JR Carbine with Troy Alpha Rail

[Cammy7s]

My JR Carbine build project


Parts:
Magpul grip, foregrip, buttstock
15” Troy Alpha Rail
Standard AR15 Barrel nut
AR15 Carry Handle with rear sight
Quick detach sling mounts
LMT front sight
Washer/spacer/shim for barrel nut

There were a few things that had to be altered
1. Remove factory JR handguard and barrel nut with JR Carbine tool. I had to buy a standard AR15 barrel nut.
2. Install 15” Troy Alpha Rail
First of all you will have to remove the tab on the rear of the Troy rail as it will not line up properly with the JR Carbine receiver. The AR15 reciever that the Troy Rail was made for is a different shape than the the JR Carbine receiver.

Next you will have to either buy a spacer or shim for the barrel nut– see pic below. Without the spacer the barrel nut does not tighten all the way and the barrel will be loose. I used a washer from the hardware store that was close in size and filed/drilled them down to get the desired thickness and inner/out diameter.

C.The Freefloat Alpha rail uses the barrel nut to secure itself the the gun so the barrel nut must be lined up perfectly. After sliding the rail over the barrel nut you rotate it a few degrees and lock it in place.

What a great little rifle!

 

[speedjunkiesracing]

Thanks just got a 9mm JR Carbine cheap. Rail is on the way.

 

[Sniper1]

Nice setup. But your front sight is on backwards. flip it over and it will look much better !

 

[P0WERWAGON]

if you dont want to file, get a engine oil drain plug gasket for a 99 VW passat 1.8L engine. perfect fit and is a crush washer.

 

[Chairs]

Thanks for sharing this build! Been on the fence about buying one of these but I think gonna have to pick one of these up now.

 

[curseyou]

I would consider one in .45 ACP, but I'm wondering what the velocity would be out of a 19" barrel.

 

[ted_dent]

if you dont want to file, get a engine oil drain plug gasket for a 99 VW passat 1.8L engine. perfect fit and is a crush washer.

How the hell did you ever come up with this?

 

[pavmentsurfer]

That look amazing. Definitely a HUGE upgrade for the JR

 

[maurice]

will all rails require special fitting to work on the JR?
Anyone played with the buffer system? ie: gone to a heavier buffer?

 

[P0WERWAGON]

almost all AR rails will need a spacer between the rail and the receiver to take up the slack so there is tension on the rail.

what is the reason to change the buffer? it is a blowback design, no need to mess with the no existent gas system

 

[S1icedBread]

Will any handguard fit on this rifle? Or do i need to buy a special barrel nut?

Say I wanted to get a 15" DD from wolverine supplies, what would I need to install it? Aside from the volkswagen spacer...

 

[P0WERWAGON]

You need to use the barrel nut that the forend needs. Either the original ar nut or the proprietary one needed by the rail.