Not a seasoned reloader. Have a chance to buy some primers and want to know if size is equivalent to what I've been using. Currently using cci large 300 pistol primers. What is avaliable is remington large 2 1/2 pistol primers. Good to go or not.
While back I ran into some online primers from nonfamiliar makers. With online reviews I received same information you post about seating.One word of caution, you likely will not run into it with pistol primers. Rifle primers it happens a little more often. Buttttt
The sizes are all standard, but some are a little more standard than others. You'll get them all to fit, 100%. But a combination of different cup thickness and hardness can change how easily they seat, as well as how easily they can be set off.
Additionally, some manufacturers, mostly foreign (not all foreign, just where you'll find it more) are not exactly the same dimensions. Basically they'll work, but it'll be a tight fit and take a fair amount of extra force to seat. Which can be good for brass with loose pockets.
I am not aware of anyone's pistol primers where that is an issue or concern. Probably in part because pistol primers already have thinner cups than rifle primers, so they'll be easier to seat.
Just a friendly reminder when switching primers to work your load back up. Especially if you are running near the bleeding edge of pressure. If you are at a much more moderate or low pressure than you'll almost certainly be fine, but you might still find accuracy changes a bunch or something and you need to tweak things.