went goofy over those particular primers. For this reason I'd be careful with the 1911 and the fired primer appearance unless other American brands also displayed the problem.
Those were EVANSVILLE Cartridge Company, we made 95% of the .45 cartridges used in WWII. I have some snake loads from them. Paper folded over #9(?) shot to look like a regular ball round. Supposedly issued to troops in Pacific, load by hand in chamber for first shot, load clip of ball as usual. Paper would shred and empty case would eject. No loading from magazine!
I shot a lot of steel cased .45 ACP in a friend's Colt 1917 Army when I was a teen. It was $1 per 100,
so we loved shooting that old girl...although it was corrosive. Yes, I remember the copper colored
primers in the zinc washed cases. The undamaged bullets, dug from his sand berm were set on their
bases on a board and we use them as targets at about 20-25 yds sitting with .22 rifles. The .22 bullet would
split the jacket, expand and weld to the lead core, the whole mess stayed intact. Somewhere I have a couple
I have some Evansville brass .45 ACP WW2 in original box, too. Decided not to shoot it, just keep for it's
sentimental value. Must have been a big arsenal.
I can assure you that Brad's primer appearance is not normal. The only 1911 brass that I have seen like
that in more than 30 years of picking up 45 ACP brass at matches, was .38 Super, a good bit of it not mine, I have
never seen even one like it in .45 ACP. A good number of them in .38 Super looked like that when people were
first pushing for Major Caliber and hadn't yet figured out how to safely do it.
Something is off kilter, seeming to be high pressure, but that assumes normal primer cup hardness
and thickness, which may or may not be true.
Back to changing brand of primers as the leading candidate as "next reasonable step".