UBR Installation- Help Please

[edwordsigh]

Hello yall.

I've been trying to install my UBR into my noveske lowever for the past 30 mins. I'm having trouble fitting the UBR main tube into the Lower reciever. It seems that the UBR won't seat right into the lower reciever. Has anyone else have the problem? Am I forgetting something?

SF,
Ed

[ralphlyerly]

Stickman has a good description of the installation of the UBR stock at the following link http://www.weaponevolution.com/forum/showthread.php?p=314

[edwordsigh]

Thanks for the post Ralphlyerly. Ive been to that site and some others as well. They all have some great info on how to install, but didnt cure my problem with the fitting of the ubr with my lower. I came to a conclusion that my lower or my ubr was a hair out of spec, causing a not so perfect fitting. I brought it over to my local shop and they came to the same conclusion, we had to do some "customizing" to make it fit nice and tight.

[mpardun]

This could be yet another case of not knowing if your AR is Mil-Spec or Commercial buffer tube.

The spec is significant enough that if you have the wrong one, you will run into problems. Careful with your lower until you know.

[Robb Jensen]

This could be yet another case of not knowing if your AR is Mil-Spec or Commercial buffer tube.

The spec is significant enough that if you have the wrong one, you will run into problems. Careful with your lower until you know.

The UBR uses a 'entry' length rifle receiver extension. Their ain't no such animal as a mil-spec or commercial diameter rifle style extension (rifle length or entry length), they're all the same.

[mpardun]

The UBR uses a 'entry' length rifle receiver extension. Their ain't no such animal as a mil-spec or commercial diameter rifle style extension (rifle length or entry length), they're all the same.

Point Taken GotM4...I didn't mean to imply length is the issue.

I wasn't sure if Magpul was making 2 buffer tube extension diameters for the UBR proprietary buffer tubes they bundle with the UBR - as they do for the CTR. There have been many people trying to get a commercial CTR to fit a Noveske (or other milspec) diameter lower & visa versa. Whereas I understood the commercial versions were designed to fit slightly out of spec lowers produced by some (incl: Sabre, BM, RRA DPMS, Oly @ 1.17 versus the MilSpec diameter @ 1.14 that Colt, Noveske and others use).

I am happy to admit I am wrong.

[edwordsigh]

The UBR uses a 'entry' length rifle receiver extension. Their ain't no such animal as a mil-spec or commercial diameter rifle style extension (rifle length or entry length), they're all the same.

That is absolutely correct. With the UBR, there is no mil nor commercial spec. I simply had a hardtime flushing the UBR with the lower receiver. Ive heard that its a really tight fit on many lower receivers, unfortunately for me, it was too tight and had to use other ways to get the sucker in. However, it's a great stock and gawd it's solid.

I do have a Noveske Lower, anyone here have problems installing their UBRs with the Noveske?

[Robb Jensen]

Point Taken GotM4...I didn't mean to imply length is the issue.

I wasn't sure if Magpul was making 2 buffer tube extension diameters for the UBR proprietary buffer tubes they bundle with the UBR - as they do for the CTR. There have been many people trying to get a commercial CTR to fit a Noveske (or other milspec) diameter lower & visa versa. Whereas I understood the commercial versions were designed to fit slightly out of spec lowers produced by some (incl: Sabre, BM, RRA DPMS, Oly @ 1.17 versus the MilSpec diameter @ 1.14 that Colt, Noveske and others use).

I am happy to admit I am wrong.

I wasn't saying that you were saying it was a length issue either.
I think you are missing the point that entry length receiver extensions are unlike both commericial and mil-spec CAR receiver extensions. They are totally different. A entry length receiver extension is very much the same as a rifle length extension but it's just shorter (mounts to the lower the same as a rifle length extension), because it's shorter it uses the CAR length buffers and springs.

The UBR, RRA Entry and Sully stock all use entry length rifle style extensions, these don't have the milled area on the bottom where a collapsible stock has the stops milled in it. Rifle and entry length receiver extensions are round, they also don't use castle nuts or receiver end plates. It would make ZERO sense to make two different diameters of rifle style extensions for these stocks.

