Magazines, whats the difference

[Stovestoker]

Can anyone break down the real difference in a Grendel mag V a milspec 5.56 mag?

[Old Bob]

As far as as I can tell, the biggest difference is the follower. The .223/5.55mm follower has a shallower rib than the Grendel follower. Another difference could be the first internal ribs in the mag body that guide the bullets into the mag. The space between the right & left ribs appears to be a bit wider in the Grendel mag than the .223 mag. The larger diameter bullets in the Grendel cartridges would surely necessitate this.

I measured some of my mags: An aluminum, 20 round G.I. 5.56mm mag was .570" between the ribs. A commercial, stainless steel 30 round .223 mag was .600" between the ribs. Two of my stainless steel Grendel mags were .640" (10 rounder) & .644" (25 rounder).

[Rosecrans1]

Hi SS,

In a nutshell, the follower is just one difference. I tried changing out just the follower. WRONG! Spring tension, follower, width, receiver fit, etc.

[lazyengineer]

Bigger diameter round. As it turns out, that's OK, because the ribs inside a 5.56 mag make a standard AR mag bigger in width than it really has to be - which I hadn't really considered before. So make the ribs a little more shallow, and now the mag is still big enough to allow the bigger diameter Grendel round to still fit and to stack smoothly. But with that, need a bigger follower, and need different angle magazine lips.

you CAN make Grendel work stuffing a few rounds into a standard 5.56 mag, but only a few, and don't bank on it.

[TomSawyerNW]

Bigger diameter round. As it turns out, that's OK, because the ribs inside a 5.56 mag make a standard AR mag bigger in width than it really has to be - which I hadn't really considered before. So make the ribs a little more shallow, and now the mag is still big enough to allow the bigger diameter Grendel round to still fit and to stack smoothly. But with that, need a bigger follower, and need different angle magazine lips.

you CAN make Grendel work stuffing a few rounds into a standard 5.56 mag, but only a few, and don't bank on it.

Agree. I experienced feeding problems with a 5.56 mag in a Grendel. In a couple of my Grendels, this doesn't appear to be an issue, however. But I make a point to match 6.5 mag with Grendel.

[Dt219]