Vince
I guess you would have to ask the guys shooting free recoil how they get on with the heavier hitters in regards to calibre.
Just stay away from the Jewel triggers if you fancy trying it.
Another vote for Reloading Solutions and Brian Fox. The boys at Rodding Armoury are handy to know as well.
Tim Hannams
Zeiss UK
Optics warehouse
Uttings
Have all given sterling service in the past.
I just wish they sold at US prices.