gregrn43
I have a White M97 U-Mag and the 209 breech plug is all I shoot from it. There certainly is some blow back from the powder charge but I do not think it is that much more than a #11 breech plug.
Cayugad is correct you will probably need a different hammer also as you need a pin in the end of the hammer.
I think if you shoot a White, and I am not all that familiar with the G series you are going to need some sort of scope protection if you are mounting a scope.
I just wrap mine is a camo cloth and it works just fine...
