August 17, 2008, 11:12 AM
I am in the process of filling out paperwork to SBR an LMT AR lower. I plan on using an LMT 10.5" upper. I know in the past you could put a range or < a certain length, but now they are more strict. If I measure my lower from stock (extended) to center of front pivot pin, I get 18 5/16" (mesured from top of stock, the furthest point). A guy online reported contacting LMT about the length of the 10.5" upper (from end of barrel to center of front pivot pin) and was told 10.655" (I contacted LMT for confirmation, but have not yet had a response). If I add my measurements, I get an overall length of 28.97." Would it be safe to simply state 29" or should I write something like "approximately 29." I guess my question is, how accurate does the measurement have to be? Thanks!