okay, so I bought a LMT/DSA lower and will not be able to finish it before I deploy so I have some time.  I planned on getting my SBR paperwork all in order and sending it to the ATF shortly before I go downrange so that when I get back, my paperwork will be in and I can go about building my rifle.  Anyway, to make a short story long, I need to know what the over all length of an M4 w/ a 10.5" barrel and USGI flash suppressor is.  If anyone can help me out on that, I would appreciate it.

You will get a lot of different opinions on this, Id suggested one of two:
1. 31.5" OAL 11.5" barrel length......Some will suggest this to lessen the confusion for examiners.
2. >26" OAL  >16" barrel length.........Some will suggest this covers all bases.

I have two Reg'd SBR lowers, First one I used No.1 Second one I used No.2,... Both went through fine.   Keep your head down over there........................Udog

Mmake sure you go down to like under 6 inches on barrel length and a corresponding OAL. You may want to try a kitty kat 7.5 or something.

Thanks, I apprciate the info.  I will certainly try to return w/ no additional holes.

A lot of people just put "Less than 16 inches" for barrel, and "Less than 26 inches" for OAL.
I asked our local class 3 guru ATFE agent about this and she replied that so long as the barrel is less than 16 or the OAL is less than 26, they really don't care what the exact numbers are, so long as it will qualify as an SBR.  Quite of a few of those over at HKPRO have done SBRs that way when switching from a stocked SBR or a non-stocked SBR is a posibility, like I did with my SW-.45-PDW.   With the 6 inch barrel, stocked it is 23 inches, but with the end cap on it is only 13 inches.  She told me I can switch back and forth at will, no problem as either one in addition to the 6 inch barrel all make it an SBR.

I was considering building a M4 or M4orgery. I know that if I use less than a 16" bbl (ie 14.5"bbl) then I need some sort of BATF paperwork to make it legal. Someone please tell me exactly why I would be doing this (other than not going to the hoosgow), how much it would cost, what is involved, is it similiar to a class III or can license/permit, does the paperwork need to be carried on you when you take it out, is there a background check for this, etc.?hinking.gif

blueheeler66,

You would want to check out the SBR FAQ in the Full Auto forum. To answer your quick questions, it's a $200 tax, you have to fill out a Form 4, get fingerprinted and proper photos taken, get the CLEO or equivalent to sign off, mail to the BATF, wait for approval, and then you build.

See Here

And here

Advice from some REALLY fine folks.

Danny

Thanks fellows.  Sounds like too much sugar for a nickel.hinking.gif   Looks like I'll be going for a permanent suppressor or the full 16" bbl.h.gif  Thanks again.