CMMG 22LR conversion for AR has mag drop issues

[greenpea76]

Anyone experience this with their 10rd mags?
I went to try this conversion out at an indoor range and put 350 rounds through it with frequent mag drop issues in my Noveske N4 magwell for the first 100 rounds. Lots of chambering and ejection issues. Before heading to the range, I initially shimmed up the mag as I was able to pull it out easily without pressing the mag release. Imagine getting stopped by an uninformed LEO! I did leave the red BB tool in at the range though. For some that don't know, dropping mags with release is ok as the rule doesn't apply to rimfire cartridges.

So while at the range, I had to re-shim with aluminum tape to bias the mag towards the catch release latch. Had to add 0.016" of material to one side of magazine. After that, no more issues and 100% reliability with CCI 40 grain ammo. I Contacted CCMG the following day and was told all their mags are made the same way for standard magwells. He asked if mine was out of spec. I really don't know as I haven't found measurements, but the CCMG rep. says they could not warranty it and if I wanted to send mine back for inspection, I could do so. I didn't bother with it. I just said the mag just looks like it has a retarded aluminum bandage on it. He did mention something about CAV Arms lowers being the only one with that issue. Tried the same mag in an LMT and JD lower and they seem to fit decently without the shimming tape and did not pull out.

I'm wondering if my mag latch is the problem or the magwell. Anyone else have any mag drop issues with their conversion kits?

[LB21]

It sounds like your mag release isn't screwed in all the way. I'm using an LCW lower and while the CMMG and Blackdog mags I have are loose, they don't fall out on their own. I am also using a regular mag release, No BB as its a rimfire and can thus have evil features.

The most problems caused by the mags being really loose was using them with Armscor ammo. If I didn't support the mag, I'd get FTF, FTE, brass getting caught between the gas key and charging handle and the most exciting of them all out of battery discharge. After trying different brands of ammo, I found the best results I get are from Federal and Fiochi M320(? hard to find sometimes). If I use those, no problems whatsoever.

[greenpea76]

Hmm.....Last time I checked, the mag release latch is bottomed out on the flat inside the lower receiver.

Haven't tried other brands of ammo yet, but I may add more aluminum tape just to try and minimize the amount of wiggle once the magazines are inserted. Seems to me its the mags that are a little too small or the protruding lip on the mag that interfaces with the mag release latch is too small.