About to start my sbr build in 300 blk..

[Colten519]

I'm about to start a sbr build for a 300 blk and eventually put a can on. Any advice, recommendations, warnings and all other info would be appreciated.

Thanks
Colten

[dallasb]

It's just like any other AR. My main recommendation is to make sure the barrel has a pistol length gas tube.

Make sure you buy a quality barrel and check concentricity when you suppress it.

Do you reload your own ammo?


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[Colten519]

Ok thanks. Yes I plan too. I'm working up loads right now for my brother in laws suppressed 300 blk

[dallasb]

Originally Posted by Colten519

Ok thanks. Yes I plan too. I'm working up loads right now for my brother in laws suppressed 300 blk

Something you may want to check is whether your state allows for SBR hunting. I know my state allows suppressors but not SBRs (I know it's dumb, but not willing to tango with the game wardens). I know you posted earlier about 300blk hunting bullets, just don't want there to be any issues for you.

I've put quite a bit of plinking ammo through my SBR, most of it has been a coated lead bullet as they are cheap and I mostly shoot subsonic/suppressed.


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[Colten519]

Thanks for the heads up. Yes I'm in Texas and we can

[TMD]

Forgot the upper for now. Pick a quality lower you'll like for a lifetime considering he stamp is 4 times the price of some lowers.

[Colten519]

That's what I'm planning on. And while it's getting engraved I'm gonna go ahead and get them to put a custom logo on for me. Luckily ident marking is like 5 min from my house

[dallasb]

Originally Posted by Colten519

That's what I'm planning on. And while it's getting engraved I'm gonna go ahead and get them to put a custom logo on for me. Luckily ident marking is like 5 min from my house

Another thing to consider. Put the lower together before you file (assuming that you don't have it in pistol format already). It would be a bad day in the shop if you break off an ear when installing the trigger guard.


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[Colten519]

Can you elaborate on that. I don't think I understood lol

[dallasb]

Originally Posted by Colten519

Can you elaborate on that. I don't think I understood lol

I'm assuming you don't already have a lower put together.

My suggestion is to build the lower before you send off for the stamp. From what I understand you can have the lower before having a stamp, just can't have a "spare" pistol upper and an AR in the same house. When you install the trigger guard, if not done correctly it can break one of the ears that hold the guard on. It's not the end of the world, but if I spend $200 on a tax stamp I don't want to damage the lower putting it together.


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[Colten519]

Oh ok I got what your saying I totally misread it. Very good point. Thanks!

[Theohazard]

Originally Posted by dallasb

[You] can't have a "spare" pistol upper and an AR in the same house.

Not necessarily. There's no federal law that says this, and according to both the Supreme Court's and the ATF's interpretation of relevant federal law, merely possessing the parts to make an illegal SBR isn't automatically enough to get you in trouble. You must have no "useful purpose" for having those parts, and at the same time those parts must also be in "close proximity" to each other.

The part about "useful purpose" is fairly clear; if you have a legitimate use for those parts, you can make the argument that you never intended to make an illegal SBR. For example, if you have a regular AR rifle, another AR pistol lower, and 100 short-barrel uppers, you could make the argument that those 100 short uppers were meant to go with the pistol lower, and you had no intention of illegally putting them on your rifle lower. But even if you didn't have a legitimate reason to have those short uppers (the AR pistol lower), the Supreme Court also says those illegal parts must be in "close proximity" to each other in order to be illegal.

I've never heard a good description of what "close proximity" actually means. I once asked an ATF Industry Ops guy what it meant specifically and he told me to ask a lawyer. I'd be willing to bet that just being in the same house isn't enough to automatically count as "close proximity". But I'm no lawyer, so that's just a guess.

(See the Supreme Court case United States v. Thompson-Center Arms Co., further clarified in ATF Ruling 2011-4.)

[Colten519]

Thanks for the tips guys keep em coming

[dallasb]

Originally Posted by Colten519

Thanks for the tips guys keep em coming

Only thing with the post above is he doesn't address constructive intent. My advice on that subject is to read the law for yourself and make sure you understand what they "mean" for it to say. I play it on the safe side as I don't want a 10yr vacation with bubba. Once you get a registered lower the general consensus is that makes it a little easier to argue the "I have an extra upper as I change calibers on this particular LEGAL lower".

Have you found a mag that will work with the bullets you are planning to use? I found that subsonics tend to bulge out the PMAGs where the GI mags works just fine. If you stay with a 20rnd instead of 30rnd it seems to make it easier to feed the rifle on any type of mag.


