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View Full Version : Picked up a CTR and it won't fit....



S391
7 October 2009, 20:48
I bought a used Magpul CTR off EBay and when I got it home I couldn't get it to fit on my AR. I was 99.9% sure that I had a commercial buffer tube but I must have been wrong..... this thing isn't anywhere near being able to fit on the gun.....

Crap. Anyone need an OD Magpul CTR?

federalist22
8 October 2009, 02:04
Too big, too small?

Sounds like too small. Look at the back of the tube, does it have an angle, or is it flat? If it has an angle it is definitely commercial; if it is flat, it could be commercial, but is most likely mil-spec, which would also be smaller in diameter, so the CTR should either fit or be loose if the stock is commercial diameter. Sounds like you have a mil-spec CTR and a commercial tube. Get your measuring tape out and you will have to convert things like 1/8 to decimals to distinguish between 1.14 (mil-spec) and 1.17 (commercial) -http://www.magpul.com/pdfs/technotes/ctr/buffertubeid.pdf. Scooby Doo is that your EBay vendor either sold you a stock for the wrong dimension, or they sold you a Chinese Magpul (fake--there are probably some out there). Did you get the Magpul mfr box with it? There should have been a florescent yellow/green paper insert with the comparisons between mil=spec and commercial diameters like the link I posted here.

The fix for this is to go to one of the Dealers listed on the right of this forum and procure a VLTOR mil-spec tube, or you can sell/trade it like you are trying to do here. I forgot to read that last line before I typed the above, so I figured I would leave it. Sorry.

rob_s
8 October 2009, 05:29
If you bought a commercial stock and have a milspec tube the stock will have excessive wobble, not be impossible to install. Something is amiss.

S391
8 October 2009, 07:36
Too big, too small?

Sounds like too small. Look at the back of the tube, does it have an angle, or is it flat? If it has an angle it is definitely commercial; if it is flat, it could be commercial, but is most likely mil-spec, which would also be smaller in diameter, so the CTR should either fit or be loose if the stock is commercial diameter. Sounds like you have a mil-spec CTR and a commercial tube. Get your measuring tape out and you will have to convert things like 1/8 to decimals to distinguish between 1.14 (mil-spec) and 1.17 (commercial) -http://www.magpul.com/pdfs/technotes/ctr/buffertubeid.pdf. Scooby Doo is that your EBay vendor either sold you a stock for the wrong dimension, or they sold you a Chinese Magpul (fake--there are probably some out there). Did you get the Magpul mfr box with it? There should have been a florescent yellow/green paper insert with the comparisons between mil=spec and commercial diameters like the link I posted here.

The fix for this is to go to one of the Dealers listed on the right of this forum and procure a VLTOR mil-spec tube, or you can sell/trade it like you are trying to do here. I forgot to read that last line before I typed the above, so I figured I would leave it. Sorry.

Thanks, the back of the tube is angled so it appears to be commercial.... for some reason I thought that the mil-spec tubes were larger..... Doh....

I'll dig through this some more and figure it out. I'll have to pull out my calipers and see what I'm dealing with. I've been working on my AR for a few weeks and so far this is the only hitch..... Not too big of a deal but it's a drag when you figure out you did something wrong.

For the record, I bought the stock off Ebay and it was used but I though that the former owner listed it as a commercial CTR... I'll have to double check.

Thanks for the info.

S391
8 October 2009, 07:37
If you bought a commercial stock and have a milspec tube the stock will have excessive wobble, not be impossible to install. Something is amiss.

It would seem that I have a commercial tube and a mil-spec stock.... but I need to do some more research to nail it down.....

caporider
8 October 2009, 07:40
The commercial CTRs always have the thicker buttpad. Milspec CTRs never ship this way from Magpul (although it is possible for an end user to put the thicker pad on the milspec stock).

S391
8 October 2009, 07:44
The commercial CTRs always have the thicker buttpad. Milspec CTRs never ship this way from Magpul (although it is possible for an end user to put the thicker pad on the milspec stock).

Thanks everyone, I have to pull out the calipers and see what I'm dealing with but it appears that I have a commercial tube and a mil-spec stock....

The listing for the stock clearly states that it's a commercial unit but I have an idea that the kid knew it was not a commercial unit since my emails to him went unanswered after I bought the stock.....

My bad.... but I'll sell it at my club and order the correct size from my dealer... it's all good.

federalist22
8 October 2009, 13:45
The commercial CTRs always have the thicker buttpad. Milspec CTRs never ship this way from Magpul (although it is possible for an end user to put the thicker pad on the milspec stock).

The thicker buttpad accommodates the the extra length (6th-pos) of the commercial tuber in a recessed area where the tube meets the stock/pad.

I know this because I have gone through this.

federalist22
8 October 2009, 14:49
Check one of the sites on the right of this page, like Rainier, BC, Black Bear, or got to Arizona Armament I know they have some stuff.

rob_s
8 October 2009, 15:26
S391, if your stock was black I'd swap you for my commercial black one.

HS2
8 October 2009, 17:45
Thanks everyone, I have to pull out the calipers and see what I'm dealing with but it appears that I have a commercial tube and a mil-spec stock....

The listing for the stock clearly states that it's a commercial unit but I have an idea that the kid knew it was not a commercial unit since my emails to him went unanswered after I bought the stock.....

My bad.... but I'll sell it at my club and order the correct size from my dealer... it's all good.

Its pretty easy to replace the tube and the tube is cheaper than a new stock.

S391
8 October 2009, 17:53
S391, if your stock was black I'd swap you for my commercial black one.

With enough Krylon anything can be black :)

Beaux
9 October 2009, 04:31
You can usually tell milspec vs. commercial by thread height. If the threads appear to be even with the OD of the tube it's commercial. If the threads look higher than the OD of the tube it's milspec.

S391
13 October 2009, 19:15
Its pretty easy to replace the tube and the tube is cheaper than a new stock.

Yup, it seems like I may be going that direction.....

S391
14 October 2009, 13:22
I have a mil-spec buffer tube on the way.... the problem should be solved.

Thanks guys.

S391
15 October 2009, 18:53
Ok, I got my new mil spec buffer tube this afternoon and got it all swapped around. We're good to go. I'll post pics later.

Thank you to everyone for the help.

Stickman
15 October 2009, 19:11
Ok, I got my new mil spec buffer tube this afternoon and got it all swapped around. We're good to go. I'll post pics later.

Thank you to everyone for the help.




Sounds like you are back in business!

S391
19 October 2009, 08:16
The Magpul CTR is a great stock and I'm glad that I decided to go this route... thanks for the help everyone.

http://i21.photobucket.com/albums/b283/S682/AR/IMG_1209.jpg

http://i21.photobucket.com/albums/b283/S682/AR/IMG_1212.jpg

Rommel
20 October 2009, 17:32
I believe Mil-spec CTRs are now shipping with the rubber butt-pad . . . at least the one I bought did.