Barrel Length for My New SBR Build

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SilverCat

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I'm in the process of deciding what length to make my .300 Blackout SBR, and I was thinking 6 inches. I plan on suppressing this rifle. This short length won't damage the suppressor, will it?? AAC, the company that pioneered the .300 Blackout cartridge, developed the Honey Badger with a 6 inch barrel I believe. Thanks all.
 
I would contact the manufacturer of the can you plan on using and ask them of any restrictions. 6 inches sounds pretty short. While it may work a little longer barrel will likely give greater reliability with little impact on the overall package.
 
Personally I wouldn't go for 6 inches.
I have a number of SBRs. I once had a 4" barrel on a Ruger 10/22.
The "rifle" doesn't feel right, doesn't handle right.
And, if we are talking about a centerfire rifle, you are losing a lot of ballistic effectiveness.
I don't see why it would damage the suppressor, but I think you would be happier with something at least 10 inches. 12 inches seems like a nice length to me.
If you are doing this on an AR15 platform, changing the barrel out is easy as is having multiple uppers.
 
The feel is fine, as I'm planning on suppressing it and shrouding most of the can with a forend. My concern is that the powder won't burn up fast enough and may damage the suppressor. Just as a 5.56 shouldn't be suppressed if it has a barrel under under 10.5 inches (maybe 10.25??). I just need to know how fast a .300 whisper is designed to burn up.
 
I've moved this to our NFA items forum. I think you'll get better answers from the stamp collectors who hang out here.
 
I would not go below 8". I'm using a suppressor designed for .308 so I'm not worried. You will have more pressure, heat, and unburned powder abrasion the shorter you go but you should ask your manufacturer.

I'm going 10.5". I don't even have parts yet as I was not expecting my stamp for a year or so when my E-form 1 came back in 91 days!

Mike
 
I agree with Mike. 8" is the shortest I'd go. And I opted for the 9" AAC barrel for my .300AAC build. With a 762-SDN6, it will still be a hair shorter than a traditional 16" AR.
 
8" seems to be a fairly standard barrel length for .300 AAC. That's what I would recommend going with.

I have 6.5" barrel on my .300 AAC short-barreled AR. But I've also had some issues with cycling. It should cycle subsonics just fine with a suppressor mounted. (I'm still waiting on my suppressor stamp to arrive.) However, it will not cycle subs without a suppressor. And it will cycle supers, but I did have to open the gas port up to the max size.

The potential issue that you're running into with a barrel that short is that 6.5" plus a pistol length gas system means you've got hardly any barrel after the port. That's a short dwell time. I think that AAC may have used a shorter gas system for the honey badger. If you have that capability, go for it.

So stick with 8"+ if you want no fuss. If you just have to have shorter, then I know that 6.5" will work. But it will also be finicky.

Aaron
 
Thanks for the responses. My goal is simply to make the smallest possible package that one can shoot without ear protection if they wanted. I guess I can go up to 8".

Aaron Baker, it does sound like the 6.5 has issues. Is there any damage to the suppressor??
 
No idea. Still waiting for the suppressor tax stamp to arrive so I can pick it up and install it.

I don't expect damage, but I would guess that there will be faster wear on the blast baffle.

Aaron
 
Oh. I was under the impression that you had it. Thanks.

Do the e-forms go quicker than a mailed form?? If so than that sounds very much easier.

Also, on the form 1 on overall length, does that mean with extended stock, or not extended?? Thanks!!
 
eForms for the Form 1 are quicker, but you must be using a trust. Individuals can't use eForms because they must still submit fingerprints and photographs. You can only use eForms for Form 4 if your dealer is set up for it, since they submit the form.

SBRs are measured with the stock extended.

Aaron
 
mine is 8", cycles fine with subs suppressed and unsuppressed. by the time you hit 8" (or maybe its 9") all the powder should be burned in the supersonic ammo.

this round is much different than the 5.56 and therefore doesnt have the same erosion issues that 5.56 produces with unburned powder in a short barrel.


i use 8" for my 300 BO
i use 11.5" for my 5.56

those are my preferences but i feel i have a lot of reasons and back-up to use both of those lengths.
 
Thanks for the info Charger. I believe I've decided on 8". That's not to long, an I may go with a shorter suppressor.

I do in fact have a trust set up. It was notarized this very day actually. THANKS ALL!!
 
Goodness. I guess people must really like their barrels. I've heard that Daniel Defense make the very best, is that true??
 
In my research of 8" and 9" barrels, Noveske and AAC got the most praises for highest quality, accuracy, and reliability. I don't know anything about DD's Blackout barrels specifically, but all of their products that I've encountered have been very nice.
 
I see where you are coming from and did the same evaluations, but I decided I don't like reloading enough to get into .300Blk at this time. So instead I've ordered a 5.5" 9mm barrel, being blowback no gas port location issues. I've got everything I need (stamp included) except the barrel, back-ordered :(

My 9mm can is rated for .300Blk subsonic so it wasn't much of a factor in the decision. I already reload lots of 9mm 147gr ammo.
 
I have a 9" for my AAC .300 BO and a 10" for my DD .223 uppers. An inch or two doesn't really make a whole lot of difference in this range, but going below 8" doesn't make much sense to me, IMHO.
 
Good luck with the 8.2 Noveske those things are like gold right now. Every time they come in they sell out in a hour or so. I had to pay over retail to get mine about 6 months ago. I am now looking for a 10.2 and they are even hard to find out there.

As stated above me a 9 inch would work also and have heard good things on the KAK Industry barrels they are only 260 I think for the 9 inch model.

Good luck with the Blackout it is a sweet round!
 
late to chime in here but there is a company out near Houston that does a 6" 300BLK barrel... That said, the shortest I've ever seen from AAC is an 8.2" barrel. If there was anything to gain from a shorter barrel they, or one of the other big players would be selling it.

I think I'd go with what the folks who developed the SAAMI-spec version of this round build.






Unless you really like 2-foot fireballs out of the end of your SBR! ;)
 
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