Well, not to step on any toes, but the answer will depend on the manufacture date of that receiver...
H&R dates to the late 1800's, NEF to the late 1980's. NEF started chambering higher intensity calibers. During this time, the H&R name was synonymous with case colored receivers, hard wood stocks with shotguns, black powder rifles and 30-30's and 44 mags. While NEF was building blued receivers laminated stocks and chamberings like 30/06, 308, 223's etc.
Knowing H&R predates NEF, so if you had pre 1980's H&R then definitely YES there is a difference and that old rec is likely NOT suitable for hi intensity chamberings.
The FAQ's has a list of SN prefix initials with its manufacturer date. But this only dates to 1940, I have a couple that predate this, yours could too..
http://www.gboreloaded.com/forums/index.php/topic,26264.0.htmlCW