I want a Sig-braced AR pistol in a dedicated upper .22LR with around a 10" barrel.

I have pre-ban stripped receivers that have never been built out yet - do I need to use one of those?  
Or can I buy a new stripped receiver and keep the pre-bans for another day?  

As a .22LR, a lot of the rules don't count or something, right?


What do I need to know, and are there any companies you'd recommend for a ~10" barrel and bolt?



Miscellanea:
It would be used with a Sparrow suppressor I have coming, primarily to let my kid (currently 4YO) get experience with a rifle that isn't huge and loud.  
Yes, I'm aware I can buy a Cricket for that purpose, that's not the point.  I have almost enough spare parts to build it, I'd just need the barrel, bolt, and arm brace/tube.
I'd also like it to be a pistol so that I can travel interstate with it without filling out the permission slip (I have SBRs already; that's not what I want this for).
This is to take to the grandparents' land out of state and let my son bust cans off the back porch.  We already use airsoft for that, but eventually he'll be ready for a real firearm.
Yes, he's properly supervised, we go over the rules, everyone wears eye protection, etc.

If it can't be done in MD, then I'll just tell the grandparents to buy a lower in their state and I'll build it and leave it there, just bring my can back and forth.

Thanks in advance.

You can buy a new receiver, and build it into a pistol. Save the pre-bans. It gets murky if your grandparents buy it in their state, and you bring it back to MD at any time... I wouldn't do it, seems risky.

Because it's an unmodified ar-15 receiver, the "rules" apply, but since you're building it into 22lr, it's not evil.


I'd get a CMMG barrel and bolt assembly, then use their BHO adapter to train him on the bolt release. They make 9" barrels, but if you're really set on a 10" barrel, I'd go with a standard length (or whatever is cheap) and have adco cut it down.

That's what I'm looking for, thanks.

So basically, I can just buy a new receiver, build it into a .22LR pistol, and it gets treated exactly the same under the law as my threaded barrel 22/45.

Which is what would make sense, but of course making sense is rarely what the law is about.


I saw the 9" barrel, and it'd be cheaper/easier to just go with that.  It'll recess the front of the can back beneath the handguard maybe a little bit, but I guess I won't know until I actually have my can and can build it out.

I guess there's no harm no matter which way it actually works out.