mp 15, brand new with loose rail

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I have a new mp 15, and I put a fore grip on it and noticed the troy quad rail that came with it stock was a little loose, It's not bad, but I want a tight fit. It's a drop-in rail. I pulled it out yesterday and put it back in, but still just a little loose. Any suggestions? I was surprised that the quad rail had no screws, or any place you could put screws? Anyway, I am a newbie and would appreciate any help. Thanks!
 
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The drop-ins will always be loose. If you do not have a certain amount of tolerance, you could not put it together. If you want tight without a hint of movement, you need a free float with the special barrel nut.

The fore grips, particularly the vertical handles, give you more leverage on the forend so the slack is more noticeable.
 
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Mine is loose too--very loose. It dramatically affects POI and makes this weapon very inaccurate. It was bad enough that the barrel was misaligned so bad that it wouldn't even zero at 25 yards. S&W did fix the barrel but neglected the very loose quad rail. Spending a grand or more on a weapon that is not serviceable is revolting. I'll not likely ever purchase another S&W product as their quality control is out of control and their customer service is left wanting.
 
Yet another reason why you should pay a little more for ff or swap out asap when making a rifle purchase!
 
Yet another reason why you should pay a little more for ff or swap out asap when making a rifle purchase!

And what is that reason? Tromper's problem was in no way related to a drop in rail, which is really nothing more than a replacement hand guard. There was something else wrong with that rifle, such as a loose barrel nut. It wasn't because of a little play in the hand guard.
 
That's right cyphertext. Suggesting that I spend another $250 or so on a rifle that's supposed to be accurate to 1 moa after already spending abt $1000 seems out of line. It seems to me that if I build my own and if there's a problem, at least I won't have to keep sending it back to the factory --- it will already be there.
 
That's right cyphertext. Suggesting that I spend another $250 or so on a rifle that's supposed to be accurate to 1 moa after already spending abt $1000 seems out of line. It seems to me that if I build my own and if there's a problem, at least I won't have to keep sending it back to the factory --- it will already be there.

Did S&W detail what was wrong with your rifle when they sent it back to you?
 
I have a new mp 15, and I put a fore grip on it and noticed the troy quad rail that came with it stock was a little loose, It's not bad, but I want a tight fit. It's a drop-in rail. I pulled it out yesterday and put it back in, but still just a little loose. Any suggestions? I was surprised that the quad rail had no screws, or any place you could put screws? Anyway, I am a newbie and would appreciate any help. Thanks!

Should have got the new M&P 15T with the industry standard UTG.. much better than that crummy Troy. (just kidding)
 
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Should have got the new M&P 15T with the industry standard UTG.. much better than that crummy Troy. (just kidding)

Hilarious Phil. Actually, should have bought Colt, LMT, Noveske, Daniel Defense or any other quality rifle.
 
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Maybe I'm missing something. How does a handguard affect the accuracy of a rifle?

As the rifle turns from side to side the sight picture can change quite a lot - as in the shooter is not perfectly still and holding the rifle still from shot to shot. The experience is that the front sight moves from left to right. In actuality, both front and rear sights move but given the same cheek position, it will appear to the shooter that the front sight moves back and forth within the aperture. Try looking through any sights and canting the rifle back and forth and you will see what I mean. Mine is so loose that if I turn the rifle with the pistol grip it appears that the front sight moves completely out of the rear sight aperture. I suppose accuracy is not the exact term since the rifle may be accurate - consistency of shot placement may be a more appropriate term. The only way I can get consistent shots is to always have it twisted to the right and that just sucks.
 
As the rifle turns from side to side the sight picture can change quite a lot - as in the shooter is not perfectly still and holding the rifle still from shot to shot. The experience is that the front sight moves from left to right. In actuality, both front and rear sights move but given the same cheek position, it will appear to the shooter that the front sight moves back and forth within the aperture. Try looking through any sights and canting the rifle back and forth and you will see what I mean. Mine is so loose that if I turn the rifle with the pistol grip it appears that the front sight moves completely out of the rear sight aperture. I suppose accuracy is not the exact term since the rifle may be accurate - consistency of shot placement may be a more appropriate term. The only way I can get consistent shots is to always have it twisted to the right and that just sucks.

The first AR I bought years ago had a standard hand guard that I replaced with a quad rail. That rail sat sloppily in the forward and rear channels that held them in place, alot like you describe. I took some black electrical tape and cut it into thin strips that simply covered the forward lips on the unistalled rails, then re-installed them. It tightened them up while affording me a "cushion" to be able to snap them into place. Never had another problem with them. Took me 10 minutes and cost .000000003 cents.
 
Thanks Moe, sounds like a good idea. I just found that suggestion on another site. May also be that the delta ring spring is also just too weak. Electrical tape seems to be the gun owner's duct tape. A tip for you in return -- whenever someone recommends electrical tape I usually substitute hockey tape. Great for no slip applications. I have even used it in scope rings. It's a pain to get the scope leveled but once you do no scratches and it won't ever slip on you.
 
Thanks Moe, sounds like a good idea. I just found that suggestion on another site. May also be that the delta ring spring is also just too weak. Electrical tape seems to be the gun owner's duct tape. A tip for you in return -- whenever someone recommends electrical tape I usually substitute hockey tape. Great for no slip applications. I have even used it in scope rings. It's a pain to get the scope leveled but once you do no scratches and it won't ever slip on you.

Your welcome. Hope it works. Thanks for the hockey tape idea. I've used electrical tape in case I happen to be caught out in a thunderstorm. Can't be too careful. ;)
 
Wait, Tromper, is your front sight mounted to a drop in forearm?

Good question, but even I am not that simple. To be clear this is a M&P 15X with A2 front sight often referred to as an a-frame front sight.
 
The drop-ins will always be loose. If you do not have a certain amount of tolerance, you could not put it together. If you want tight without a hint of movement, you need a free float with the special barrel nut.

Not true. My drop in 2 piece Knights Armament is solid as a rock. It has a securing screw and backing plate that locks everything real tight.
 
Not true. My drop in 2 piece Knights Armament is solid as a rock. It has a securing screw and backing plate that locks everything real tight.

I don't think you can compare that one to the typical 2 piece drop in rail... for $351 MSRP, it better lock up tight! ;)
 
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