I have one in my safe at the moment - 7mm, 8.5 left hand twist, 4 groove finished at 32". It's chambered in 284 Shehane and has done over 2500 rounds and it still shooting lights out. It takes a good 7-8 shots to settle down after being cleaned back to bare metal, but it's probably the most accurate barrel I've had. My gunsmith took a look down the tube recently and aside from the usual wear around the lands, the rest of the barrel looks Mickey Mouse, it's like nothing he has seen previously so I put that down to the steel. I do have another on order.