Graybeard Outdoors - View Single Post - Need to mod an AR mag for 1.7" cartridge
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post #8 of (permalink) Old 05-29-2019, 05:55 AM
lloyd smale
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Join Date: Nov 2002
Location: Munising MI
Posts: 20,679

I thought the same thing when I looked at the first mag of blackout I loaded. Way to short and way to much space to jump. Learned it didn't cause an issue. Just for grins ive loaded mags fast where all the bullets aren't all the way back and didn't give it the "Helmet tap" and they still run a 100percent. Now that is where standard ar mags can give some trouble with the bo. There are little nubs in the magazine that the bullets kind of ride on. With 30 cal bullets in a 556 mag it kind of has them feeding cockeyed. Have rounds in different positions in the mag and it can make it worse. File the nubbys down so that 30 cal bullets feed out of the mag straight or get dedicated bo mags that with some companys even have a slightly different follower and the problems go away. Problem you may be seeing is at 1.7 your substantialy shorter then even a blackout and the bullet might not even be riding on those nubs. The dedicated bo mags have then relocated a little further back so they may be in the correct place but thinking on it there only long enough to hit 30 cal bullets and might not hit your 223 bullets anyway. Take a look at your mags as you load them. Are the bullets staying straight in the mag or do they have a tendency to go sideways slightly. I wonder if youd be better off with a 762x39 ar15 lower and ak mags? but then I doubt the mags would hold the skinnier rounds without a lot of work and the right follower. Guess you can allways go the easy route and rechamber that barrel to 556 sometimes a guy has to look at why nobody else has done this and think that maybe its just outside the design limitations of the platform.
Originally Posted by Moose Ears View Post
Mags are the Achilles Heal of AR15 wildcats. That shortened case is going to be a real challenge because of the dead space the round has to travel before going into the chamber. It gives it too much room to get out of place and cause jams. You will most likely need to extend the feed lips somehow. Maybe spot weld some flaps to the existing lips? A mini tig rig and a good welder will be needed.


Last edited by lloyd smale; 05-29-2019 at 06:01 AM.
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