I'm building a straight .284 Win out a .270 lightweight hunter.

Of course I have the "STD LONG" mag box and follower. I know I can just monkey with the feed lips and buy a Mag follower but I cannot purchase the standard Mag follower p#102981 as it's been on backorder everywhere for months even from Savage direct.

If I wanted to just buy a whole magazine (I believe it's the 300 Win standard I'd need) what's the part number?