Recon 100 rd drum

[MDG]

I purchased one of these drums and it jams every 20-30 rounds or so. I had the mag catch machined because there was some weld slag in it. The mag would drop out of the gun. It's behaving better but still jams. I have an M11 with a side cocker from usmachinegun.com. Anyone have a problem with this drum?

 

[shawnr1]

Yep. I have problems with my rounds dragging through the feed tower causing FTF. However, with the stock upper and a MacJack it functions 100%. The extra recoil solves the feeding issue.

 

[MDG]

My gun runs like a charm with the metal mags purchased from usmachinegun.com. I noticed the lips on top of the tower are trimmed back a bit more than on the drum. I'm going to get some grinding done on each side to match my current ones.

 

[medphys]

Trimming back the feed lips does two things. First, it allows the rounds to have a more aggressive angle for feeding and second, it allows them to release a little sooner so the rims slide up in place sooner.

This may not be your issue though... once you cut them back, you can't make them longer without a welder and a lot of patience.

Could you post pics of the feed lips when it is fully loaded?

Are the rounds hitting the feed ramp?
Drum/tower clean?
Graphite lube on everything?
What ammo are you using?
What upper are you using?
Is the drum tower sitting at the same height as your other mags?

 

[MDG]

I'm a relative newbie but here goes.

Are the rounds hitting the feed ramp? Not sure of the question.
Drum/tower clean? Yes
Graphite lube on everything? Yes
What ammo are you using? Winchester White Box 155 gr
What upper are you using? side cocker from usmachinegun.com
Is the drum tower sitting at the same height as your other mags? Yes

I'm having problems posting pictures. They are too big. Any help would be appreciated.

 

[MDG]

Sorry 115 gr ammo.

 

[medphys]

Are you getting jams when you try to do mag dumps, short bursts, or both?

 

[MDG]

Both. If I could upload the pics, I believe it would become clear that my problem is with the lips on top of the tower.

 

[medphys]

If you cut them back, go slow.

 

[strobro32]

I used the zytel magazine lips as a guide for shape and length when trimming my PAMII magazines feed lips.

 

[BuffDragon]

jerry presser told me to use pliers/crescent wrench and gently/uniformly bend the feedlips out on a mag I was having issues with.
he pretty much said that people baby them too much.
fwiw, anyways

 

[strobro32]

I've heard Jerry say the same but what medphys and I are talking about is the length of the feed lips. If you trim them back on the PAMII mags to the OEM zytel mag feed lip length, the bullet can clear the lips and pivot into the chamber quicker.

There is a great demo and pictures of the before and after here.

Maybe we'll get lucky and one of these mfg'ers will have purpose build mags soon. There are rumors floating around.

 

[MDG]

Thanks for the detailed info. I took the Recon drum to my C3 dealer today along with one of my metal mags that work well. He's going to grind the feed lips to match the "good" mag. That will hopefully solve my jam problem.