BCM Pistol Lower and Gen 3 Pmags

[SteveL]

I have lowers from four different brands (BCM, PSA, Sionics, and Spikes) and all will take and drop gen M2 and M3 Pmags just fine. When I bought my BCM there was a lot of drama at the time about whether their lowers would readily take gen M3 mags. With the others I just got lucky I guess. When I bought that lower I was working at a shop that carried BCM so I made sure to get one that dropped them freely. I recall when this issue first came to light BCM took the stance that their lowers are designed specifically to take mil-spec mags and that anything else is basically a crap shoot. However, that was before the gen M3 Pmag became the de facto military magazine. I guess BCM hasn't changed their position.

[themonk]

The magic number appears to be .90 - anything that wide or wider I have found not to have any issues.

[alx01]

That's the thing, it sounds like if it can happen with BCM, LMT, and KAC lowers, it can happen with anyone's. I've been reading on here about people with Colt LE6920s that won't take the Gen 3s either, and it doesn't get any more mil spec than that.

First time I hear about 6920's having issues with PMAGS. Maybe was a bad run or something.

[alx01]

I have had lowers that have had drop free issues, I dont own them anymore. I am of the opinion that any lower I own must work with all magazines that I own, meaning pmags, usgi, tango down, emags, Daniel Defence, and lancers. I would consider all those quality magazines. If a lower does not work with them I dont continue to own the lower.

It's an interesting and very stringent criteria. I totally understand and agree with that approach not just in magazine well tolerances.
I've never experienced this issue, but I don't think that a drop free Magpul Gen 3 would be a hard requirement if lower is otherwise quality and in spec. Difficult to seat or noticeable binding to extract the mag - definitely an issue.

[MSplumber]

I think I'm just going to have to order it from Buds and have it shipped to my FFL. If I remember correctly, Buds will accept returns on new guns as long as it hasn't been transferred yet, so I'll just inspect it by bringing a few of my own Gen 3 Pmags and making sure it inserts and drops free before starting the paperwork.

[Stickman]

Personally, there is a large difference between the magazine not leaping free with the press of a button, and the magazine being hard to wrangle out.

I have more BCM lowers and complete weapons that I can think of off the top of my head, and no magazine issues with any.

[goaltendah1]

I own many BCM lowers/rifles and have zero issues with magazines.

My newest Colt 6920 that I bought last year (CR Serial number prefix) will NOT drop a Gen 3 mag free. I've bought BCM lowers for the last few years and have had zero problems.

Jeff

[JediGuy]

I got into the old threads about this just over a year ago, I believe. Brought a M3 magazine and tested the magazine drop at the FFL. No problems, everyone was happy. It was s fairly recent manufacture, as I emailed BCM out of curiosity. I’d guess you’ll be fine. Worst case, you’d pay to ship it back.

[36trap]

My next AR is going to be an 11.5", and I'm leaning towards BCM. I keep reading about how some BCM lowers won't accept Gen 3 Pmags, which happens to be the most numerous kind of my magazines. Is this a deal breaker for any of you?

Not a deal breaker for me. Can't expect a gun maker to chase every mag or mag revision under the sun to make sure it falls all slick like when you smash the button.

[themonk]

Not a deal breaker for me. Can't expect a gun maker to chase every mag or mag revision under the sun to make sure it falls all slick like when you smash the button.

Just to be clear the problem with BCM lowers was not their ability to have mags drop free it was that the over insertion tab on the Gen 3 PMAGs was not allowing the mag to seat all the way.