I just got  my stamp in and now I'm ready to purchase a new upper.  I've got a Gem Tec M402 on the way which I intend to use with this rifle.

I'm not sure if I want to go with a 14.5" barrel or an 11.5" barrel.  I think the 11.5" barrel will be more compact with the suppressor mounted but I understand that it will be significanly louder than the 14.5" barrel.  

The longer barrel will give significantly better ballistics.

So for a 1st SBR AR what barel length would you go with and why?

If it was me, I'd go with the shorty.  If you were concerned about ballistics, put a 20" barrel on a Title 1 lower.  

I would have a difficult time justifying the added expense and hassle to register an SBR, just to put a 14.5" barrel on.  I can't see going through all that, when I could get a barrel that is 1.5" longer and avoid it.

Shorter looks better anyway.

I can't see going through all that, when I could get a barrel that is 1.5" longer and avoid it.

Or get a 14.5" barrel and permanently attach a Phantom.  Or get a 14.7" barrel and permanently attach an A2.  Etc.

Quoted: I can't see going through all that, when I could get a barrel that is 1.5" longer and avoid it. Or get a 14.5" barrel and permanently attach a Phantom.  Or get a 14.7" barrel and permanently attach an A2.  Etc.

Exactly.  If you want a 14.5, get an M-forgery.  If you're going to register / build a SBR, build a short-barreled rifle.

go with a 10.5" and put the can on it. it won't be TOO loud but it will be nice and compact.

11.5" is my personal preference for 5.56 SBR.

There is some research or something floating around about a 10" barrel being the minimum requirement for the .223, to get the speed and tumbling effect that you need for lethality. If you want to buy into that then I'd suggest the 10.5" barrel with a flash supressor on the end. I have a 9.5" barrel on my SBR and love the thing. The size is fantastic for moving it around. But one more inch would cause too much trouble... I think.



If you make and register an SBR, you need to make it an SBR.

What length did you put on the paperwork?

Quoted: What length did you put on the paperwork?

U read my mind.

the suppression difference between a 14.5 and a 11.5 is not  THAT big, especially with a quality can.

i'd go with the 11.5, or my personal favorite 12.5 (because I can mount my surefire on the 12.5" )

Origionally  I put 11.5" and 14.5" in the barrel length box and .22lr, 9mm, 5.56 in the caliber box. That was rejected with instructions to put only one barel length and one caliber on the form.  I put 5.56 in the caliber box and 14.5" in the barrel length the second time which was approved.

The can is a Gem tech m4-02 which is pretty compact itself.

I'm leaning on 11.5"

Quoted: Origionally  I put 11.5" and 14.5" in the barrel length box and .22lr, 9mm, 5.56 in the caliber box. That was rejected with instructions to put only one barel length and one caliber on the form.  I put 5.56 in the caliber box and 14.5" in the barrel length the second time which was approved. The can is a Gem tech m4-02 which is pretty compact itself. I'm leaning on 11.5"

Well if you put shorter barrel on it U might get in trouble. If U get caught. But who knows if they enforce this or not. In the past it was ok. Somewehre it says if U alter the gun U will need to send a form for that. Dont know which one U need or were it is posted at.

I've heard that too but so far I've been unable to find any arrests let alone successful prosecutions for haveing a lawfully registered and engraved SBR with a barrel length other than that on the form.

Does Gemtech ok the M4-02 for use on a 10.5?  I have a 10.5 and need a can for it.

Quoted: I've heard that too but so far I've been unable to find any arrests let alone successful prosecutions for haveing a lawfully registered and engraved SBR with a barrel length other than that on the form.

If you make a permanent change to the barrel length, you're supposed to notify ATF in writing of the change.

If you build anything other than a 14.5" SBR as a first pass, you're coloring outside the lines, at least a bit.  Will it matter or will you get caught, who knows?  Given the stakes, I'd rather not find out.  Of course, you've also just admitted it on a web forum known to be monitored by BATFE.  

I doubt you'll find anyone prosecuted for it.  But ATF has also been known to just seize the contraband weapon, destroy it, and call it a day.  You don't get prosecuted, but you're still out the value of that weapon.

The reason your first form got rejected is that ATF doesn't consider a form 1 to be a permission slip to build whatever you want.  It is a registration to built a particular configuration of NFA weapon, which is why all those details should be known, and are required to be specified, in advance.

Just some food for thought.

If you build anything other than a 14.5" SBR as a first pass, you're coloring outside the lines, at least a bit. Will it matter or will you get caught, who knows? Given the stakes, I'd rather not find out. Of course, you've also just admitted it on a web forum known to be monitored by BATFE

If the BATFE wants to waste their $$ and reputation trying to prosecute someone for possessing a SBR after they approved said person to construct a serialized SBR then we as a nation of gun owners are done for.

Quoted: Does Gemtech ok the M4-02 for use on a 10.5?  I have a 10.5 and need a can for it.

When I first got into SBR's I was told that most can makers will not warranty their product if used on a barrrel length less than 11.5 due to higher probability of baffle strikes & other issues with barrels under 11.5. This is what the major class III dealer in my town we all go to has stated as well. That may be true, but you know how gun counter & range talk goes. I dunno for sure, but I haven't talked to any can company rep yet to confirm this & haven't noticed such a policy on any of the major can makers web sites yet either. Obviously you see many cans on 9/10.3/10.5 SBR's on this site & the owners have all stated their cans work fine on these guns...at least none have admitted the contrary if they didn't work well anyway.

