What length for first SBR?

[joeyshoe]

I'm planning my first SBR and trying to figure out what barrel length I want/need. I have a 14.5 middy with a perm attached PWS but I plan on selling that after I get my SBR put together.

I would eventually like to also build a 18/20" rifle for longer and more precise shot placements so I want/need this SBR build to fill the role of: home defense and range toy.

I don't plan on getting a can...but we know how that goes.

The original plan was to do a sort of mk18 upper, but I am not made out of money and I feel like if I'm going to go short.... maybe I should go 7.5".

Any opinions for a SBR uber newb?

many thanks gents!
[Beer]

[islandermyk]

I believe on the FORM 1 you can put 7 inches, and your build you can add or replace any barrel length just as long as it isn't shorter than 7 inches you applied for on you application... I'm pretty sure someone will come along and correct me if I'm wrong...


... but with this method you can shoot everything in between 7 inches and as long of a barrel as you want...

Hope it all comes together for you[Beer]

[J]

You can change it out as you see fit. Any length. If it is a permanent modification, you should notify the ATF to update your registration.

You cannot sell or otherwise transfer an SBR/SBS if the current registration does not match the barrel length at the time of sale/transfer.

If you change to over 16" and still possess the parts to return it to SBR length, it remains under the purview of the ATF. If you change to over 16" and no longer possess the parts to return it to SBR configuration, you can notify the ATF and have its registration permanently canceled (tax stamp revoked) and it will no longer be under the purview of the ATF.

Standard IANAL disclaimers and such.

[J]

And to get more to the point of the OP question:

What caliber? If 5.56x45, I'm partial to the 11" with a short brake on it.

[JohnnyEgo]

7.5" is great for fun, but may take a little tuning between buffer weights and gas port sizes to get it to run reliably.

http://www.johnnyego.com/dump/rangeday4/sf7.jpg

12.5" is great all around, particularly if you are going to compete from short to mid ranges. It is my favorite length.

http://www.johnnyego.com/firearms/friends/me010.jpg

[joeyshoe]

And to get more to the point of the OP question:

What caliber? If 5.56x45, I'm partial to the 11" with a short brake on it.


I am going to stick with 5.56x45. Why do you prefer the 11"? My original thoughts were to get a 10.3/10.5 with just a birdcage I have extra. I would like to balance length (shortness) with reliability. Are the 7' SBRs harder to make reliable? I know that my middy 14.5 took a little tweaking to run lower powered rounds.

The 10.5 was appealing to me because it seems to be a popular length. To be honest, i've never fired a SBR anything and have only handled SBR AKs. Maybe I need to link up with some peeps and try some different setups.

Would the birdcage handle a 10.5 ok or should I get something more suited to a SBR? Not necessarily the Noveske KX3 because of weight/length, but something that will subdue the extra umph of the SBR.

Thanks for the help!

[joeyshoe]

http://www.johnnyego.com/dump/rangeday4/sf7.jpg



this is a major reason for my thinking in the 7 range.

I don't really plan on competing much with it. I've been thinking about doing the lake george 3 gun, but that's fairly close distances.

It seems like 10.3/10.5 may be the way to go...for me.

Is there anything bad or personal learning experiences to be said about a 10.3/10.5 barrel and a 10' rail setup? Again, no cans at this time but wouldn't mind leaving that option open. This kinda goes with my 11' large tactical gooseneck thread...if you guys didn't figure it out yet.[LOL]

hoping to get CLEO sign off and prints in a week or two. How long from send off before they cash the check? Is it still around 7 month wait?

cheers!
[Beer]

[J]

In general the shorter will be more difficult to get right. The 10.5-11.5 lengths will Be carbine length systems, instead of pistol.

Once you get to the carbine length your options open up significantly for rails, grips, etc.

And the 5.56 is a round that does very well with extra barrel to get moving.

If you said 300blk, I'd be hard pressed to not suggest a 7". Round is range limited already, and can really benefit from faster gas systems, especially on subsonics.

[asmo]

10.5 for your first.. Learn it and then start making more in different sizes shapes and colors.

[TriggerHappy]

No suppressor manufacturer will warranty a can on less than 10" barrel. I would build an sbr and keep the 14.5, why not. I really wanted a 12.5 upper to keep the velocity up, but got a screaming deal on a 10.5. Here is a pic of my first build mk18, lmt barrel and lower:

http://i39.photobucket.com/albums/e156/jake82/6fba22d2.jpg

I will be running a surefire mini once I get a sf muzzle brake/hider on it. For longer range stuff you don't really need an 18-20", unless you just want the look. 16" 1in7, good barrel, will do the trick. 223/556 loses a lot of oomph past 600yds. Here is my 16". It's very accurate with good 68gr. (could only find a family shot. Far right) DD 16" 2.5-10 vortex.

http://i39.photobucket.com/albums/e156/jake82/28db8479.jpg

[TriggerHappy]

Also, once you have the lower and form 4 done, you can have multiple uppers and calibers. Just make sure you can return it to what the form reads at all times. I want to build a 8" 300blk, 5" 9mm and a 7.5 Pdw all on the same lower.