For example here's from the parts list from RRA:

AR0113A - Receiver extension, CAR $18.00 (fits all commercial CAR/M4 stocks)
AR0113B - Receiver extension, standard $17.00 (fits A1/A2 & PRS stocks)
AR0113T - Receiver extension, entry length $20.00 (fits Sully, UBR and RRA entry stocks)

The only stock that Magpul made that truly used a proprietary extension was the 93 series of stocks.

The difference between commercial CAR extensions and mil-spec extensions is because it's simply cheaper to make CAR extensions. This why commercial tubes are typically under $20 and mil-spec extensions are in the $40s.
Commercial extensions weren't made for differences in the lowers. I've yet to see any lower that wouldn't accept a mil-spec extension (unless someone F'd up the threading on the lower which I have seen).

[molsen]

How old is the Noveske lower? There are some out there that are known to be out of spec.

[mpardun]

I wasn't saying that you were saying it was a length issue either.
I think you are missing the point that entry length receiver extensions are unlike both commericial and mil-spec CAR receiver extensions. They are totally different. A entry length receiver extension is very much the same as a rifle length extension but it's just shorter (mounts to the lower the same as a rifle length extension), because it's shorter it uses the CAR length buffers and springs.

The UBR, RRA Entry and Sully stock all use entry length rifle style extensions, these don't have the milled area on the bottom where a collapsible stock has the stops milled in it. Rifle and entry length receiver extensions are round, they also don't use castle nuts or receiver end plates. It would make ZERO sense to make two different diameters of rifle style extensions for these stocks.

For example here's from the parts list from RRA:

AR0113A - Receiver extension, CAR $18.00 (fits all commercial CAR/M4 stocks)
AR0113B - Receiver extension, standard $17.00 (fits A1/A2 & PRS stocks)
AR0113T - Receiver extension, entry length $20.00 (fits Sully, UBR and RRA entry stocks)

The only stock that Magpul made that truly used a proprietary extension was the 93 series of stocks.

The difference between commercial CAR extensions and mil-spec extensions is because it's simply cheaper to make CAR extensions. This why commercial tubes are typically under $20 and mil-spec extensions are in the $40s.
Commercial extensions weren't made for differences in the lowers. I've yet to see any lower that wouldn't accept a mil-spec extension (unless someone F'd up the threading on the lower which I have seen).

Roger that...appreciate the info.

[Federale]

How old is the Noveske lower? There are some out there that are known to be out of spec.


I had a Noveske Lower that I had to return because magazines wouldn't drop free. That was about 18 months ago, so yes, I can attest that there was a run of out of spec Noveske lowers.

[Stickman]

Stickman has a good description of the installation of the UBR stock at the following link http://www.weaponevolution.com/forum/showthread.php?p=314


While the basic info is similar, that needs to be rewritten to show the production model installation. The prototype used an allen wrench, while the production models use a slotted/ flathead, and include a drain hole.

[edwordsigh]

Yes, I agree with both of you guys. I do believe that my Noveske is a bit out of spec if this were to happen. However, surprisingly, the Noveske was purchased not too long ago (2 months ago?)


I had a Noveske Lower that I had to return because magazines wouldn't drop free. That was about 18 months ago, so
yes, I can attest that there was a run of out of spec Noveske lowers.


How old is the Noveske lower? There are some out there that are known to be out of spec.

[Razorhunter]

Ok, so you guys are saying the UBR will need an "Entry Length Rifle Receiver Extension"???
I have never heard of such a buffer tube before, but from what I gather, it sounds like it's just a buffer tube, that is of the same design as an A2 RIFLE BUFFER, but it is SHORTER than a standard A2 rifle buffer. ???
Is this correct?

IF SO, then WHO makes a nice one??? IF my description above is correct, then it SOUNDS to me (and I could be wrong), like neither Colt, or LMT make such an extension.
If this is ALSO correct, then WHO manufactures a nice "Entry length rifle receiver extension" that could be used with the UBR stock????
I need to get this right, and get one ordered, and would love to finally get this cleared up. Thanks guys.


