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SBRcarbon15 01-13-2009 07:30 PM

new guy with questions!
I'm new to the forum, so "Hi" everyone. I'm glad forums like this are around, I've been reading posts for a few hours now and I thought of a question I haven't been able to search.
I recently purchased a bushmaster carbon 15 pistol, 5.56mm. 7.25"bbl
I called up bushmaster to see if it was a good idea or not to install a AAC suppressor I have for another AR. I wasn't expecting him to say "go ahead", due to the short gas system and increased back pressure or the can, my question is this:, has anyone tried shooting the pistol version with a sound suppressor, and will it destroy my new toy?

Dillinger 01-13-2009 07:46 PM

First Welcome to the Forum -

Assuming you have all the legal paperwork in place, just to cover the Forum here should any of the Feds be wandering through.....

Are you running full power loads, or are you running subsonics through the AAC in the other model?

If you are running subsonics, You have to keep in mind that you have to derate the round for the barrel length for the can to work correctly.

I haven't personally tried it, but it would stand to reason that a full pressure round, in a short barreled, AAC attached would indeed cause excess pressure for the amount of time it takes for the pressure to dissipate out the end of the can. Since the pistol version is a much shorted stroke, I would say yes, it COULD cause problems under sustained fire.

One or two rounds here or there I don't believe is going to ruin it - assuming you are using full power loads.

With subsonics, if you derate for the length of the barrel, which is essentially determining how much pressure will be generated, I would imagine you could shoot all day without a hiccup....

Let us know what you find out - I would be curious to know as well.


matt g 01-13-2009 08:38 PM

My main concern would be for the Carbon 15's odd receiver materials. I'd hate to see you blow apart your over priced, plastic AR pistol.

Bushy is becoming a driving force in the AR market. I don't see why they wouldn't be able to provide you the info on what your target pressure would be. I'd bet money that at least 10% of Bushmaster's rifles and carbines have cans stuck to the end of them.

canebrake 01-13-2009 08:57 PM SBRcarbon15

Glad to have you aboard and see you are already answer mining! That's what we're about.

I will defer your question to those in the know about those evil black rifles. My choice is the brown eastern Europe 7.62x39 type.

With that said, my engineering thinking would be to check with the suppressor maker and see if your 'can' is the recommended part for the new pistol. If not, and they have another part number for the new gun my guess would be don't use it.

Nuff said. Let the others help sort it out.

robocop10mm 01-13-2009 09:23 PM

Consider a heavier buffer. An H-2 would probably be a good idea, maybe an H-3.

SBRcarbon15 01-14-2009 10:55 PM

thanks for the replies guys, and the welcome. Well, AAC is located in GA as I am, and I tried getting them on the phone today, to no avail. I'll try again in the morning. My 5.56 suppressor is a Ranger 2 model. I'll have to machine a bushing to cover about 1/4" of threads on the pistol's barrel so the suppressor can screw down tight (it bottoms out due to the length of the threaded section). If AAC confirms that the gun will function suppressed I will post with the results. I'm due in Fl tomorrow and will be back sunday to start tinkering, until then, thanks again.

also to answer questions,
I am running full power 55g FMJ.

I will look into heavier buffers. (the stock pistol has a different bolt carrier and buffer than common AR's. but mine is SBR, and has been converted to a "normal" AR buffer system)
I do have a tax stamp for all of my suppressors, and for this SBR.

Dick Manley 01-24-2009 05:05 PM

The carbon bushy's do not run reliably with suppressors, also another thing to think about, that your barrel burn out will be much faster when using a can on a sub 10" bbl.


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