Dry fire and rim fire need a-zoom ... - A-Zoom Rimfire Action Proving Dummy Rounds

First time rating a product on Optics Planet. I shoot about 10,000 rounds of rimfire per year +/- a few thousand as well as dry fire at least another 4,000 or 5,000 per year what with cleaning, tinkering, upgrades and working on trigger control. Been doing that for about 25 years - some more, some less. This year I've been doing a bunch more dry fire, for obvious reasons and have really spent some time looking at snap caps.

In the world of centerfire snap caps (which I also use) the differences matter a bit less depending on what you want to do. However, with rimfire snap caps, after trying about every brand I could find out there I have come down to only 2 and A-Zoom is one of them. I no longer use the hard polymer snap caps any more because with some of my rimfire weapons the firing pin spring is strong enough, and firing pin itself is punch style, they won't last more than a few hits and will fracture.

The A-Zoom caps have fit dimensions that are very consistent. I've done function testing from magazines and with revolvers - and specifically here with a CZ452 bolt in .17 HMR. Without question, any rim fire snap cap will get damaged from the firing pin, and the A-Zoom will as well. However, in comparison to other brands these seem to represent the best balance of durability and utility. I've tried steel snap caps which are more durable, but the brands I've tried haven't been as consistent dimensionally, and I'm not confident that the hardness of all firing pins are compatible. No question with the A-Zoom.

The A-Zooms will last a surprisingly long time - the rims get peened by the firing pins without question - which actually has allowed me to do light strike testing for firing pin springs when not at the range. I probably get a hundred or more hits on them, particularly with rotating them in the magazines. Until someone comes up with a better design with higher reusability - these are about the best I've found.