Troy rail help needed

[deuce9166]

Guys I installed a 10" Troy MRF on my 14.5" (Perm. attached FH) yesterday and while zeroing my irons I noticed a poi shift. I knew something was loose and sure enough I grabbed the rail and could rotate it a little. The allen screws are still tight. I shoot irons alot and this would be a definate problem. Any input would be appreciated.

Thanks,
D

[Robb Jensen]

If the screws are tight and the rail is still moving, the barrel nut may be moving too.

I recently saw this scenario with a LWRC (an early one) and their rail. It required a new barrel nut and proper torquing. I have no idea how it came lose other than maybe it wasn't torqued the proper three times before final torque or what.

[deuce9166]

Thanks for the fast reply. I'll check it right now.

[deuce9166]

M4, beers on me!

Tightened barrel nut and the rail seems rock solid now. Thanks for your help, you salvaged my weekend. After spending all afternoon grinding the fsb and trying to watch twin boys I spaced on the brl nut.

Thanks again,

D

[LMTRocks]

I had the exact same problem installing the MRF-R 12" rail on my LMT upper. Solution? Get some brass and cut some "shims/strips" to fit in the barrel nut channel and a couple to go under the gas tube and over the barrel nut. When the rail was level with the upper receiver it would shift a little bit and I'm not the only person with this issue. I talked with Chris at Addax and he'd had issues with the Troy MRF floating rails having fitting issues. I guess Troy needs to address their "anti-rotation" lugs to fit uppers better (they're loose by perhaps 1/32" on each side) because if I torque the clamping mechanism down to keep the rail level with the upper receiver it will twist to either side. If I clamp them down tight to where it won't twist, it's perhaps 1/16" low. You'll need a little patience in cutting metal to fit in the barrel nut channel and it might make the rail "tilt up" at the muzzle end, and the solution is to "shim" that up with some strips so that it levels out. Personally I won't put another Troy MRF floating rail on any of my weapons until I hear they're in spec well enough that doesn't require me doing additional work.

[Iraqgunz]

Have you bothered to contact Troy to address the issue? The use of shims is the not the solution and the rail needs to be installed and fit correctly.

You can't expect Troy to address the issue if no one contacts them.

I had the exact same problem installing the MRF-R 12" rail on my LMT upper. Solution? Get some brass and cut some "shims/strips" to fit in the barrel nut channel and a couple to go under the gas tube and over the barrel nut. When the rail was level with the upper receiver it would shift a little bit and I'm not the only person with this issue. I talked with Chris at Addax and he'd had issues with the Troy MRF floating rails having fitting issues. I guess Troy needs to address their "anti-rotation" lugs to fit uppers better (they're loose by perhaps 1/32" on each side) because if I torque the clamping mechanism down to keep the rail level with the upper receiver it will twist to either side. If I clamp them down tight to where it won't twist, it's perhaps 1/16" low. You'll need a little patience in cutting metal to fit in the barrel nut channel and it might make the rail "tilt up" at the muzzle end, and the solution is to "shim" that up with some strips so that it levels out. Personally I won't put another Troy MRF floating rail on any of my weapons until I hear they're in spec well enough that doesn't require me doing additional work.

[MisterWilson]

Have you bothered to contact Troy to address the issue? The use of shims is the not the solution and the rail needs to be installed and fit correctly.

You can't expect Troy to address the issue if no one contacts them.

Don't listen to IG. What you REALLY need to do is break out the dremel...

[rockm4]

I had the exact same problem installing the MRF-R 12" rail on my LMT upper. Solution? Get some brass and cut some "shims/strips" to fit in the barrel nut channel and a couple to go under the gas tube and over the barrel nut. When the rail was level with the upper receiver it would shift a little bit and I'm not the only person with this issue. I talked with Chris at Addax and he'd had issues with the Troy MRF floating rails having fitting issues. I guess Troy needs to address their "anti-rotation" lugs to fit uppers better (they're loose by perhaps 1/32" on each side) because if I torque the clamping mechanism down to keep the rail level with the upper receiver it will twist to either side. If I clamp them down tight to where it won't twist, it's perhaps 1/16" low. You'll need a little patience in cutting metal to fit in the barrel nut channel and it might make the rail "tilt up" at the muzzle end, and the solution is to "shim" that up with some strips so that it levels out. Personally I won't put another Troy MRF floating rail on any of my weapons until I hear they're in spec well enough that doesn't require me doing additional work.

