This is the mag type in question that fits myAR10 hoping to fit an M1A I am eyeballing. Can you give it a check for me?
View attachment 673574
Thank you!
No, that wouldn't work in an M14/M1A. I've seen M14 mags modified for use in AR10s, but not vice/versa.
For a mag to work in a standard M14/M1A, it needs a hole just under the front lip for the rear end of the recoil spring guide to catch in, and a "stud" on the back for the mag catch to latch underneath to hold the thing in place.
M14 mags kinda have to be "rocked" into place front-to-back like AK mags. They aren't as easy to jam straight in as AR style mags.
From what I've experienced and read, Checkmate makes good M14/M1A mags, without you having to hunt down Vietnam-era M14 mags like we used to from 1994-2004. And I believe they are still OEM for Springfield Armory:
The Check-Mate Springfield M1A .308 20-Round Magazine is an affordable aftermarket centerfire rifle magazine, engineered to deliver a snug fit and factory-like performance at a price anyone can afford. Featuring a heavy-duty stainless steel body and a
gunmagwarehouse.com
Edited again to add: AR10 mags also have completely different followers, which wouldn't ever engage the bolt stop on an M14 or M1A on the last round.