Rolling block problem!

[Procrastinator]

I picked up a Uberti Rolling Block Carbine in .22 Hornet at a recent gun show.
Took it to the range this week and the primers are being set back .015 (one pierced) when it is shot.
Any suggestions, comments or help in solving this problem?
Is it possible that the firing pin is too long and is igniting the primer before the hammer contacts the block?
Any and all help appreciated.

[Rollershooter]

It is possible that you were shooting ammo loaded with PISTOP primers. They are a little shorter than rifle primers, and will set back upon firing. This in time can damage the breech block as well as result in pierced primers.