Here's something interesting: I have about 14 USGI mags I got when I left the Corps (I don't know how they ended up in my bags, but heck, they really wouldn't want me to send them back now, would they?), and I've found that around five of them are VERY TIGHT in my two AR's and in my DR-200.  They're not bent, dented, or otherwise damaged; just very tight.

Is there anything I can do to rectify this?  Should I sell them and get others?  What can be done?

Thanks!

I think Troy has a trick where he uses a vice or maybe its vise grips...I'm not sure which but many have said it works well, I guess you can IM him or maybe he will chime in.

Good luck!
Let us know how it works out too.

I have a similar problem with a few of my mags.

My first AR was a new Bushmaster.  In addition to the 10-round Bushy mag, I own 24 USGI 30-rounders and 17 USGI 20-rounders.  Out of these, 14 of the 30-rounders were NIW (different manufacturers, but mostly Sanchez) and 10 of the 20-rounders were NIW.  

All mags function flawlessly.  All of the NIW mags slide in easily and drop free.  A few used 30-round and 20-round mags can be inserted and work okay, but they don’t drop free.

Here’s where it gets weird.  I recently built an Eagle Arms lower.  Some of the mags that are tight and won’t drop free from the Bushy are NOT tight and DO drop free in the EA.  BUT, some of the mags that aren’t tight and do drop free from the Bushy can not even be INSERTED into the EA’s magwell.

I can’t figure it out.  I’m not sure I want to put a mag in a vise either.

The whole thing is weird to me.

I've had a couple GI mags from desert storm that wouldn't drop free from a BM. I simply took out the spring and follower and squeezed the upper half of the mag body with my hands. I did it ever so gently at a little bit at a time until the mag would drop free. Went to the range and test fire them. They worked just fine.

Sometimes there are puckers between the spot welds on the front and rear overlaps.  

Remove the upper half from your lower and insert the mag.  With a thin feeler gauge, slip this around from the top and observe where the mag is binding.  You will not be able to do this at the front and rear, but can on the sides.  If the bind is on the sides, squeeze in a vise as per the responses above.

If you hold up to the light, and see that it is binding at the front or rear seam overlap, remove the mag.  A few strokes with a file should get it to slip in and out easily.  Then just touch up the finish with dry moly lube spray.

I did this on about a dozen tight mags, and now they drop free easily.

Great advice from all of you: I've gotten nearly all of them (with the exception of two) to drop freely!

Thanks, gents!