I’m going to pick up a Troy TRX rail soon, probably in the 13" length. The only local place that I’ve found that could do it quoted me $50 for the install, but extra if they had to shave the FSB and extra to install a new muzzle device (figured I’d knock it all out at once).
Knowing that, I figured I’d save that $50-100 and maintain my ability to say that I’m the only person that has ever worked on my rifle. Will the tools below do the job?
Bench vise, adjustable wrench to remove flash hider, punches to remove FSB, Troy’s included barrel nut wrench to remove favtory delta ring/barrel nut (and install their barrel nut), hacksaw and metal file to cut down FSB (and high temp paint to refinish it), plastic/wooden mallet to re-pin shaved FSB, and crush washer to reinstall new compensator.
You need a clamping fixture to hold the upper in the vice, and a block to hold the FSP to knock out the pins. I guess you could make both from wood or similar but you are rolling the dice as far as potential damage.
You also really need a torque wrench for both the barrel nut and the muzzle device, some people can do it by feel but they have installed enough of them to know the proper torque.
Don’tuse an adjustable wrench on your muzzle device, get a proper wrench.
Action block indeed. I’ve installed a ton of flash hiders with an open end adjustable. Too many variances in the sizes on flash hiders to us a standard wrench.
S.A.W. has a 3 slotted deal to accomodate the variety of flash hider sizes out there.
I’ve never done a cut down… do you NEED to remove the FSB? Couldn’t you just us the cut off wheels on your dremmel to cut it in place? (forget the hack saw) Oops… you have to change the barrel nut anyway… so you’re taking the FSB off no matter what. nevermind.
Thanks man, yeah I think I can get my hands on a torque wrench. Any ideas on the cheapest place to get a FSB pin block and the clamping fixture? I saw the pin block on Brownells but at $40 but that seems like a bit much for something I may never really use again.
I have that pin block, and it doesn’t work THAT great on tough pins. You could just bang them through on your vise if you’re cutting the FSB anyway.
You DEFINITELY want to get the right punch. We had to go buy a big nail set punch because they have the concave tip… makes a big difference. A flat tip punch will skip right off of the pins if they’re in there tight.
Awesome, thanks for all the help. It doesn’t sound too hard really. I’ll do some reading on indexing the compensator etc., I’ve got a couple things that have to sell before I get the ball rolling on this (like new Aimpoint ML2 will be for sale here before the end of the night). The upper is a BCM, so it should be fine to reuse the pins.
Oh, and does the gas tube just slide into the gas block or is there some sort of retainer holding it in place?
You can cut and grind the FSB in place. I just did one a couple of days ago. You should get an upper receiver block from Brownells otherwise something will go FUBAR.
If you don’t want to spend the money on the right tools, then send it off.
Remove the gas tube.
Using a Dremel cut and grind the FSB.
Remove the pins (I would soak them in Kroil or other lube).
Remove the barrel assembly.
Install the Troy barrel nut, torque appropriately.
Slide the rail over the gas block to ensure that it clears. You may need to do some more grinding.
Reinstall the gas tube.
If everything clears then slide the rail over and tighten the screws down.
You may still need a barrel nut wrench for the factory nut/delta ring. I bought a TRX in March from Troy. I opened it when I received it only to find that the included barrel nut tool was different from the pictured tools to where it only works on the Troy TRX barrel nut.
I do this as well. I have a snap-on punch that I put in the mill and ground down to 1/8" from where the taper starts. It’s short, and thick, so there is no dexterity or skipping around issues.
Once they are flush, they come right out with the correct sized punch.
If I leave the gas block in place, do I dremel off that front handguard cap that sits behind the FSB? I guess I also assumed the barrel nut/assembly wouldn’t fit over even a shaved FSB but if it will, that would definitely cut down on the difficulty.