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[Colten519]

No I haven't looked at mags yet but that's a good point

[Colten519]

I know my brother in law uses pmags with subsonic and I haven't noticed a problem yet but that's not to say there isn't one. I agree with the not wanting a vacation with bubba. No thank you

[Theohazard]

Originally Posted by dallasb

Only thing with the post above is he doesn't address constructive intent.

My whole post is about constructive intent, specifically what the Supreme Court and the ATF say about it.

The Supreme Court case United States v. Thompson-Center Arms Co.(further clarified in ATF Ruling 2011-4) specifically describes the threshold for constructive intent, and that threshold involves you having no "useful purpose" for those parts, and it also requires that those parts be in "close proximity" to each other.

[dallasb]

Originally Posted by Theohazard

My whole post is about constructive intent, specifically what the Supreme Court and the ATF say about it.



The Supreme Court case United States v. Thompson-Center Arms Co.(further clarified in ATF Ruling 2011-4) specifically describes the threshold for constructive intent, and that threshold involves you having no "useful purpose" for those parts, and it also requires that those parts be in "close proximity" to each other.

You can do as you wish. My recommendation still stands. I would not keep a pistol upper and any unregistered AR in the same house. YMMV.

Having a pistol/SBR upper and an unused rifle lower would give someone a "useful purpose". At least that's how I read the ruling regardless of the "close proximity" wording. "Close" is a very subjective term.


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[Theohazard]

Originally Posted by dallasb

Having a pistol/SBR upper and an unused rifle lower would give someone a "useful purpose". At least that's how I read the ruling regardless of the "close proximity" wording.

That's not what the ruling says that that's not how legal experts interpret it. You're misunderstanding what it says.

You have it backwards: The "useful purpose" threshold is what helps you, it's not used to punish you. According to the Supreme Court and the ATF, if you have a "useful purpose" for having that short upper, you're OK. And you can have multiple short uppers that can be used on one pistol or SBR lower.

I have one registered SBR AR in my house, and I have several other regular AR rifles. I own an extra short upper for my SBR, and I keep all those parts in "close proximity" to each other. So I have a short upper and a regular AR rifle in "close proximity" to each other, but having the one SBR lower gives me a "useful purpose" for having that extra short upper. Yes, I own the parts to make an illegal SBR, but I also have a legitimate reason to have those parts. That's what "useful purpose" is.

[dallasb]

Originally Posted by Theohazard

That's not what the ruling says that that's not how legal experts interpret it. You're misunderstanding what it says.



You have it backwards: The "useful purpose" threshold is what helps you, it's not used to punish you. According to the Supreme Court and the ATF, if you have a "useful purpose" for having that short upper, you're OK. And you can have multiple short uppers that can be used on one pistol or SBR lower.



I have one registered SBR AR in my house, and I have several other regular AR rifles. I own an extra short upper for my SBR, and I keep all those parts in "close proximity" to each other. So I have a short upper and a regular AR rifle in "close proximity" to each other, but having the one SBR lower gives me a "useful purpose" for having that extra short upper. Yes, I own the parts to make an illegal SBR, but I also have a legitimate reason to have those parts. That's what "useful purpose" is.

Your arguing a point that includes already having a SBR. I'm guessing the OP doesn't have one otherwise be wouldn't be asking questions.

I have already said that once you have an SBR you can have multiple uppers.

We are saying the same thing, just not in the exact same wording. I agree, if you have an SBR and multiple uppers you are fine. If you have a pistol lower and multiple uppers you are fine. This is regardless of whether you own a nonSBR AR rifle.

The area of ONLY owning nonSBR rifles AND a pistol upper is what can potentially get you into trouble.


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[Theohazard]

Fair enough. But previously you said this;

Originally Posted by dallasb

[You] can't have a "spare" pistol upper and an AR in the same house.

Originally Posted by dallasb

I would not keep a pistol upper and any unregistered AR in the same house.

In those statements it seemed that you were claiming it's illegal to have a short upper and an AR lower in the same house, which is not necessarily true.

Originally Posted by dallasb

The area of ONLY owning nonSBR rifles AND a pistol upper is what can potentially get you into trouble.

Agreed. If you own the parts to make an illegal SBR and you don't have other parts that would give you a "useful purpose" for having them (a registered SBR lower or a pistol lower), then you could get in trouble if those parts are in "close proximity" to each other. But like both of us have indicated already, "close proximity" is a subjective term.

[9x19]

I have a stripped lower still sitting in the box.

When I decided to go SBR, I didn't want to worry over the above, so for $45 (cost of the lower) I could now buy and have a short upper in the house while waiting for that first stamp.

I did it because sales on uppers happen faster than the ATF processes form 1s.