GI pins are longer, and LARGER IN DIAMETER.
THIS LEAVES YOU WITH SEVERAL DIFFERENT OPTIONS:
1.] You can turn down the GI SPEC pin [ which SHOULD BE hard as he11]
OR,
2.] you can drill out the receiver for the larger pin
[A PROPERLY HARDENED M14 RECEIVER SHOULD ALSO BE HARD AS he11 ]
OR,
3.] you can glue a POPsicle stick inside your $ 850 sage STOCK.
OR,
you can do what I usually do ....
4.] find a piece of good quality 5MM steel rod to make a new longer pin. By a strange coincidence, 5MM just happens to be the correct diameter of the quick release axle on my mountain bike ... and I've got a several spare bike axles.
TTFN
LAZ 1