Hello all, don't be so fast as to blame Troy, if you were to measure 10 different barrel nuts you will get 10 different readings it's normal. I've installed 6 Troy MRF rails with 0 problem. I would call Troy on this problem, they are super nice to deal with and will make it right. sometimes parts get out of spec. IG's right ! Don't try to jury rig something that's easily returnable for the correct part. You'll be cussing it long after it could have been corrected from the manfu. Patriot

[LMTRocks]

It's funny how I was quick to blame TROY regarding the MRF rails. I wasn't---I installed the same rail on two different guns and it exhibited the exact same problems. It seems that whenever I see a Troy MRF rail on any other gun (there are several around town with the same rail) that all of them are doing the same thing---they're low. Satire: Maybe Chris at Addax doesn't know what he's doing installing them and I don't know what I'm doing, but when my MRF-R rail went onto my LMT the first time it was low and did the exact same thing on my Alexander. Perhaps several armorers around town are having the same issue with that 1 type of rail system and we all just don't know what we're doing. Gosh we must be having back luck. I actually believe Chris at Addax is an excellent builder and he's getting my business soon as I get my LMT upper back from refinishing. I also offered a solution to a problem and was blamed for it. Sorry I didn't offer pictures. I just think cutting brass shims for the barrel nut channel was the solution that I've found success with, and Chris at Addax has contacted Troy and they did not give him any positive feedback. Sorry IG and RockM4---my shims work for me. I'm not cussing after I'm done working on it. I'm cussing at it for not working the way it says it will the first time. I'd rather fit the darn thing myself and have it perfect than having to send it back and forth at my expense wishing for a perfect union. Sorry for any trouble caused here. Code 10-03. End Rant.

[Iraqgunz]

You are missing the point. M4 Carbine has a set of rules that we try to adhere to. One of them is prior to bitching about xxxx doesn't work right and xxxx company is selling crap that you first contact the manufacturer to remedy the issue. As far as I can tell you didn't do that. Here is the link, 4th bullet down.

https://www.m4carbine.net/showthread.php?t=26452

YOU SHOULDN'T HAVE TO MAKE SHIMS to get it to fit properly. That is the point. It may turn out they they are out of spec in which case I am fairly confident they would want to know. There may be another issue that we are unaware of causing the problem. Whatever it is, it can't be fixed if no one takes action. Why don't you contact them directly and explain the issue. Then wait for a response and tell us what happens?

As for the shims. They may work great in the interim, but are they going to hold up?

It's funny how I was quick to blame TROY regarding the MRF rails. I wasn't---I installed the same rail on two different guns and it exhibited the exact same problems. It seems that whenever I see a Troy MRF rail on any other gun (there are several around town with the same rail) that all of them are doing the same thing---they're low. Satire: Maybe Chris at Addax doesn't know what he's doing installing them and I don't know what I'm doing, but when my MRF-R rail went onto my LMT the first time it was low and did the exact same thing on my Alexander. Perhaps several armorers around town are having the same issue with that 1 type of rail system and we all just don't know what we're doing. Gosh we must be having back luck. I actually believe Chris at Addax is an excellent builder and he's getting my business soon as I get my LMT upper back from refinishing. I also offered a solution to a problem and was blamed for it. Sorry I didn't offer pictures. I just think cutting brass shims for the barrel nut channel was the solution that I've found success with, and Chris at Addax has contacted Troy and they did not give him any positive feedback. Sorry IG and RockM4---my shims work for me. I'm not cussing after I'm done working on it. I'm cussing at it for not working the way it says it will the first time. I'd rather fit the darn thing myself and have it perfect than having to send it back and forth at my expense wishing for a perfect union. Sorry for any trouble caused here. Code 10-03. End Rant.