Magpul CTR, any way to actually make it work as advertised?

Stevo

Stevo

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So I just bought a Magpul CTR stock. I'd handled one previously and was impressed with how snug it fit on the stock when the friction lock was applied.

This CTR of mine doesn't fit any better than the cheap stock that came with my Armalite. Even with the friction lock applied it's got as much movement fore-and-aft as the regular stock.

Yes, it's a commercial-spec stock. Yes, I've tried it on two different commercial-spec buffer tubes. Same stock slop on both tubes.

I'm quite underwhelmed by this stock. Is there any way to make it work like I expected it to, or is the hype better than the product?
 
i havent had issues with the 2 CTRs ive owned, and have thoroughly enjoyed their strength and ruggedness.

As for suggestions, I imagine you've tried nearly everything. Maybe the stock itself is the issue, can you try someone else's on the those tubes?

Keep us posted.
 
I dunno, I have two different CTRs and a few different brands of Milspec tubes, LMT, VLTOR and a generic brand. They all fit rock solid no movement at all.
 
If I hold the friction lock all the way closed with my hand, it seems to work correctly.

If I let go of it it springs open far enough to stop doing it's job.
 
Doesn't surprise me.
All the mil-spec Magpuls I have used tighten up nicely.
The commercial tubes are all over the place and the commercial stocks have to be made for the largest tolerance so unless you have the fatty tube it is going to be sloppy.
I never use commercial extension tubes anymore.
 
Urban_Ops said:
Doesn't surprise me.
All the mil-spec Magpuls I have used tighten up nicely.
The commercial tubes are all over the place and the commercial stocks have to be made for the largest tolerance
Click to expand...

I don't think it's the tube(s) that's at fault. Read my last post.

Does this thing require a break-in and Loc-tite like an XCR?
 
I have a DPMS commercial buffer tube and a commercial Magpul CTR and with the friction fit engaged its rock solid (you can still physically move the stock back and forth, but it wont move on its own. There is zero rattle).

What brand of tube did you get? and are you 100% SURE its commercial spec, or is it possible its a Mil. Spec. stock? (maybe an accident in shipping a mil. spec. rather than commercial?)


Do you have a micrometer handy at all? Commercial buffer tubes are supposed to have a diameter of 1.17 inches, IIRC Mil Spec ones are 1.14". If possible can you measure and double check if your stock is a Mil. Spec or Commercial.?


The reason I ask, is that if you had a Mil. Spec. tube & commercial stock, it wouldn't be tight at all, even with the friction lock... The Mil. Spec. CTR wouldn't even fit on the commercial stock, it would be ULTRA tight.
 
Yes, I am 100% sure both of my buffer tubes are commercial-spec. They both have the slanted end and both mic out from 1.168 to 1.172" at various spots along their length.

Yes, it's a commercial CTR. The box is marked that way and it has the rubber butt pad that the mil-spec one does not come with.
 
If you take the stock off and look inside you'll see two tiny tangs of plastic that squeeze the tube. Are these tangs ok? they should look "L" shaped (look for flattened or mushroomed ends).

If that's all good, I don't know how you can modify the stock to squeeze tighter. I have one Ill take a look and post if I see an easy solution.
 
Stevo said:
Yes, I am 100% sure both of my buffer tubes are commercial-spec. They both have the slanted end and both mic out from 1.168 to 1.172" at various spots along their length.

Yes, it's a commercial CTR. The box is marked that way and it has the rubber butt pad that the mil-spec one does not come with.
Click to expand...

You've been had by shady merchants!? ;)

Gadzooks!
 
G37 said:
If you take the stock off and look inside you'll see two tiny tangs of plastic that squeeze the tube. Are these tangs ok? they should look "L" shaped (look for flattened or mushroomed ends).

If that's all good, I don't know how you can modify the stock to squeeze tighter. I have one Ill take a look and post if I see an easy solution.
Click to expand...

They look fine.

When I squeeze the friction lock fully closed, it works as advertised.

If I take my hand off it relaxes slightly and this is enough to remove the majority of the clamping pressure.
 
I think I solved it... pics and description coming soon (mine had similar issue; although minor, this was on my list of "to do's").
 
G37 said:
I think I solved it... pics and description coming soon (mine had similar issue; although minor, this was on my list of "to do's").
Click to expand...

I think I've got it, too. The lever isn't pushing the tabs in far enough to create enough friction. If I put a shim between the lever and the tabs (I used a slice of a business card) it works correctly.

It looks like I need to remove the roll pin at the front of the lever and figure out a way to permanently attach a shim to the inside of the lever or the sides of the tabs.

Edit: Magpul includes in the box a dimensional chart with the various dimensions and specs of the commercial and mil-spec tubes. Every area of my two tubes measures within the dimensions Magpul lists on the sheet. I'm surprised that it doesn't work correctly when it's within the specs listed.
 
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