Fellas, the OP is referring to "Musket Caps" …..
tranders
I have used these as well as others and I honestly can't say that any of them have given me, any issues. Must caps can become contaminated as opposed to primers. …..
If you want to compare any cap, there is a way to do it but you have to define a standard, Like the RWS's or whatever you currently have faith in. ….
Be Safe !!!