M&P 15 PSX

[erigel825]

This is my second post so bear with me. Today I picked up my M&P 15 PSX first Smith and Wesson and also first AR style firearm. I noticed the Troy drop in MRF twists a few millimeters side to side. I too it off the barrel and put it back on and it did not change anything. I noticed some other people on the internet had the same problem with the PSX, but could not find any solutions or what their outcomes were. Should I call S&W or is this normal with this gun and MRF? Thanks for your time and help.

Eric

 

[PSP-Ret]

erigel25,
I would like to be able to help you since I just got my first AR 3 weeks ago and I got the same S&W M&P 15 PSX and I love it. Constantly learning about it but I hate to admit it but I don't know what MRF is????? I probably do, but just can't put the letters together to understand what it stands for.
Let me know and I might be able to help cause I've been all over this puppy learning what does what and hdow to take it apart etc.

 

[erigel825]

PSP
Thank you the MRF is the modular rail forend or the Troy Quad Rail where a foregrip, flashlight, laser etc. attach to. It twists a few millimeters to each side, does yours do this? Thanks again for your help

Eric

 

[MPDC]

If it doesn't move where it is mounted to the receiver (no play or loseness allowing movement at the attachment point) it is fine. It is a "free floating" rail which simply means motions induced in the rail won't effect the receiver/bbl. combination since they are not transmitted by the rail to the bbl. where movement (more likely the further from the receiver you move) could effect accuracy of a shot.

A non "free float" rail has an attachment point at the front as well so the bbl. IS effected by movements at the front end of the rail, even if the receiver end is held rock solid. Make sense?

 

[Foxtrot]

What MPDC said

Maybe I am not reading the post correctly. You said drop in.

Do you have the Troy MRF version or the Troy MRF-DI version? (the DI at the end is a contraction from the product code number to designate Drop In and is used by some retailers of troy products, for example > http://www.opticsplanet.net/troy-modular-rail-forend-drop-in.html where the product code number is OY-SY-MRF-DI-SRAI-MRF-D7BT-00. I use it here to seperate the differences between free float MRF and the non-free float MRF classes of the troy series)

Non free float drop in > http://troyind.com/%20/battlerails/troy-battlerail-drop-in-carm4

Free float > http://troyind.com/%20/battlerails/troy-battlerail-mrf-c-7

They are both Troy MRF series.

The Troy MRF version is free float, the Troy MRF-DI version is not free float. If its a drop in sized and installed correctly it should not "twist" around side to side like the picture i'm getting from the post's, maybe i'm not reading them correctly. You said drop in so i'm assuming you have the drop in so its not free float I don't think. But this is the PSX model too so I don't know if the physical mechanisims at the front rear are there which keep the handguard from "twisting" around. In the normal handguards cap and delta ring arangement there is a physical arangement/shape that sort of index's the handguard in place but there can be a little movement though depending on fit. I don't know if the PSX does this or not. We use the primary arms quad rail handguard which is a perfect fit for our M&P OR's and its rock solid with no movement at all.

Generally, if it is free float then its possible for it to move some under lateral pressure if there is any "play" in the mounting but it generally takes a lot of pressure to make them move laterally like that.

Is it "twisting" as in a spiral direction/pattern or is the whole handguard turning?

 

[PSP-Ret]

erigel825,
I don't understand what PSX you got but my PSX does not come with a free floating hand gurad. I have the four picatinny rails all the way around my forearm and it is NOT free floating. Did you order it special with a free floater or did you put it on yourself.

 

[BeginingOfTheEnd]

This is my second post so bear with me. Today I picked up my M&P 15 PSX first Smith and Wesson and also first AR style firearm. I noticed the Troy drop in MRF twists a few millimeters side to side. I too it off the barrel and put it back on and it did not change anything. I noticed some other people on the internet had the same problem with the PSX, but could not find any solutions or what their outcomes were. Should I call S&W or is this normal with this gun and MRF? Thanks for your time and help.

Eric

It's not the upper rocking over the lower is it? Because There is a little movement between the two on most ARs'. If so there is a cheap part for that.

 

[erigel825]

Sorry I wasn't clear, it is definitely the standard drop in quad rail that comes with the PSX. I have taken it apart multiple times and its like it doesnt grip the sprocket like nut on the d ring. I have looked on troy industries website and I am installing it correctly. The entire grip when seated on the barrel will twist clockwise and counter clockwise around the barrel about 1-2 millimeters. Ill try to post a video of it later for you guys. Thanks for all help and suggestions so far.

Eric

 

[steven23]

I just received my PSX yesterday and it too has a slight shift back and forth in the handgaurd. I do not know if it is normal or not though. I would like to know also.

 

[PSP-Ret]

erigel and steven,
My PSX does not move so that means yours are broke so you'll have to send them to me and I will dispose of them in the proper fashon. I wouldn't want you to be using a weapon that is not safe...............not going for it are ya? I had to try.
Anyway if it doesn't affect your piston going down thru the forearm then I'd say keep shooting it.

 

[steven23]

Yeah, i was talking to one of my friends who is big in ar-15 type rifles, and he said every ar-15 will have that shift. Unless it is a free float, and non free float will have the shifting though. He even took a look at mine and said it is actually way better then any stock non free float that he has seen.