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+--- Thread: Would an AK drum feed 6.5 Grendel? (/showthread.php?tid=23334)
Would an AK drum feed 6.5 Grendel? - depletedyourcranium - 05-17-2021
Specifically talking about the old style back-loading clockwork drums? I don't have access to one to play around with, but I was thinking it would be a neat project to try and make work, either in an AK/VEPR in 6.5 or perhaps adapted to the STANAG top end like some of those 7.62 Chinese drums. Seems like it might work sense there isn't much stacking to the rounds so you have less of an issue with the decrease in taper going from 7.62 to 6.5.
Would an AK drum feed 6.5 Grendel? - TexasSlinger - 05-17-2021
in theory it could. Drums aren't the most reliable. Contact Evocatus Strategic
Jeremys a cool dude!
AK Guy has done a build as well in 6.5 grendel
https://evocatusstrategicllc.com/
Would an AK drum feed 6.5 Grendel? - A5BLASTER - 05-17-2021
depletedyourcranium Wrote:Specifically talking about the old style back-loading clockwork drums? I don't have access to one to play around with, but I was thinking it would be a neat project to try and make work, either in an AK/VEPR in 6.5 or perhaps adapted to the STANAG top end like some of those 7.62 Chinese drums. Seems like it might work sense there isn't much stacking to the rounds so you have less of an issue with the decrease in taper going from 7.62 to 6.5.
It would not work. The case taper is too diffrent to stack that many rounds and reliably feed. Normal mag capacity possibly a high cap drum isn't going to work.
Would an AK drum feed 6.5 Grendel? - depletedyourcranium - 05-17-2021
A5BLASTER Wrote:It would not work. The case taper is too diffrent to stack that many rounds and reliably feed. Normal mag capacity possibly a high cap drum isn't going to work.
I'm not sure if you know how those AK drums feed. The rounds aren't all in contact; they're separated by sections of a gear. The only times the loaded rounds are in direct pressure, stacked, is at the top where they feed, and it's only 6-8 rounds at a time.
Watch this vid, he does a demonstration of the mechanism in the first 2 minutes. If you've never loaded one it gives you a good idea of how the thing works:
https://www.youtube.com/watch?v=9L0vjEDDFI0
Would an AK drum feed 6.5 Grendel? - LRRPF52 - 05-17-2021
It might work with 90gr TNT and similar COL cartridges, but it wont work with anything longer than that.
I just tried to load a 123gr ELD-M factory round into an AK 30rd mag, and the COL is too long.
90gr TNT loads in fine.
Notice the 7.62x39 COL:
![[Image: ?u=https%3A%2F%2Floaddata.com%2Fimages%2...f=1&nofb=1]](https://external-content.duckduckgo.com/iu/?u=https%3A%2F%2Floaddata.com%2Fimages%2Fdatabase%2F7.62x39mm6.gif&f=1&nofb=1)
Would an AK drum feed 6.5 Grendel? - A5BLASTER - 05-17-2021
depletedyourcranium Wrote:I'm not sure if you know how those AK drums feed. The rounds aren't all in contact; they're separated by sections of a gear. The only times the loaded rounds are in direct pressure, stacked, is at the top where they feed, and it's only 6-8 rounds at a time.
Watch this vid, he does a demonstration of the mechanism in the first 2 minutes. If you've never loaded one it gives you a good idea of how the thing works:
https://www.youtube.com/watch?v=9L0vjEDDFI0
No I sure didnt know that, thank you for the info.
However I still think it would not work due to case taper differences. The internal gear would still need to hold each round by the case in the gear teeth. So the diffrence in case taper would throw off how the case will sit in it.
Would an AK drum feed 6.5 Grendel? - tpk - 08-16-2021
It works just fine with steel cased Wolf but you need a bullet guide.
Would an AK drum feed 6.5 Grendel? - depletedyourcranium - 01-05-2022
Okay so an update on this experiment. I was able to acquire one of these AR15 7.62 AK style drum mags. I didn't try any brass cased ammo but I did load it with some steel cased Wolf. Bottom line is that it will not feed with the back cover closed. The cartridge OAL is too long and the friction between the case head and the back cover prevents proper cycling. However, with the back cover not fully latched... it does seem to feed just fine, at least with hand cycling rounds. So now the mouse wheel in my head is spinning up solutions to just increase the gap between the back cover and the drum body securely and reliably... and I think if I do that, it may just work great. LRRPF52 hit it on the head suggesting the COL was going to be the issue. I tried shimming the inside edge of the drum body where it meets the back cover with some folded aluminum foil, probably in the range of 0.02 in which is obviously not going to be enough. I'm not much on metal fabrication, so I think my first attempt will be to draw up and 3D print a new back cover. I'll follow up with any future developments, good or bad.
Would an AK drum feed 6.5 Grendel? - LRRPF52 - 01-06-2022
3D print a new drum that takes into account 6.5 Grendel COL and case taper for the magazine well body.
Materials strength for additive mfg is now at the point where structural things can be done that couldnt with SLA.
Advancements in 3D printing are happening faster than many of the geeks can even keep up with.