Larue OBR and AAC Muzzle Brake not properly seated

[SeaWolff]

I recently got in a Larue OBR 7.62 18" rifle. We were planning on running the AAC 90T muzzle brake because we got in an AAC MK-13SD to play with as a demo. Unfortunately the female threads on the brake itself are shorter than the threads on the OBR. Has anyone else had this issue? I talked to AAC and Larue and as usual its always the other guys fault. I may be ordering a Surefire can because I don't like the idea of having to have a spacer machined. The gap is roughly 1/8" which makes sense if Larue makes the threads .750" and AAC does the female threads .620"......

 

[poison123]

Re: Larue OBR and AAC Muzzle Brake not properly seated

Yup. Same exact problem when I had a OBR and AAC 18t mount.

 

[zenghost]

Re: Larue OBR and AAC Muzzle Brake not properly seated

Congrats on the OBR.

I had made a post not long ago about the thread length on the OBR as it relates to mounting suppressors. Had seen others on other forums having issues with this using AAC adapters specifically. In my case, I was concerned with a thread-mount suppressor - TBAC 30P-1 for an OBR I had on order.

Larue seemed to think it was not an issue. Further reading leads me to believe these "deeper" thread lengths are common on AR-10/OBR/MWS platforms. Not sure if this is true.

Thunderbeast Arms was exceptionally (and I mean EXCEPTIONALLY) responsive to my inquiry. TBAC is looking for .600 thread length and Larue is .750 from what I understand. I would need a spacer or as Zak explained I could foul/dirty the exposed threads and make removing the suppressor difficult (no thanks). Someone on another site suggested Larue will send out spacer kits, but I have no verification of that.

 

[WTC343]

Re: Larue OBR and AAC Muzzle Brake not properly seated

RMBradshaw,

Call LaRue and ask for Alfred, the shop manager. Tell him you need one of the spacers, and he will send you one no charge. I had the same issue with my AAC mount, but all I got from AAC was the runaround. LT is aware of it, and will hook you up. Install the spacer, use the appropriate shim and you are good.

 

[Outsydlooknin75]

Re: Larue OBR and AAC Muzzle Brake not properly seated

Imagine that ...

 

[zenghost]

Re: Larue OBR and AAC Muzzle Brake not properly seated

Talked to Larue today. Alfred is no longer working there, and the gentleman I spoke to was not aware of any such part. He did say if someone had an issue they could call in and talk to someone in the "gunroom" for a possible solution.

 

[Rhinomax]

Re: Larue OBR and AAC Muzzle Brake not properly seated

They do have a washer you can get. I got one a while back from Alfred.

 

[zenghost]

Re: Larue OBR and AAC Muzzle Brake not properly seated

I do believe you! I think the salesman had no idea though. May have to talk to one of the "shop" guys.

 

[K_4c]

Re: Larue OBR and AAC Muzzle Brake not properly seated

Keep us updated and if possible please provide a P/N!

 

[p951951951t]

Re: Larue OBR and AAC Muzzle Brake not properly seated

+1. I have a scar-H SD I'm planning on mounting to my OBR and I wonder if I'll run into the same problem.

 

[SeaWolff]

Re: Larue OBR and AAC Muzzle Brake not properly seated

I called Larue this morning and was told Alfred is no longer there; however, they told me they would send out a "spacer" but it was not something that they kept in stock. I tried to get a second one for my buddy who just got his OBR and they claimed to only have one. Once we get it in, we're going to take measurements and see what we need to make another one (assuming its not a standard peel washer or something of the sort)...Stay tuned. Thanks for the help on that WTC343

 

[WTC343]

Re: Larue OBR and AAC Muzzle Brake not properly seated

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: RMBradshaw</div><div class="ubbcode-body">I called Larue this morning and was told Alfred is no longer there; however, they told me they would send out a "spacer" but it was not something that they kept in stock. I tried to get a second one for my buddy who just got his OBR and they claimed to only have one. Once we get it in, we're going to take measurements and see what we need to make another one (assuming its not a standard peel washer or something of the sort)...Stay tuned. Thanks for the help on that WTC343 </div></div>

RMBradshaw, Glad to help!

