Check out S.I.R I know they stock them but they are expensive ($29 ish for 20 rounds)
My Brother just shoot a moose at 140 +/- yards with his Rem 700 VSF (.308 with 180's ) and Broke his neck, instant kill, needless to say "no bullet recovery". This gun for some reason loves the MRX no B.S. this gun shoots 3 rounds into .235" at 100 yards!!!
The MRX really need to jump to the lands. Dont' even bother trying
.005"-.025", try .050" - .075" maybe even more????? Don't ask me why but damn do they shoot!!!
I would say, try a box and if they shoot better than your TSX then get them, if not stick with the TSX's
Hope this helps
Later
apapro