[TriggerHappy]

I would also recommend the LLC or Trust route. And the last 4 forms took 6months +/- a week. Shoot me a PM if you have any questions.

[JohnnyEgo]

7.5" is not very forgiving. You have a very short gas tube and no real barrel to give you any dwell time after the gas block. You end up with high pressures over short distances and short periods of time, which is hard on the gun.

My first go-round with this gun was a Noveske barrel, Vltor receiver and low profile gas block, an LMT enhanced BCG, and a Vltor receiver with H3 buffer. It ran like crap. First it was short stroking. Tried swapping buffers, but that wasn't it. Plenty of high pressure, but it was bleeding off before the bolt fully unlocked. Had to swap out to a non-enhanced carrier (without the extra hole) to stop bleeding off the gas. Then I had bolt bounce. H3 was too heavy, H was too light. Had to go with an H2 to get it to run reliably on cheap 55gr XM193.

I know a bit about ARs, and I have friends who know a lot more about them then I do. I also worked in a gun shop and range with a ton of parts to swap in and out, so none of this was insurmountable. They also wisely kept me from just drilling the gas port. The point of all this is that the shorter you get, the more of a crapshoot things are. Maybe everything works out just fine. Or maybe you end up constantly adjusting a thousand things at some expense until you get frustrated or broke.

If this is your first SBR, and you are going to build it yourself, I'd highly recommend sticking with a more common length. 10.3 is fine, 11.5 is better, 12.5 is the most forgiving.

And to shill for the man I was impressed with locally, Bert of BPTactical does a hell of a job cutting and properly threading barrels.

I don't know Colorado geography very well as a newcomer, but if you are ever up in the Greeley/Windsor/Ft Collins area and you give me enough notice, I can probably let you try a couple different ARs with short barrels and you can get a feel for it yourself.

The super obscure 9.5":

http://www.johnnyego.com/firearms/ars/morears2/ubrvisc.jpg

[Great-Kazoo]

I did a 14.5 first the went to a 10.5 with AA piston system. I might do a 12 or 12.5 OR go back to a 14" with AA piston, decisions, decisions.
The 7" dedicated 22lr and 10" 9mm enjoy their time on the range too.

[Mick-Boy]

FWIW - The 7in (carbine) gas system was originally for the Colt Commando during Vietnam. What Colt (and the military) found during field testing was that the 11.5in barrel was more reliable than the 10in barrel it was originally issued with. That's the length Colt Commandos are built with today.

Can you get a shorter barrel to run? Hell yeah! My first SBR was/is a 10.5in that has 25K rounds through it and still runs fine. One of my work guns in an 8in. However, as other people have mentioned, they will require more tuning and more parts maintenance (the shorter you go the more the gun will beat up its parts when it cycles).

My advice for a first SBR would be 11.5 in. It's short enough to be handy and is easy to make run. Buy one from a quality manufacturer (LMT, BCM, Etc) and you should just be able to plug and play.

As far as muzzle devices go, I don't believe the 5.56 round in any configuration has enough "umph" to make one necessary. If you try one and decide you like it, cool. But I don't think you need to "plan" on dropping an additional $100+ on a muzzle device to make the gun shootable.

[mahabali]

My 7.5" did take some tuning but shoots like a champ now. I did the 7.5" first because I wanted a fun gun. It is actually more accurate than you might think with the 7.5" Noveske Diplomat barrel.

My next will be a 10.5" so I can get a can.

http://i1222.photobucket.com/albums/dd485/mahabali/IMG_2154.jpg

http://i1222.photobucket.com/albums/dd485/mahabali/IMG_2152.jpg

[Gunoholic]

I see "barely used" 10.5" lmt uppers for sale pretty often. I got mine with a sure-fire quad rail and bcg for right at $500 of gunbroker. I love it.... and im my opinion a 10.5 is just as "cool" as a 7".

I added a battle comp 1.0, and it runs great..... a lot less snappy than the A2.

[hatidua]

I started with a 10.5" LMT upper and regret selling it a few months ago, -the thing refused to fail, no matter the buffer/ammo/suppressor, it just never had a single hiccup no matter how hard I tried to make it cough.

I now have a BCM 11.5 upper which runs just as well. I only replaced the LMT upper to reduce wear/tear on my suppressor. If a suppressor isn't in the picture, an LMT 10.5 is a pretty good value and has been mentioned above, finding them used on various for-sale boards is fairly common.

When I switched from the 10.5 to the 11.5 upper, I sent a letter to ATF and laminated a photocopy of their return acknowledgement of the length switch that I keep in my range bag.