Rifle length handguard on an AR carbine.

[malinky]

I have a Bushmaster XM-15 E2 with a 16" barrel and a v notched gas block. I've been thinking about putting a rifle length handguard on it and was wondering how I would go about fitting a front sight. Will the gas block be okay under the heat shield of a longer handguard and will fitting from sights closer to the muzzle effect accuracy. Thanks in advance.

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[iamme]

As long as the rail is installed right in essence you can give your self a longer sight radius, good thing. I don't know what a v-notched gasblock is but not all lo-profile blocks will fit under all rails. FWIW- I believe I only currently have 1 AR15 without the gasblock under the handguard

 

[malinky]

Good information, thanks the XM15 is fitted with a gas block that looks a lot like a cut down A2 front post sight.

 

[iamme]

Only thing I can add is make sure you can attach your GB with the rail you're using. I prefer Apex and similiar that clamp to factory nut as they're easy to remove for GB work, etc.

 

[Nwcid]

For fitting the front site you need to make sure you get the right one. There are 2 different styles. One stile is for mounting to railed gas blocks and one for mounting to railed handguards. They are different heights so if you have the wrong one you will never be able to get a zero.

The gas block will be just fine under a handguard. Just make sure you get a block that will fit under the handguard you use.

 

[bmgm37]

Are you wanting to put a rail or rifle length handguards? If you want a rail, you just need to fins a free float one that will fit over the gas block. If you want rifle length handguards then you could install a dummy front sight base. This is how the original Dissapator uppers from Bushmaster were done. Bushmaster drilled and pinned the FSB on like normal but you could just get one that fits the diameter of your barrel and setscrews on. You would have to also install a handguard endcap and it is just loose and spins as there is no gas tube to hold it but when you install the handguards it locks everything in place. Here are pics of mine.

 

[deadshot2]

Bushmaster did this with their Disapator barrel. Have one and it shoots great. Heavy barrel with long sight radius. I just put a free float "tube" on mine. Not real "sexy" but it gets the job done. I changed out the front sight for a rail type gas block (I just don't use the gas port in the block) and have a MI flip up sight on it. Matching sight on the upper receiver rail for use if I bash the scope.

 

[malinky]

Are you wanting to put a rail or rifle length handguards? If you want a rail, you just need to fins a free float one that will fit over the gas block. If you want rifle length handguards then you could install a dummy front sight base. This is how the original Dissapator uppers from Bushmaster were done. Bushmaster drilled and pinned the FSB on like normal but you could just get one that fits the diameter of your barrel and setscrews on. You would have to also install a handguard endcap and it is just loose and spins as there is no gas tube to hold it but when you install the handguards it locks everything in place. Here are pics of mine.

Thanks this is the same setup I have and the same handguard I want to put in it.