I got me a nice used blued Model 11 in 22-250, 4.4" spacing top bolt release,blind mag.

I bookmarked this sticky years ago because it is great:
https://www.savageshooters.com/conte...Parts-Tutorial

The question is, what does (NBR) & (HFP) under the part #s ??

I want a Blued bottom metal #106704 but I'm afraid to order it because of the (NBR)

Also I am assuming that these are all 4.4" for the short actions.

Thanks in advance