It is a pretty simple part. Seems like somebody with a lathe or CNC and some know-how could turn out a bunch of them pretty quick. The one I got is parked and matches the the finish and profile of the barrel perfectly. Can't even tell it's a spacer unless you look really close.

Pic of the of the spacer installed:

You can see the AAC shim. I had hoped that it would time correctly without using the shims, but it would'nt.

 

[phxfa]

Re: Larue OBR and AAC Muzzle Brake not properly seated

I swear I saw a thread here or Silencer Talk on this already, I believe AAC made or make 2 different depth mounts, 1 is machined flush at the end of the mount, the other is resessed into the mount for the shim stack. the flush mount being the correct one for the OBR

 

[33shooter]

Re: Larue OBR and AAC Muzzle Brake not properly seated

I called AAC and was sent a spacer free of charge. LaRue will do the same thing.

 

[zenghost]

Re: Larue OBR and AAC Muzzle Brake not properly seated

I contacted my salesman at Larue Tactical (Sheldon) via e-mail and asked that he track down a spacer for me and send it my way.

I've sent e-mails their way before that seemingly get ignored, but I don't have time to be on hold while on the phone either.

I am doing my best to interpret this as them being extremely busy, which I understand. They did call me last Friday requesting I choose another trigger for the build as they were fresh out of SSA-E triggers. Kind of bummed me out (I chose a SSA - will sell it and buy an SSA-E), but at least it is being built from what I understand.

I do get the sense they are catching up on some orders now.

 

[SeaWolff]

Re: Larue OBR and AAC Muzzle Brake not properly seated

Update: I called Larue and talked to someone and they said they had one left so they sent out the last spacer they had. It has come to my attention that AAC may not warrant a baffle strike with a "spacer" installed. I really wanted to see that MK13 in action but it was just to much of a pain to deal with. We've got 3 OBRs and one spacer out of Larue. We had a customer service rep at AAC tell us to cut down the threads on one of our OBRs. Unfortunately the barrels on 2 of our OBRs are 16" and that would place us under the purview of the NFA act. I wouldn't do that anyway on a $3k rifle. We shouldn't have to. We weren't able to get anything out of AAC in the way of spacers but they told us to use peel washers. We had a customer service rep at Larue tell my business partner to use a crush washer which is a big no-no.
My overall opinion: I wish these manufacturers would communicate better. You have Larue, Armalite, Ruger, etc. threading their rifles at .750" and AAC is making their brakes with female threading of .620. We tried another brake on the OBR and it wasn't cooperating either. At the end of the day, I don't want to have to deal with spacers and would like to be able to just set it and be done with it. In the interest of not having any issues, we ordered 4 Surefire (3 for OBRs and one for the KAC SR-25 ECR) overlap brakes and plan on throwing some Surefire cans on. We are a Surefire dealer so it won't be too painful and Surefire makes a quality product as well. Maybe next time AAC

 

[zenghost]

Re: Larue OBR and AAC Muzzle Brake not properly seated

Agree completely. If I use a spacer, it had better be correct and acceptable by the suppressor manufacturer. In my communications with them, Thunderbeast Arms has indicated it is acceptable (they're assuming it is a precision made piece I am certain).

I have a new 16" OBR 7.62 that arrived today. I definitely have no interest in having barrel work performed on it.

I wanted the Larue-manfactured spacer if possible. Various sales people at Larue seemed to think I was looking for something that did not exist. Like it was something mysterious and exotic. That puzzled me.

I wrote an e-mail to Mark Larue. I was very polite, but expressed my concerns and desires regarding the spacer issue. Personality issues set aside (for those who have that as a concern), Mark Larue works hard at having excellent customer service. That is my experience and belief.

Within a couple days I was contacted by Mark's assistant who advised they were shipping the necessary spacer to me (a couple in fact - I had told Mark I'd probably lose one at some point). I hope to have them first of next week.

My suggestion is that Larue Tactical makes their sales people aware of both this muzzle thread-length compatibility issue and of the the availability of the appropriate spacers. With that said, I am happy with the service I received. The OBR appears to be really fine piece of work from my admittedly limited experience at this point.

