Re: 6mmppc and 6mmbr
Yes I have a 6BR based on a Rem700 that I use mainly for varmint hunting, but I have used it on New Zealand feral goats (a major pest!), some of which would easily be 50 lbs. Longest kills on Rabbits so far has been 400 yards & and goats 200 yards.
Both the 6PPC and 6BR are extremely accurate. For any given bullet weight you can probably expect approx 150 fps greater velocity with the BR compared to the PPC. And the 6BR has the advantage of using the same bolt face as the .308 win. Iím currently achieving 2990 fps with 87grain V-max bullets from a 27 inch barrel (1:10 twist) burning 31 grains of Varget (ADI AR2208). I have tried Berger VLD 95 grain projectiles (BC of 0.51) but a 1:9 twist is required to stabilise these at/near sea-level). I shoot my 6BR single shot. But modifications can be done to allow feeding from a magazine.
The website 6mmBR.com has a wealth of information on this and similar cartridges.