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I can't say without a doubt but it should, I run a Jp adjustable block under one of fine and it clears that fine. The handguard that I use to run with that block was a MWI and it clears the superlative thats under it now. You should be fine.
It does. I just put 2 15" mk16 on builds using SA gas blocks. All are .750" fwiw. The .750" SA GB fits under the mk14 too (a few of them in the safe). As mentioned above, set screw versions.
however, the MK16 (or any of the geissel rails with the 4 anti rotation tabs) does NOT fit with a larue stealth upper receiver. Even though both claim to be "mil-spec"
I was super pissed. Then I realized I could use that rail on another project and ordered a forward controls rail and that should fit.
Maybe I should clarify my earlier post. The .750" SA set screw GB will fit under the mk14 and mk16 but the handguards may not work on all uppers. I have run into both rails not fitting "thick" uppers to include a CMT I just installed a mk16 on last week. A small amount of measurements and application of a fine file and it fits fine. Some may not want to use a file on a $$$ handguard but me and aluminum black liquid have a long history.
Looking at the Larue above, yeah that won't fit. I bet it did piss you off.