[texcl2]

So every mag Ive tried works great but colt gi mags. They will lock in chamber the 1st round, It will fire the first round and the magazine will fall out. I have older colt mags and just got some brand new ones made late last year. They all do the same thing 100% of the time.

 

[MarkB1]

Are the mags fully seated? Can you remove a seated full mag with a hard pull? It may be that the Colt mags are not allowing the mag catch to get fully engaged on the mag catch lip. I haven't tried to fire my Colt GI mags yet but they do seem to lock up good in the magwell. I have been using Magpul Gen 3 mags (20 & 30 rounds) successfully.

 

[Lefty2Guns]

Weird. Only actual Colts I have are my USGI 20 rounders, and they worked without issue (only ran 2 or 3 of them that I recall though). Also tried some some D&H and Blackhawk brand mags (former aluminum, latter steel I believe), no issues there either.

Have you tried separating the lower and observing as you insert the problem mags?

 

[newtothis]

I have 1(Colt) 20 rd; works fine. Magpul (4)30 rds & (1) 5rds work too. Try putting 1 less round in mags and test.

 

[texcl2]

20 rounders work fine, but not 30 rounders. They do lock in fine. Its wierd.

 

[zaitcev]

I was sure that the USGI 30-rounder was actually made by OKAY. The profit margins weren't fat enough for Colt.

 

[texcl2]

We were issued 30 round colt mags made last year they dont even work, the okay mags i have fit and work.

 

[BeoWolff]

My AR-15 gi metal mag didn't work with my RDB either, so I took a flat head screwdriver and bent the magazine catch on it a bit. It works great now, and it still works fine in my AR.

 

[HBeretta]

My usgi elander steel mags work just fine as well...

 

[gunnut123]

I have a MCI 100 rd drum , like a beta mag and seems to lock in good , only one I have tried so far but just got my gun home and have not been to the range yet