Thinking about getting an SBR before the AR hysteria starts up again. What's the best way to do it, buy a whole rifle, just buy an upper or buy a pistol and then later get my tax stamp and put a full size butt stock on it?

Also if I just buy an upper, is it legal to have it in my possession before getting the tax stamp? Can I use the same lower for a full length upper as well as the SBR upper?

I already have a Daniel Defense M4V7 with a giessele SSA trigger and was thinking about just buying a DD MK18 upper. Also I'm set up to reload .223 and .308 is it worth maybe going 300 black out over the .223?

Legally

If you have a lower you can build into a pistol and use pistol upper

If you do not have a pistol lower be careful about having a sbr upper as its a grey area

I would form 4 a Lowe than buy and an upper

This is the process I went through, but there are many ways to do it as you mentioned.

I bought my lower first and sent off the paperwork, which took about a month. During that time I assembled my lower and got it engraved. You can't legally own the parts for an SBR (i.e. the upper with a barrel less than 16") until you have the stamp in your possession OR you have a pistol lower. Once I had the stamp I then purchased the parts for the upper I wanted and assembled that.

Get the lower engraved first. That way you can send it for engraving as a regular lower, not an NFA item. Also if something happens to it (lost, damaged, bad engraving, etc.), you can do it over rather than have to live with it and possibly $200 gone.

I'd get the .300 for the sole reason of shooting subs. If you're set up for .223 you just need the .300 dies and you'd be good-to-go.

you only have to engrave if you Form 1 (build the SBR) if you buy a gun marketed as SBR youre good to go with out engrving)

I went with a bull pup rather than an sbr. Got a Tavor SAR 16". Shoots .223 with a 16" barrel but is shorter than a 10" AR with out the need for a stamp. It's hard to like if you haven't shot one but it's turned into my favorite semi-auto. A little pricey, but no regrets. Maybe another option to think about.

IF it was me, Desert Tech MDR

I just checked these out the MDR-C looks sweet. The bull pup is an idea. But I could just pay for the stamp, engrave my existing lower, and buy an SBR upper and be all in for around $1,100-1,200.

Not sure yet. May buy a pistol and pay for the stamp so I could use it on a different lower. I'm gonna look into the bull pups a little more.