Building a 6.5 grendel on Savage action

[graybear]

Hey shooters. I've run into an issue and I wonder if anyone has some insights on it.
I'm building a 6.5 grendel on a savage 11 action (detachable mags) I have... almost finished but when I load the DBM mags, the first round seems to feed but the others nose-dive something fierce!
I'm using 7.62x39 mags b/c that's the closest model 11 mag to a grendel round, as far as I can determine.

Do I need a different mag or is there a "fix" for these to prevent the nose-dives?
Any info or solutions, thanks!

[savagecornmuffin]

Not sure sure what your mag setup looks like, but in ARs, a 6.5G will feed from a 6.8 SPC mag or a 6.5G mag. 7.62x39 is a tapered case. The Grendel is blown out straight. That's the cause of your feed issues. What x39 mags are you using?

[graybear]

It's the factory savage mag 7.62x39, for the model 11 DBM style accustock/accutrigger models (bottom style bolt release).
They don't make either 6.5 G or 6.8spc for that action, and some folks fireform the 7.62's to use in the 6.5G... so it seemed the way to go.
The difference in taper may indeed be part of the problem, since the feed lips would be expecting the 7.62x39 brass form... have to ponder what to do.
Savage part no. 108663.

[squirrel_slayer]

I would try and tweek the feed lips some or maybe remove some material from the rear of the mag follower (cartridge side) as to push the nose of the round upward or a combo of the two.