Name some.
My PSA and Doublestar, factory built lowers are not stalked. ( I'm 99% sure, I have to go to the safe to look.) Anyway go to a gun store and look at rifles, and see how many are stalked.
@ mtdawg169 I have had a few RRA factory built lowers and never ran across one w/ red locktite when I changed the back plate. I'm not sayin' they never did it, I just havent seen it... And I'd be waaay pissed if my RRA LAR-8 had red locktite on the castle nut. ( I'll have to check to see if its stalked, I know its at the front of the gun safe where I can get to it.) But yea, the M4 style rifles should be stalked from the factory.