Advice - 11.5 in, suppressor-under-the-rail build

[User_name]

I've settled on a lot of things for my build, but I'm wondering if anyone else has looked into running a dedicated can on their SBR under the railed handguard.

Specifically, I've settled on an 11.5 in BCM government-profile barrel. I want to free-float handguards over it, and I'll be permanently running a Gemtech M4-02 on it. The Gemtech has a diameter of 1.37in.

I'd like to find a 12 or ideally 13 inch free-float handguard that's big enough on the inside that it will run over the Gemtech. I know people do this routinely with pistol suppressors, I've just never seen a picture of it done with a 5.56 suppressor.

Has anyone else done this? Ideas?

Any advice would be appreciated, and Merry Christmas.

[rob_s]

You don't see it as often with 5.56 cans because the OD is larger than the ID of most rail systems. This chart (http://spreadsheets.google.com/pub?key=pwswheghNQsFnUZMkZNF2DQ&output=html) may help you figure out which rails have an ID that you can work with.

The fact that you are using the M4-02 will help in your selection though. Most 5.56 cans are 1.50" OD compared to the 1.37" of the M4-02.

[User_name]

That chart is an awesome resource, thanks!

[ballistic]

Grant has already done all of the heavy lifting for you with his similar setup:

http://www.m4carbine.net/showthread.php?t=33558

http://www.m4carbine.net/showthread.php?p=402940#post402940

[crossgun]

Only word of caution I can throw is be a little careful with the spec posted in rob's chart with regard to the Troy TRX and Viking TRX Extreme rails. I am really starting to like the Viking VTAC version and purchased one for a suppressed 9mm build. Using a TROS 5" barrel with a 1.375 dia. SWR Trident can I thought I would be in high cotton!

While rob's ID dimensions for these models is correct what I believe he may have missed is the fact that that ID is only held for about the first 3 inches. DAMN! I can't get you an accurate ID beyond that but I do know it’s less than 1.375. My VTAC will be heading for the boring bar in the next day or two so I will report back once I can get an accurate ID. It appears to be the same on both the Troy and VTAC seeing I have both on hand.

I guess in your configuration in may not be an issue seeing not much of the can would be in tucked in behind the rail. The TRX Extreme rails are available in a 13" length as well which may just be the ticket.

Looking forward to seeing some pics of your final build.

[rob_s]

Good info CG, let me know what you find in terms of the reduced area and I'll add a footnote to the chart.

[rrpederson]

those threads that grant made are incredible. extremely informative on the suppressed weapon subject. i had to do a little bit of that type of troubleshooting on my own suppressed gun. the only thing that i dont have to reduce the recoil is a barrel with a smaller gas port, which may be on the way soon. i will have to go through the process all over again.

for the op-there may be times when u will want to take the can off. for example, for suppressing fire. the noise is just as important as the bullets in that situation i think. but to each his own. good luck with the build. i hope it turns out exactly the way u want it.

richie

[Todd.K]

Is this for the look or do you plan to grip out over the silencer?

A silencer gets real hot real fast on a 5.56 SBR, that heat is going to soak through the handguard.

[User_name]

Is this for the look or do you plan to grip out over the silencer?

A silencer gets real hot real fast on a 5.56 SBR, that heat is going to soak through the handguard.

The purpose is so that I can get as far out a grip as possible. I know I'm not going to be able to grip over the can, but getting the light and the iron sight out over it gives me more room behind. The only concern I have in that area is if my light overheats.

[User_name]

Pics of the almost final build:

http://i13.photobucket.com/albums/a273/IANALY/Iphone001.jpg

And in comparison to a regular 16 inch carbine:

http://i13.photobucket.com/albums/a273/IANALY/SBR2.jpg

Now to see how much it burns me up.

(and yes, I know the AFG is backwards, I think I like it better that way...)