Has anyone recrowned their SVT 40 ? if so what tool did you use, ive been looking at 11 degree recrowning tools at Midway and Brownwells, but im not sure of the effects an 11 degree face on the crown may have in conjunction with the guns muzzle brake ? Also would the pilot bore be .311 ? and is .311 the same for 7.62x39 as well (the crown on my SKS rifle could be better) would re crowning have a negative effect on the chrome lining ?