View Full Version : Building an SBR - what barrel length?
I'm trying to decide what barrel length would be optimal for my SBR build.
The gun will be my home defense rifle, but I would also like to to be effective at the range out to 75-100 yards or so. What do you guys think? I'm just going to have my current M4 barrel cut down by ADCO. I'm running a CAR gas system.
Jay Cunningham
07-30-09, 08:45
No shorter than 10.3" - I prefer an 11.5" myself.
CAR-AR-M16
07-30-09, 09:31
I like the 12.5" Operator barrel from Dennysguns/GTS.
VooDoo6Actual
07-30-09, 10:33
"10-13" will work nicely for you.
HTH
No Bananas
07-30-09, 11:34
"10-13" will work nicely for you.
HTH
This is the range to go for. Any longer IMHO isn't worth the $200 and registration. Any shorter than 10" will usually result in function issues, and certainly result in severe velocity loss. The fireball and blast are fun though...unless you're the guy next to you :D. I think the best compromise is 11.5". Of course, our advice would be to get a 10, 11.5 and a 12.5.....maybe (2) 11.5":D
I vote 11.5... It should do what you want.
I held one the other day and it was real short and maneuverable... very nice indeed!
11.5
I have 2 of those in my weapon stash.
At least 10.5 to stay alive!
Cameron
11.5
10.5 is theoretically less reliable, although real world reliability is fine.
10.5 is harsher on silencers.
I would suggest on either 11.5" or 12.5". You wont loose a lot of velocity compared to a 16".
Going lower than 10.5" sometimes gets a little finicky when troubleshooting on a Failed to Extract, Failed to Cycle or Failed to Feed. This is what happened to me with my 7.5"
G-luck. I hope your project goes well :)
I really like the look of the 10.5" barrels. As far as reliability with a DI CAR gas sytem, what's the consensus? Is a 10.5" SBR one application where a piston conversion actually makes sense?
Jay Cunningham
07-31-09, 09:05
Is a 10.5" SBR one application where a piston conversion actually makes sense?
IMO no. A piston gun only "makes sense" under a certain set of circumstances, and simply running a 10.5" barrel isn't enough justification.
Ok thanks for the input. Do you think the gas port may need to be opened up a bit? I'm having a 14.5" cut to 10.5" once the stamp comes back.
IMO no. A piston gun only "makes sense" under a certain set of circumstances
RIGHT! When the gun is an AK. :cool:
Jay Cunningham
07-31-09, 09:44
RIGHT! When the gun is an AK. :cool:
lol1!!1
One thing that isn't quite clear to a lot of people is that suppressed AKs get *real dirty* and it would behoove the end-user to keep them *well lubed*.
OMGZ!11! :eek:
No Bananas
07-31-09, 10:03
I really like the look of the 10.5" barrels. As far as reliability with a DI CAR gas sytem, what's the consensus? Is a 10.5" SBR one application where a piston conversion actually makes sense?
My 10.5" LMT DI has never jammed, and I've shot all types of ammo through it. You don't even need to do the H (H2, H3, etc.) Buffer thing. Functions perfectly w/ a carbine buffer. No bounce, no jams, no problems. As long as you stay with a quality build, which is worth every penny, you'll be more than fine w/ a DI 10.5". Stick w/ LMT or Noveske.
**Also get a quality BCG (again, worth every penny).
Have Fun!!
Ok thanks for the input. Do you think the gas port may need to be opened up a bit? I'm having a 14.5" cut to 10.5" once the stamp comes back.
I'd buy a factory 10.5" barrel instead. What you want to do is too much fooling around.
My 10.5" LMT DI has never jammed, and I've shot all types of ammo through it. You don't even need to do the H (H2, H3, etc.) Buffer thing. Functions perfectly w/ a carbine buffer. No bounce, no jams, no problems. As long as you stay with a quality build, which is worth every penny, you'll be more than fine w/ a DI 10.5". Stick w/ LMT or Noveske.
**Also get a quality BCG (again, worth every penny).
Have Fun!!
This gun should have atleast have an H buffer.
I'd buy a factory 10.5" barrel instead.
Seems like a waste of money . . . . :confused:
decodeddiesel
08-03-09, 16:12
Seems like a waste of money . . . . :confused:
Why? Having a barrel chopped introduces a lot more risks and chances for damage than a factory LMT or Noveske barrel. The gas port will be tuned correctly, the chrome lining won't have the possibility of being damaged in the chop, and you usually will have factory warranty support if something doesn't work right (which often does not).
NFA is not a poor man's game. You have to pay to play.
I'd like to build an 11.5 with a Noveske Switchblock. I'm wondering if you can purchase the barrel w/Switchblock installed from Noveske. Or, just a complete upper with a Switchblock. Thanks for getting me thinking; that just means more $$$ spent eventually.:)
Seems like a waste of money . . . . :confused:
It is going to cost you $150+ to cut down a barrel, open the gas port, and have it refinished. Then you will be left with a barrel that was originally $300 and is now worth $125 and is non factory.
