I should have researched these a bit more before I bought.  I wont ever buy another forearm that mounts to the factory barrel nut.  I think this is probably the cheesiest mounting solution I have ever seen.   I was going to get a 15 Geissele MkII but I was concerned about the weight and I let a few people convince me it cost too much.  So I went with a 15" Alpha.  I dont know if I will ever get it straight,  I just mocked it up with a different barrel while I am waiting for my 6.5G barrel to get here.  Anyone else share my feelings on the Troy Alpha rail?


UPDATE    

So it just so happened that sagmill, read this thread and took pitty on me.  He gifted me an SMR MKII 13" with I believe and this may be incorrect information here, the alloy barrel nut for the newer MK4 forend.  This happened around Christmas and I took FOREVER to write this because I wanted to do it with pics of my build.  However I have come to believe I will never receive the 6.5Grendel barrel I am waiting for, for this thing so I am going to do this little Update.  

 I do not have a scale so I cant say what the weight is with the alloy nut .  However holding the Troy in my left hand and the SMR MKII in the right, there is a negligible difference in the felt weight of the two.  I really do not know the weights off hand for either one, the G rail could be a lot heavier but It just does not feel it in my hand.  The alloy nut itself is very very light it so light my friend accused it of being plastic.

I mocked this rail up on the same upper receiver with the same old take off barrel and I am much happier with the SMR.   I like the attachment system way better.  The barrel nut is very long and machined to a perfect fit in to the rail system.  Any torque from loading up a bipod etc, is going to be spread out over a larger contact area and minimized, rather than directly applied  to the area where the barrel mates to the receiver.  This is just my personal opinion and not a claim by anyone other than me.  I have seen POI shifts with FFTs when shot with a lot of pressure applied to the forend, especially near the end where  a bipod is mounted.  I also really like the way the mounting system works over all,  it seems like a much more robust system than the Troy does.  Though this one was gifted to me, I see more in my future, to compliment my G triggers!.   Bill Thanks so much for the awesome gift!  It really did make for the best Christmas Ever!

I will update this thread again, or start a new one when this one has been archived since my barrel didnt ever arrive,  when I actually build this rifle up.  I am hoping to do some sort of actual test to see if my idea holds water. Ill use 3 different forends on the same rifle with the same bipod shoot 5 shot groups with each and see if there is any change at all in the 3.

Nope. Love mine.

What's wrong with yours?

I dont have anything wrong with my rail. I have the same one in FDE.

It does'nt want to mount straight.  With my best efforts it angles down enough to leave a gap between the receiver and the forearm on the top and it slightly crooked to the receiver left to right.  The fact the whole thing 15" in total length is only held on by three tabs the size of my pinker finger nail, does'nt inspire much confidence either.

Sell it and get an APEX

If you have some kind of scope mount use that to hold the rail and the upper together while you tighten the screws down.

I've been using my rifle for about a year now with the Alpha rails and have no issues at all.

I was considering an Alpha rail myself but the mounting does have me concerned,  seems like the small channel that the barrel nut teeth are trapped in is where all the pressure would be, instead of spread out over the whole barrel nut?  Can someone give a better explanation?

Mines solid.. I just don't like the lack of decent grip panels for it.

nope that channel and the 3 tiny little tabs are what take all the stress.

That's what I was thinking, doesn't seem very solid to me. At least the older design spread the pressure over the whole width of the barrel nut.

Did you contact Troy about the matter?

No i didnt contact troy, I did the research I should have done, before I bought it.  I found out this is a common problem and I need to try different barrel nuts until I find one that this rail likes.

I love my Alpha, and I'm very impressed by the way the rail locks into the barrel nut. Mine is rock solid. Did you do like the above poster recommended and use a scope mount, etc. to keep the rail straight while you assemble it? I used a LaRue scope mount when I installed my rail.

I tried to tell ya brah

You did, and I did not listen, I can tell you I learned my lesson and I will not side step quality for cheap again,  even if I have to wait through a panic.

I love mine mounts up straight & solid..

Nice Camo Job.  I am not trying to totally bash the Troy, I am sure it works fine for a lot of people and if I swap this nut out it will probably go on straight.  I just dont care for how it mounts even if it goes on correctly.   Particularly with the 15 inch rail, with a bipod at the end, I just have to wonder what kind of impact that is going to have on accuracy when I load the bipod up.  That 15" is going to be a long lever applying a lot of force directly to the barrel nut in ways I dont think would be as severe with other mounting systems on other rails.   If that makes any sense.

I used the scope base on my recce to hold the rail & upper together straight as I tightened everything down.. Rock solid, no poi shift between bag or bipod.. Honestly I prefer this method of mounting over the older extreme mounting setup.. Those pinch bolts sucked..

As for the camo job, nothing special. Just rustolem tan base with rustolem brown sprayed thru a toddlerized laundry bag netting..

Best rails made, IMO.

There are some close ones, but the bang for the buck is definitely with the TRX/Alpha.

I've beat the crap out of mine when I had it, and it never came loose or needed adjustment.

Edited...VA-gunnut


 

You want me to dispose of it for ya?

Funny.  3 of mine have seen some fairly heavy abuse and none of them have ever come loose or gone off center.

In your mockup, did you actually tighten all of them?

The problem is most likely your upper or the nut being canted, not the rail.  Thats the thing about floating rails like this though.....if your upper has a minor issue, this will be the kind of rail that will point it out.

Yes I tightened all of them,  If I was to bet on it I would say its the barrel nut this out of whack.  I just dont like the design.  I am glad it works for you guys,  I am just going to go a different route in the future.

I love mine. Locks up tight on my BCM. My only problem with it was the directions..........or rather lack of directions.

My 7 year old daughter could of written up a better manual.

I am liking the Squid grips a lot.

I have a few Alphas and Bravos (same mounting method) and haven't ever had any of them come loose, even with hard use. I have one of these that I use to assemble all of my uppers, though:



http://www.midwayusa.com/product/425110/yankee-hill-machine-upper-receiver-picatinny-rail-vise-jaws-ar-15

Personally I prefer the old trx rails over the alpha.
Wish Troy didn't discontinue the original and gave us a choice.
As already pointed out, it could be the upper or barrel nut that is canted.

That looks like a good tool to have.

I originally choked on the price, but after I finally bought one, I wondered how I ever built an upper without it. It's worth every penny.

I only have one Troy Alpha rail, and I did find that there is variation between barrel nuts.  When I first mounted the rail up, it wasn't quite straight, but it was usable.  I tried a different barrel nut, and it was much closer, almost perfect.  The Alpha mounting system is much better than the trx system though.

If you're looking for a perfectly straight rail, you're gonna have to spend more money or hope you get lucky.  Really, if it's extremely important to be perfectly straight, you'd be better off getting a monolithic upper.

How is it any better at aligning a rail and receiver different than a good quality carry handle?





 

It's not. You run the risk of cracking the upper. You need Ann upper block, with insert.

You don't use it to torque the barrel nut. You just use it to hold a top rail on a forend in perfect alignment with the top rail of the upper while you tighten the forend's mounting system (jam nut, clamping system, etc). You still use a clamshell or claw type block to tighten the barrel nut... It is a perfect tool for it's intended purpose, which is what the OP was talking about.



It works better than a carry handle because there is more contact surface on the rails (on the upper and the forend) for perfect alignment every time.

Bump for update

Well, That is Super Cool