The Magnum follower (not H&H) is used with what Winchester called the "short magnum cartridge" rifles (.264 Win Mag, .300 win Mag, .338 Win Mag, and .458 Win Mag - not to be confused with today's "WSM" and "WSSM" cartridges). This is an original Winchester part in excellent condition.
We use the NRA Modern Gun Condition Standards Grading System for grading part conditions. You can read about it HERE