You can buy a factory barrel and sell your other one and break even.
If I already own a lower, and want to build it into a SBR; can I then go through the NFA process? Or do I have to do it at the time of purchase of the lower?
Why? Having a barrel chopped introduces a lot more risks and chances for damage than a factory LMT or Noveske barrel. The gas port will be tuned correctly, the chrome lining won't have the possibility of being damaged in the chop, and you usually will have factory warranty support if something doesn't work right (which often does not).
NFA is not a poor man's game. You have to pay to play.
It would go to ADCO, who test fires all uppers and does any required gas port work.
Thanks for the condescending reply, though. :rolleyes:
If I already own a lower, and want to build it into a SBR; can I then go through the NFA process? Or do I have to do it at the time of purchase of the lower?
An ATF Form 1 is used to convert your existing lower into an SBR. You will have to have your name and city engraved on your current lower.
If you don't wish to engrave your current lower then you'd need to buy a lower already registered as an SBR from a Class III dealer. This would require a Form 4 (and possibly a Form 3), potentially making the wait time longer than simply going with a Form 1 on your existing lower.
decodeddiesel
08-04-09, 09:47
It would go to ADCO, who test fires all uppers and does any required gas port work.
Thanks for the condescending reply, though. :rolleyes:
Wow, condescending? Are you serious?
Sir if you don't like what other have to say, or are looking for immediate gratification of your foolhardy decisions then why bother posting? Further if you felt that was a condescending post then perhaps the internet (and especially this forum) is not the place for you until you grow some skin.
Do whatever you want with your upper, I could really care less. It's just that some of us have been down these roads before and are trying to share our experiences with others who haven't so they don't make the same mistakes we did. That's the whole point to this forum.
It would go to ADCO, who test fires all uppers and does any required gas port work.
Thanks for the condescending reply, though. :rolleyes:
ADCO is not going to troubleshoot your entire setup with different buffers, extractor springs, test with a silencer, etc. It is unreasonable for them to do this.
All they would do (and would be expected) is maybe fire 10 rounds through your upper.
What brand of barrel do you have now?
Wow, condescending? Are you serious?
Sir if you don't like what other have to say, or are looking for immediate gratification of your foolhardy decisions then why bother posting? Further if you felt that was a condescending post then perhaps the internet (and especially this forum) is not the place for you until you grow some skin.
Do whatever you want with your upper, I could really care less. It's just that some of us have been down these roads before and are trying to share our experiences with others who haven't so they don't make the same mistakes we did. That's the whole point to this forum.
The insinuation that I was a "poor man" and therefore couldn't play the NFA "game" was condescending. I've had BRD long enough to know the drain it makes on the bank account. ;)
What brand of barrel do you have now?
LMT. Complete LMT M4 upper.
The insinuation that I was a "poor man" and therefore couldn't play the NFA "game" was condescending. I've had BRD long enough to know the drain it makes on the bank account. ;)
You are getting worked up over nothing.
Your position of not wanting to replace the barrel came off as you being very cheap. This position is what the amatuer uses.
Cutting a barrel down is only used for very, very specific custom builds where a factory barrel is not avaliable as an option.
LMT. Complete LMT M4 upper.
Then I would just buy the LMT 10.5" upper or barrel and be done with it.
Why would you cut one down when you can buy a factory one that will get you to exactly where you want to be?
Here is what Bravo Company said about why they choose to go with 11.5" uppers:
"Q: Why BCM chose the 11.5" SBR over the 10.5"
I get this question a lot. It is a good one. When we spec our program we can build anything we would like, so we sat down and looked at the pros and cons.
First Statement: I know a good 10.5" SBR can run very well. I personally own a semi MK18 type and it runs great. No problems.
A: Dwell time.
Dwell time is the time that your gas operated weapon maintains pressure to continue the cycling of the weapon. It primarily exsists from the time the bullet passes the gas port in the barrel to the time the bullet exits the muzzle. When you pull the trigger and fire the weapon the movement of the bolt carrier group unlocks the bolt, extracts, and ejects the spent casing. Then it cocks the weapon, feeds, chambers the next round, and then locks again. One of the thing that can make SBRs finicky is the dwell time (or lack of).
The 11.5" carbine is approximately 4% longer weapon than its' 10.5" counterpart, but this extra inch gives the barrel a 40% increase in length for dwell time. IMHO, this is an excellent trade off. This additional dwell time (all other things being equal) will allow the carbine to be more forgiving to different ammo types, extremes in air temperature, weak or worn extractor springs, worn extractors, buffer weights, etc.
Last Statement: For those folks who have a 10.5" that works very well, I would reply; me too. (see first statement)
If I had to "go to war" with a AR15 Carbine, I would grab the BCM 11.5".
The BCM 11.5" Runs Like a Dream.
Hope this info helps,
Paul "
Powered by vBulletin® Version 4.2.5 Copyright © 2024 vBulletin Solutions, Inc. All rights reserved.