I got a dodgy mk23 barrel (right hooking shots) off them once. I ended up having to ring them. Spoke to me like I was the issue. You literally can't put a mk23 barrel in wrong an shot straight again when returning to the original barrel which I did a couple of times to be sure. Had to push a little to return, and have the post plus the post it cost me to return as I wasn't gonna be £5 out of pocket for them sending me a flawed barrel. Even then had to poke them for my refund after they had received it. It wasn't great but I got my money back eventually.