CZ 527 (Grendel) - Modification of Magazine?

[Oso]

My challenge is loading ammunition into the CZ 527 magazine designed for 7.62x39mm, which also gets used for 6.5 Grendel. I have a set of new factory magazines that are a difficult to load. When loaded with 6.5 Grendel the feed lips extend beyond the case body / shoulder junction. Loading the first round is easy, but loading the remainder of rounds is difficult. It requires depressing both the base and nose of the cartridge in the magazine in order to create enough space to get the next cartridge to slide in. I have larger hands so I can barely get my finger tips in during this procedure.

Has anyone attempted to mill away some of the length of the feed lips to better facilitate loading the 6.5 Grendel or even 6ARC cartridges? Any thoughts or insight would be greatly appreciated.

 

[mac86951]

Ahh, interesting issue. I think most of us figure out a loading method that uses a thumb of one hand to depress the loaded cartridge while using the base of the new round to slide over the shoulder of the currently loaded round.

You might be onto something by moving those feed lips back to past the shoulder; but I think you'll still have a challenge with the round tipping around a bit; combined with a potentially new challenge of the round presented as too high when cycling the bolt.

Does your magazine follower allow the round to tip bullet down when loading?

Sorry, I'm not helpful here other than to suggest a few dummy rounds and practice, or if you have a spare 527 mag, make the mod and let us know. Check it's function with a round in the mag +1 in chamber and "extract" the round in the chamber.

-Mac

 

[Oso]

Loading the first cartridge is no problem. The "thumb" technique works for loading the second round. However, by round 3 the spring tension combine with my big thumb just can't push down the loaded rounds far enough to help load rounds 3-5 without it being a chore and shaving my finger nail. Honestly, this is the only issue that I've had with any CZ 527. I haven't encountered this issue with any other 527 magazine that I use (.223 or 300BO). I think this issue for the Grendel magazine is a holdover from the magazine being designed for 7.62x39mm case geometry (significant taper along body) as compared to the relatively straight sides of the Grendel case.

The CZ 527 magazine does a great job of holding on to the cartridge until the extractor groove reaches the end of the feed lips. I was playing with my calipers... If I remove 0.150"- 0.120" from the feed lips then it would expose perhaps enough of the case shoulder to allow the next round to push it downward. I used low-tech simulation of shortening the feed lip in the photo... I pushed the cartridges forward. The round at bottom is 6ARC (slightly short case length) and top is 6.5 Grendel (red tip).