Barrel lengths on SBR

[Winmagbill]

Have a braced pistol lower that I’ve been thinking of going SBR ever since I got it. Always wanted a forearm grip but it wasn’t worth the hassle and $200. Now I’m back on the fence.

Here’s my issue can I have one SBR lower but have 2 uppers of different caliber or assembled overall length? (Barrels 10.5” and 7.5” for example)

Always heard No. With the new rules is it different?

 

[ducatilover]

Yes you can. New rules are for the brace. Swap away!

 

[Winmagbill]

Good news, thanks.

 

[muta4warrior]

For AR's, I always put what whatever length barrel is going to live on the lower the most on the Form 1, 2 push pins and you can swap to another barrel.

 

[mock0013]

actually put the shorter barrel on the Form 1. you can have a longer on it but not shorter was what my dealer had me do. it's just a letter to them if you need to change it later

 

[delta6]

actually put the shorter barrel on the Form 1. you can have a longer on it but not shorter was what my dealer had me do. it's just a letter to them if you need to change it later

And only if the barrel change is permanent.

 

[mock0013]

actually put the shorter barrel on the Form 1. you can have a longer on it but not shorter was what my dealer had me do. it's just a letter to them if you need to change it later

And only if the barrel change is permanent.

I was assuming more that you have 2 complete uppers versus swapping out barrels on an upper. Easy to switch to whatever was put on the paperwork. if you decide to sell the one listed on the paperwork, yeah you have to update the ATF with new overall length.

 

[mock0013]

Becareful if you have two different caliber uppers, ideally your lower needs to say multi-caliber not just 5.56. this way you can use your 300blackout and 5.56 upper or whatever combo. But you need to list the lower as multicaliber

Notice on the Spikes lower it say Cal- Multi ... that engraving for caliber goes on your Form 1.
if it's a true stripped lower aka pistol it should be like this.

You don't want one like this PSA (not all psa are like this) and notice it says m4 Carbine

 

[Winmagbill]

actually put the shorter barrel on the Form 1. you can have a longer on it but not shorter was what my dealer had me do. it's just a letter to them if you need to change it later

And only if the barrel change is permanent.

Not making a permanent change. Permanent is a 7.5" 556 but like to toss on a suppressed 10.5" 22lr upper for fun. With a braced pistol that's all good. Want to confirm it's the same with an SBR. Plus bonus stubby forearm grip.

 

[campinginaz]

Becareful if you have two different caliber uppers, ideally your lower needs to say multi-caliber not just 5.56. this way you can use your 300blackout and 5.56 upper or whatever combo. But you need to list the lower as multicaliber

Notice on the Spikes lower it say Cal- Multi ... that engraving for caliber goes on your Form 1.
if it's a true stripped lower aka pistol it should be like this.

You don't want one like this PSA (not all psa are like this) and notice it says m4 Carbine

Thank you for posting this. I've been thinking of building an AR platform SBR so I could swap uppers/mags to shoot different calibers. I haven't bought anything yet so this very well might have saved me some money!

 

[delta6]

Becareful if you have two different caliber uppers, ideally your lower needs to say multi-caliber not just 5.56. this way you can use your 300blackout and 5.56 upper or whatever combo. But you need to list the lower as multicaliber

Notice on the Spikes lower it say Cal- Multi ... that engraving for caliber goes on your Form 1.
if it's a true stripped lower aka pistol it should be like this.

You don't want one like this PSA (not all psa are like this) and notice it says m4 Carbine

"Multi" has not been accepted by the ATF since 2015. You have to designate a caliber on your form 1.

 

[mock0013]

Damn now I feel old... so how do you deal with AR lowers that can take different caliber uppers?

[/quote]
"Multi" has not been accepted by the ATF since 2015. You have to designate a caliber on your form 1.
[/quote]

 

[QuietM4]

As long as the SBR can be reconfigured to it's original Form 1 condition, e.g 7.5" 5.56mm, you can do anything you want. Have a 12.5" 300 Blackout upper, a 7.62x39 14" upper, a 6" 22lr upper, etc, etc...