Some observations. I've gone through a few thousand primers ea of Federal, CCI, Murom, Remington, and Winchester in the past 8 months. A combination of NOS and new production. Combination of small and large in each. All of this on new starline or armscor brass.
The most consistently easy to seat and perform are Federal, both NOS and NP. These have the softest cup as well. Zero FTF's with any federal pistol primer. No matter how net ninja'd a gun is with dumb trigger work, or how lightened a hammer might be....seems it will go bang with federals. Cons: tiny bit smaller, and once in a while they flip in the primer tube. I get 2 or 3 rounds per 1000 with federal with an upside down primer because of that. And we all hate that stupid box. More federal primers have hit the floor in my shop than any other brand, lol.
Remington: The have a slightly harder cup than Federal, but still softer than CCI. They seem to be generally good, and I don't get any flipped primers in the tubes. Every once in a while I get one that is harder to seat. Rarely, it seems that some super light weight DAO revolvers light strike these. Very very rare though, and my thought is that it correlates to the ones that are "hard to seat", but have no hard data to support that.
Murom (Russian), ok, oddly enough....these are flat out the most consistent and accurate primers I've used in large pistol. However, they are HARD to seat on new brass, real hard...and the cups are hard, waaaayyyy to hard. So while shooting strings of 45 Colt or 44 Mag out of big SA revolvers may result in undeniably better SD's when the only change is primers....I don't use them anymore. I have a much higher percentage of light strikes on these with any striker fired pistol (Glocks, Croation Glocks, etc), as high as 2/100. And DAO revolvers and SA revolvers with hammer/trigger work really have a high percentage of light strikes.
CCI: CCI are probably overall the most dependable primers. They seat well, they are the "right" size, consistent, they work perfectly in tubes and collaters, just all around easy to work with. The only con is that out of all the US primers, they seem to have the hardest cups. And while they are nowhere near the level of hardness of Russian (or any euro) primer, they still will on very very rare occasions cause a light strike on a very tiny minority of guns. All but one I know of personally had trigger/hammer work done, and I blame the net ninjas, not the primers. The one factory gun I know of that had issues was a Taurus titanium airweight 38 spl. I don't know if it was just the one gun, or if that particular model may have a problem with harder primers across the board.
Winchester: My least favorite US Primer. Just seem a bit inconsistent across the spectrum. I've always avoided them when possible, but will use them if I have too. They seem to go bang consistently, but they tend to have more issues with primer feed systems.
