I'm looking at "building" a 6.5CM AR10 with the intent of shooting no less than 1k yards. I'd choose a bigger cartridge if it'd fit, but anyway... 114 changes things. I want this sucker to be heavy to suck up any recoil the already pipsqueak 6.5 produces. What I've found for options are a 24" heavy profile BA barrel, likely using my sandman L on front and a Magpul PRS at the back. From there, I'm not sure how to get more weight than standard AR10s. Quad rail? Steel inserts? I'm open to suggestions.