I have had a 5.6x57mm for almost 10 years now. It is actually the second barrel on a switch barrel custom rifle I had built on a Argentine 1009 action, the first barrel being a 7x57mm. I wanted to use the gun to shoot coyote and wild dogs on our family land. I had the barrel built with a 1/10 twist and it shot the factory 72gr RWS fairly well. Shortly after having the gun built it bacame very difficult to find the RWS ammo so I handloaded some very accurate rounds with 55gr sierras that cronographed around 4000 fps. Its been few years since i've had the barrel on the gun and I never shot anything with it but paper but I like the hot little round.

Jeff