Heck, let me ask this also. Can someone tell me of an AR15 that actually has this "Entry length rifle receiver extension" on it from the factory? Which AR(s) actually already have this exact extension on them from the factory, as new weapons????
EVERY AR I know of, has either a 4 position (Colt), or 5-6 position standard collapsible stock buffer tube, OR they have a fixed A2 stock with rifle buffer tube on them. Is there an AR that already has this "entry length rifle receiver extension" already on it???
Thanks.

[Federale]

The UBR comes with its own buffer tube. I'm 100% positive that this is NOT a case of the OP having a milspec or a commercial tube.

To paraphrase mpardun, "This could be yet another case of not knowing what buffer tube comes with the UBR." :)

[edwordsigh]

Yes, the UBR comes with everything you need except for the buffer and buffer spring.

Am I the only poor bastard with a problem fitting their UBR with their lower?:( I almost feel like I did something wrong on my part, lol.


The UBR comes with its own buffer tube. I'm 100% positive that this is NOT a case of the OP having a milspec or a commercial tube.

To paraphrase mpardun, "This could be yet another case of not knowing what buffer tube comes with the UBR." :)

[Robb Jensen]

Ok, so you guys are saying the UBR will need an "Entry Length Rifle Receiver Extension"???
I have never heard of such a buffer tube before, but from what I gather, it sounds like it's just a buffer tube, that is of the same design as an A2 RIFLE BUFFER, but it is SHORTER than a standard A2 rifle buffer. ???
Is this correct?

IF SO, then WHO makes a nice one??? IF my description above is correct, then it SOUNDS to me (and I could be wrong), like neither Colt, or LMT make such an extension.
If this is ALSO correct, then WHO manufactures a nice "Entry length rifle receiver extension" that could be used with the UBR stock????
I need to get this right, and get one ordered, and would love to finally get this cleared up. Thanks guys.


Heck, let me ask this also. Can someone tell me of an AR15 that actually has this "Entry length rifle receiver extension" on it from the factory? Which AR(s) actually already have this exact extension on them from the factory, as new weapons????
EVERY AR I know of, has either a 4 position (Colt), or 5-6 position standard collapsible stock buffer tube, OR they have a fixed A2 stock with rifle buffer tube on them. Is there an AR that already has this "entry length rifle receiver extension" already on it???
Thanks.

Yes Paul the UBR uses (and comes with one) a entry length rifle receiver extension. These extensions are also used in the RRA Entry stock as well as the excellent Sully stock. It's short like a CAR receiver extension and share the CAR length buffer and spring.

[Razorhunter]

Ok, gotcha, and thanks,

So, which buffer need be used with a UBR and my Colt 6920?

How about with a UBR and a midlength AR?


I have always run either "H" or "H2" buffers in my 6920's, and usually run "H" buffers in my midlength guns.
What buffers will I need to use if I put a UBR on either of these guns?



Is the "CAR" buffer (also known as a "standard" buffer) used in the UBR in conjunction with EITHER of these guns I have listed ???? (basically asking about a midlength AND a carbine length gas system here)..
Thanks guys.

[Robb Jensen]

Ok, gotcha, and thanks,

So, which buffer need be used with a UBR and my Colt 6920?

How about with a UBR and a midlength AR?


I have always run either "H" or "H2" buffers in my 6920's, and usually run "H" buffers in my midlength guns.
What buffers will I need to use if I put a UBR on either of these guns?



Is the "CAR" buffer (also known as a "standard" buffer) used in the UBR in conjunction with EITHER of these guns I have listed ???? (basically asking about a midlength AND a carbine length gas system here)..
Thanks guys.

With a midlength I recommend a CAR buffer and standard rate CAR spring.

With a 6920 I recommend a H buffer. A H2 in a 6920 won't hurt either, some guns 'feel' better with them as well.

CAR (3.0oz)
H (3.8oz)
H2 (4.6-4.7oz)
H3 (5.5-5.6oz)