Tight Mags in New Lower

[GI Sandv]

I just put together a new gun with a Del-Ton lower I found on sale. I bought the Magpul P-Mags and, when I got everything home, discovered that they do not drop free. They require a slight tug in order to get them out. Nothing unmanageable, but as I said, they do not drop free. I didn't get any aluminum mags this time so I can't compare to see whether those drop free. I should have brought the lower into the store with me (especially since it's 1.5 hours away) and checked this ahead of time but didn't think to do so.

My questions are: has anyone else had this problem? Have you found that it is usually the mag well, the p-mags, or some combination of both? What did you do, if anything, to fix it? I'm afraid to open the other p-mag bags to try those in there in case I decide to take them back. Thoughts?

[AK103K]

Both my Armalites dont like the PMags, the one to the point the mags wont go in at all. They also have had troubles with some commercial metal mags as well. They have always worked fine with GI mags though.

[Technosavant]

That's normal for Pmags.

Pmags are designed around the Colt magwell, which seems to be a little more generous than others. Magpul later redesigned the Pmag (to the Rev M spec) that helped with this drop free issue, but did not necessarily solve things. Their Emag seems to work in these rifles.

In my own experience, here's what I've found:
CMMG, Aero Precision lowers- Pmags work fine
Superior Arms lower- early Pmags won't drop free, Rev M will
Spike's Tactical lowers- no Pmags will drop free

IMO, you can hang onto those mags; they'll work fine, they just won't drop free. Or you can return or sell them and get some others... I tend to lean towards the TangoDown ARC or Brownell's GI mags with Magpul followers (since Pmags won't drop free in all my rifles, I've pretty well quit buying them). There's many other mags out there that are decent too.

[TacticalDefense1911]

Techno, add Stag lowers to the list that the P-mags work in.

OP, I'd try a GI mag before I got to excited about it to see if it drops free. If you have issues with the GI mag then your lower is probably out of spec.

[CLC]

I have a hard time inserting my one and only pmag into my stag lower but it drops free. All my GI mags work fine. After some good use I bet they will drop free.

[madcratebuilder]

AR's are made to except usgi mags, aftermarket mags can and do cause problems with some lowers.

[Metal god]

I have a Del-Ton and a PSA . Im in CA so I have the standard 10 round steel mags that come with the guns when you buy them . I also have some 20 and 30 round pmags I got at the gun show . The pmags have the blocks in them so they only except 10 rounds . With my Del-Ton all the mags I own drop free with no problems . The PSA has a problem with the 20 round pmags with inserting and extacting but not the 30s . What I found to be the problem was there are some rib like things on the back side of the mag where it slides into the magwell . All I did was took a razor knife and carefuly cut the ribs back so they were flush with the back of the mag . After that they worked great :D

[Basement-Gunsmith-Z]

Get the dremmel:D

[Metal god]

Or belt sander :confused: