Murray, thanks for the info its been very helpfulThis is , I believe , what the Sako chambers are.
I agree. The USA chamber on my Sako wants a heavier (longer) bullet than the twist of barrel will spin adequately - but it still shoots.PPC-USA?
I do not know the freebore but I think the Sako PPC factory guns were all PPC-USA and a diagram should tell you.
If you are using a PPC-USA then either brass will work. I have used both on 22 and 6 PPC-USA.
If the reamer is a USA spec then you can also locate some PPC USA brass.
Maybe all this is way off base but I thought it MIGHT help.