I have a stock Bushmaster XM15-E2S AR-15/M4.. I'll be the first to say that i'm no pro when it comes to AR-15's, as this is my very first.. I have been doing a bunch of research and I have pretty much boiled it down to the Troy BattleRail 12" since my Bushmaster has the front sight and I like the longer rails for the 16" barrel. Anyways, I noticed my Bushmaster has a sling mount thing under the front sight, and my question is.. With the Troy BattleRail MRF 12" rail, will this be a problem?? I plan on attaching a sling as well and I am not sure if the rail either comes with an attachment itself, or if there is like a hole for the Bushmaster sling mount to go through.. Sorry if some of my "terminology" isn't accurate, like I said i'm new to this AR stuff.. Any help would be appreciated.. Thanks guys!

Bought mine in '98 and have a 14.5" barrel. Pinned flash hider.

Aren't all or at least most of the Bushmaster lowers marked XM15-E2S?

EDIT: Too many XM15-E2S configurations to help without a picture of your rifle.

OP, your rifle probably has carbine length handguards. The Troy MRF 12" raill will not work as is since it's designed for a rifle length AR. To use it, you'd have to chop the front sight and sling swivel and do a bit of shaving to convert it into a low profile gas block. Then you can use that rail though you might have to have the work done at a gunsmith if you can't slip the rail/hardware over the flash hider.

Another solution is to use a different rail that is two piece and goes around the front sight and still gives you some more rail space in front of it, something like the Centurion Arms C4 Rail System FSP 12in. This rail has QD swivel buckets on the front and rear on both sides to attach a sling. You might still have to remove the stock sling swivel and shave the the underside of the stock front sight post to clear the rail.