BCM Lower not compatible with PMAG Gen3

[Bolverk93]

In case anyone else wasn't aware of this. I wasn't.

Apparently not all BCM lowers are compatible with M3 PMAGs. I just completed a build using a BCM lower. When I took it to the Range I realized that I could not fully seat any of the Gen3 PMAGs I brought. The issue is that this version of the PMAG has a tab on the spine of the mag to prevent over insertion. On this lower that tab prevents the mag from being fully inserted.

I e-mailed BCM about it, and their response was that this sometimes happens with their lowers, and I should only use mil-spec mags with their "mil-spec" lowers. They claimed that there are no tight controls on this area of the lower.

The issue that I take with their answer is that M3 PMAGs are mil-spec in that they have been issued an NSN (1005-01-615-5169) and are approved by the Army and the Marine Corps. In fact the mags I was using were issued to me, and are what all my teammates use in our Colt M4s with no issue. I have also never had issue using these mags with my DD rifles or guns built on Spike's lowers.

Live and learn. I'll stick to Colt and Daniel Defense, or even Spikes lowers when I want to build something.

[mig1nc]

I have a Noveske with the same problem.

But I have a cheapo range toy poly lower that doesn't... Go figure.

I am surprised with the BCM response though.

The M3 PMAGs have problems with lots of different weapons. But they seem to be great for their intended role.

Sent from my Pixel 2 using Tapatalk

[Renegade]

The issue that I take with their answer is that M3 PMAGs are mil-spec in that they have been issued an NSN (1005-01-615-5169) and are approved by the Army and the Marine Corps.

Being MIL-SPEC and being issued are two different things.

PMAGS are not MILSPEC nor are they STANAG 4179 compliant.

[Bolverk93]

Perhaps I should not have claimed the PMAGS to be mil-spec. I'm not prepared to argue what constitutes mil-spec or not. Regardless they are approved by the USA and USMC, which indicates a certain level functional testing with mil-spec weapons.

The purpose of this thread was really to make people aware of an existing issue.

*Edited to be more cordial.

Looking at MagPul's description of their M3 mags it states "the GEN M3 is optimized for Colt-spec AR15/M4 platforms".

Colt-spec is apparently now a thing.

I will stick with Colt and Daniel Defense from now on.

I'm not going to sign up for photobucket.com just to post pictures, but there is a discernable difference between my DD lowers and this BCM.

The DD lowers are flush with the trigger guard at the magwell. The BCM magwell extends a fraction of an inch below the trigger guard.

There is no wearing in of these mags to fit. Also, I have already run thousands of rounds through these mags in my work gun.

[Grip]

I have a KAC lower that does not accept NHMTG mags, but works with every p-mag I own.

[17K]

I have a KAC lower that does not accept NHMTG mags, but works with every p-mag I own.

I'd let KAC know about that. NHMTG and Okay are the same mags and the same mags that KAC uses.

[jethroUSMC]

Also the M3 magazines state that they sometimes need to be worn in a bit to fit all lowers. It took more than a few times inserting and removing the mags probably several minutes per mag until they fit in all of my lowers.

[Omega9]

Beat Trash had the same problem a few years ago.

https://www.m4carbine.net/archive/in.../t-169913.html

[Beat Trash]

Beat Trash had the same problem a few years ago.

https://www.m4carbine.net/archive/in.../t-169913.html

I had this issue in 2015 when putting together a gun to be used as a personally owned/departmentally approved patrol rifle. The lower I bought was going to be paired with a BCM factory assembled upper. When I observed the issue with the MagPul M3 magazines not seating properly, I contacted BCM's customer service, hoping the issue would be resolved. To their credit, they had me ship the upper and lower back for inspection.

The upper and lower were returned with a note saying they were within spec for BCM. The note stated that portion of the forging that was an issue was not part of the original TDP, therefore, they did not consider it an issue, so long as one used Mil spec magazines. I called the CS department back and was given the same information about only using mil spec magazines in their lowers. Once that was said, the CS rep proceeded to convince me that I should purchase and use the Tango Down ARC magazines that his company sells (Not a Mil Spec Magazine...).

My agency had around 300 S&W M&P15's fielded at the time. And the agency was transitioning over to the MagPul M3 magazine (They have since purchased a substantial amount of additional rifles). These guns didn't have an issue with the MagPul M3 magazine, nor did any of the Colt 6920's in my safe. When I mentioned that during my conversation with the CS rep, he proceeded to share his opinion on why an agency should never issue the M3 magazine as it's a liability issue that could get people hurt or killed. I distinctly remember this conversation when I first read that the Marine Corps was adopting the MagPul M3 magazine as their go-to issued magazine. As a Former Marine, I tend to believe the the Marine Corps knows a thing or two about small arms. Apparently they do not think the MagPul M3 magazine is a liability issue.

I realize that now, as well as in 2015 when I started the linked topic that there are a lot of BCM supporters on this site. I actually caught a lot of hate for starting the original topic. My intent then was not to bash a company, but to let other consumers know of a potential issue. Especially any fellow LEO's who planned on using this product as a Patrol Rifle. BCM can make some outstanding products. In 2015, I owned two of their factory uppers built around their ELW barrels and using their gunfighter comp. The paring of the two made for an excellent upper. But my personal experience in dealing with their company, especially the followup phone conversation I had with their CS, left a very bad taste. so much so that I should off every BCM product I owned.

If you own a BCM lower that will seat a MagPul M3 magazine, or if you own a BCM lower and never intend on using a MagPul M3 magazine, more power to you. I'm sure it will give you good service. But after my personal experience when dealing with their company, I will not purchase another one of their products. When officers approach me for recommendations or advice, I can not in good faith recommend BCM after my experience. Especially when working for an Agency that issues the MagPul M3 magazines.

[officerX]

I have 2 BCM lowers and I use M3 PMAGs exclusively and have had 0 issues.