I bought a Pmag Gen 3 10 round magazine for my Seekins SP10, 6.5 Creedmore. It is an SR25 style which I was told runs in these rifles. On the left side the notch, that appears to be the catch, and it’s is not identical. The 20 rounder has a slot cut into it and the 10 rounder does not. I attached a picture of them side by side. Will this 10 rounder function fine? I have not yet shot it and was wondering why they are not identical. Thanks.