The Gun Counter

Is the 7.62 NATO "LR" headstamped surplus, OFB of any higher quality (more consistent internal dimensions) than the non-LR LC brass? Or, instead, does the "LR" stamp merely indicate the brass left the Lake City factory in Missouri loaded with the Sierra 175-gr HPBT bullet, and the brass is really of the same production standards as any other LC 7.62 NATO mil brass?

From what I have seen the LC-LR brass is consistent with the older LC Match brass I've used. However I don't think it is actually match per se, just that it is loaded with the 175 SMK intended for LR use. Anybody got the mil spec sheet for small arms can answer positively?