Quoted: If you build anything other than a 14.5" SBR as a first pass, you're coloring outside the lines, at least a bit. Will it matter or will you get caught, who knows? Given the stakes, I'd rather not find out. Of course, you've also just admitted it on a web forum known to be monitored by BATFE If the BATFE wants to waste their $$ and reputation trying to prosecute someone for possessing a SBR after they approved said person to construct a serialized SBR then we as a nation of gun owners are done for.

Thank you, John Adams, for your stirring speech.  

How about prosecuting him for perjury for lying on a government form?  

It's pretty simple, the application he filled out stated 14.5" for the barrel length as the length he intended to use on the SBR he applied to build.  Right above his signature it says, "Under Penalties of Perjury, I Declare... it is true, accurate, and complete...."  Putting an 11.5" barrel on his new SBR makes that application no longer accurate.  Is that splitting hairs?  Sure it is.  But ATF has taken many chickenshit positions over the years and they back up those opinions with felony convictions.  That is a game I don't wish to play, ever.

The whole reason that ATF no longer accepts "<16 inches" as a barrel length on a Form 1 is that they expect you to build a specific rifle with a specific barrel length.  It isn't an open-ended permission slip to do whatever you want after you get the stamp.

Personally, I don't care what he does.  Not my weapon, not my problem.  If it gets confiscated, I don't care.  If he ends up in prison, I don't care.  The only lesson one needs to take away from all of this is figure out this shit BEFORE you complete and send off a Form 1, not afterwards.  Life is a lot simpler that way.

And once again, it is unlikely that BATFE would prosecute over it anyway.  But them calling the weapon contraband and them giving you the option of surrendering without prosecution is hardly a "win" for him either.  Why even go down that road?

Figure your shit out, THEN fill out the paperwork, not the other way around.

Thank you, John Adams, for your stirring speech. How about prosecuting him for perjury for lying on a government form? It's pretty simple, the application he filled out stated 14.5" for the barrel length as the length he intended to use on the SBR he applied to build. Right above his signature it says, "Under Penalties of Perjury, I Declare... it is true, accurate, and complete...." Putting an 11.5" barrel on his new SBR makes that application no longer accurate. Is that splitting hairs? Sure it is. But ATF has taken many chickenshit positions over the years and they back up those opinions with felony convictions. That is a game I don't wish to play, ever. The whole reason that ATF no longer accepts "<16 inches" as a barrel length on a Form 1 is that they expect you to build a specific rifle with a specific barrel length. It isn't an open-ended permission slip to do whatever you want after you get the stamp. Personally, I don't care what he does. Not my weapon, not my problem. If it gets confiscated, I don't care. If he ends up in prison, I don't care. The only lesson one needs to take away from all of this is figure out this shit BEFORE you complete and send off a Form 1, not afterwards. Life is a lot simpler that way. And once again, it is unlikely that BATFE would prosecute over it anyway. But them calling the weapon contraband and them giving you the option of surrendering without prosecution is hardly a "win" for him either. Why even go down that road? Figure your shit out, THEN fill out the paperwork, not the other way around.

So by this line of thought, as long as I have the 14.5" barrel in my posession I can put any length barrel on the regisetered SBR lower as I'm not manufacturing a new lower as I was when I built the first SBR.  

If you put the 14.5" on the first time you assemble it, you've made your 14.5" SBR and the job is done.  You're then free to put whatever upper you want on it, of whatever length.  If the change is permanent, you're supposed to notify ATF of the change.  So you send off a letter to the NFA Branch telling them your SBR, serial number XXXXXXX, is now permanently wearing a 11.5" barrel and for them to note the change in the Registry.  You send two copies of this letter and ask them to stamp one copy and return it to you, which you then keep with your Form 1 paperwork.  The 14.5" barrel can then be sold off of whatever.

Yes, it is a lot of BS hoop-jumping, I fully admit, and some may call me overly paranoid.   But given the stakes of the game (loss of a very expensive weapon at minimum or felony prosecution at maximum) I just see no reason to play even remotely outside the rules.

Theoretically, one could build just install the 11.5" barrel the first time around, send off the letter mentioned above, and that whole operation would fall well inside the realm of "who's gonna know?"  Since that might be a criminal act, the CoC prevents me from advocating any such activity.  

Good luck with whatever path you choose and, as usual, post pics of the finished product.  Gun porn is always welcome.  

Remember the key is phrase is "permanent change".  If you had it registered in 14.5 thats great, just never sell the original 14.5 when you buy your new 10.5 or 7" Kitty Kat upper.  Thay way you are never technically making a permanent change to the rifle.  It would IMHO show intent to make a "permanent change" if you registered it with a certain length barrel and then got rid of it only to get a shorter upper while never retaining the original upper.  If you want to be real paranoid, bring all your uppers to the range with you in case you run into the man.  That will really freak them out.  In my experience, most LEO's leave you alone after they see your paperwork only to ask you if they can shoot it.