Compatible Magazines?

[dfosland]

When I put my build together, I bought 2x 10 Round MDT AICS pattern magazines in 6ARC/6.5 Grendal, they work, but the issue is that I am using the American Rifle Company Coup De Grace action which is AW cut, so I had to trim a bit of the mag catch on the back of the magazines in order to get them to seat in the chassis.  They feed fine, however, I am also working towards the AW pattern mags, and knowing that was a less common item, didn't expect to see any in 6 ARC specifically, so settled on 308, partially because 300 Win Mag, 338 Lapua, and 50 BMG are the only other ones out there right now, all 'a little too big'.

I was able to get lucky on ammoseek and Optics Planet had some 308 available, and have received a pair of them yesterday.  They seat well into the build, and as you are likely expecting at this point, the rounds don't exactly like the extra room in the mags.  I can seat them forward in the mag, but I don't think there is much/enough tension holding them in against the lips, and am curious if any one has ideas other than just being gentle with it.

One of the big advantages with these is they are double stack, so I wouldn't have to be killing fingertips when loading rounds into them.

Mostly looking for cross compatibility thoughts, and workarounds people have used.