Bought an 84M Varmint .204 with the intention of rebarreling to 1:7 223Rem and dropping it into a spare a Montana stock. Issued mag-box is 2.275-ish. What's the best way to get it to 2.5"-2.6"ish? Cut the spacer out and shorten it or??? The bolt stop and ejector are fairly self-explanatory, just wondering the easiest way to get the mag-box right.