I went to Basic Training at Ft. Knox in the winter of '78, it was cold (-8 at times, the Ohio River was frozen over), and while we were using LSA on our M-16s, I can't recall anyone having to re-qualify due to rifle problems (some just couldn't shoot worth a damn, but at least the old rifles worked, mine was an H&R, yes, H&R made some M-16s).
I never experienced any colder weather than that while I was in the Army. LSA is basically the same thing as Lubriplate, a lithium grease.
