A couple things on primers for the triumph from my experience:

1) on some Triumphs Triple 7 primers are too long and will not allow the gun to close. I was shooting Black mag 3 w/ Remington Klean-Bore primers and got a bad crud ring. Switching to Remington SST (STS??) primers seemed to help.

2) IF you decide you want to use the Vari-Flame conversion kit (to alledgedly get rid of the crud ring by using regular small rifle primers) - I found that only 1 of the 10 adapters that came with the kit would allow the gun to close. They adapters were too long..

Brian