 

[p951951951t]

Re: Larue OBR and AAC Muzzle Brake not properly seated

I'm wondering about the fitment of my AAC mount. It's the SCAR-H SD mount which recedes back over the barrel about 2.5", so I can't visually see if it's seated properly. I'm thinking about getting a spacer just in case.

 

[nohair]

Re: Larue OBR and AAC Muzzle Brake not properly seated

Yesterday I talked with Brent @ AAC about my 7.62SD Brake on my OBR and he had 1, but needed it to make others, I guess you can't measure and write it down. I was told it will be 2 weeks BEST case and we all know how that goes.
And my Email from him,
As for your muzzle brakes. As soon as we get the spacers made, I can ship you what you need. We have also made a fix with deep socket 762 muzzle devices, if you prefer those as an exchange. The new muzzle devices are not currently available, but they are in production cue and we should have some available soon.



And my response from Larue,Paul Payne,
We do not make a spacer - it comes from the suppressor manufacturer. The Surefire adapters we use come with the spacer. I will try and secure extras but we do not have any at this time. Call AAC.

Sales

 

[zenghost]

Re: Larue OBR and AAC Muzzle Brake not properly seated

I have received the spacers from Larue (actually they arrived first of the week). It appears to be very well-made, which I expected, and it blends with the barrel well. Does not look like any spacer or shim I've seen from SF or AAC. One interior edge has a slight bevel or chamfer (or whatever its called).

I am happy to have it as I was going to go with a custom piece from a trusted smith, but that option was going to run about $50.

 

[K_4c]

Re: Larue OBR and AAC Muzzle Brake not properly seated

I better contact Larue for mine.... Thanks for the update Zenghost.

 

[zenghost]

Re: Larue OBR and AAC Muzzle Brake not properly seated

Be persistent, go up the chain of command (if you know what I mean).

I posted the pic as evidence the part does exist! My guess is the sales staff is not aware of it - only decent reason I can think of for continually denying it exists.

 

[SeaWolff]

Re: Larue OBR and AAC Muzzle Brake not properly seated

Yep that is what the spacer I got from Larue looks like

 

[K_4c]

Re: Larue OBR and AAC Muzzle Brake not properly seated

RMBradshaw... may I ask who you talked to or possibly a number to call (or did you just contact Larue's help line?)

thanks much guys

 

[onyx1357]

Re: Larue OBR and AAC Muzzle Brake not properly seated

I wasn't a huge fan of sure fires ratchet system for their supressors. I would check them out before switching

 

[p951951951t]

Re: Larue OBR and AAC Muzzle Brake not properly seated

I sent an email to larue about the spacers yesterday. I'll update this thread with their response.


<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: onyx1357</div><div class="ubbcode-body">I wasn't a huge fan of sure fires ratchet system for their supressors. I would check them out before switching </div></div>

Why is that?

 

[SeaWolff]

Re: Larue OBR and AAC Muzzle Brake not properly seated

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: K_4c</div><div class="ubbcode-body">RMBradshaw... may I ask who you talked to or possibly a number to call (or did you just contact Larue's help line?)

thanks much guys</div></div>

I just called the general customer service. I asked for Alfred (who isn't there anymore) so the lady connected me to someone she thought could help. The guy started to charge me like $12 shipping which I said I would pay because the spacer was needed no matter what but they ended up not charging me which was cool.

 

[Outsydlooknin75]

Re: Larue OBR and AAC Muzzle Brake not properly seated

Its just another way for LaPewp to try and say he treats people better by giving them free shit. Also its another reason that until there is a spec, shit will be made however each manufacture thinks is best. Its no secret that there is no love lost between LaPewp and AAC, this is just another way to keep the feud going.

 

[GR460]

Re: Larue OBR and AAC Muzzle Brake not properly seated

This is the story I got today from Larue and AAC...Larue is no longer offering the spacer as an option. Supposedly they were getting the spacers from Surefire suppressors that were in stock but have now ran out. AAC said their fix is 6 months to a year out.

If anyone hears of a trusted option, please let me know.

Thanks.

 

[K_4c]

Re: Larue OBR and AAC Muzzle Brake not properly seated

peel shims bud.... they work just fine when installed TBAC brake.