View Full Version : PMAG's not dropping free.
I purchased 15 PMAG's a year ago and 10 have been sitting in a sealed can and the other 5 were sitting out. They were all loaded to 28rds with the dust cover put on. I just got an LMT lower and was testing the mags and the 5 that were sitting out have a hard time inserting and removing. What would cause this? I don't have a caliper to measure the width or test fired for function (waiting on a BCG).
I purchased 15 PMAG's a year ago and 10 have been sitting in a sealed can and the other 5 were sitting out. They were all loaded to 28rds with the dust cover put on. I just got an LMT lower and was testing the mags and the 5 that were sitting out have a hard time inserting and removing. What would cause this? I don't have a caliper to measure the width or test fired for function (waiting on a BCG).
As far as I can tell, LMT magwells are on the tight side of spec. I've heard a lot of people say the newer LMT lowers won't drop pmags. I recently talked with Gene at LMT to RMA a lower and the subject of pmags came up. He stated that he had a pmag sitting on his desk to do some testing on because of the number of issues they're having. As long as the lower drops USGIs, I'm not sure much can be done about it. There is a small spot you can file down on the mags that usually will make them drop. Also, once you put a BCG in there, the added pressure on the bolt catch might be just enough to drop the mags.
Gutshot John
04-24-09, 20:58
I've never had a problem using PMAGs with my LMT lower.
What date do they have on them?
If you have a PMAG™ with 7/07 or 8/07 mfg date, there is a tuning procedure you can perform that may help improve drop free performance. On these magazines, additional material is present on the front face of the Feed Tower Front Wall (see below). This added material can interfere with tighter magazine wells (front-to-back) causing some drag. Be aware that Magpul cannot guarantee the results of any modification and anyone performing said modifications do so at their own risk.
The tuning procedure may be worthwhile even if they're outside those dates.
PMAG™ DROP-FREE TUNING PROCEDURE
STEP 1 - BREAK IN
Break in magazine by inserting it into the magazine well numerous times (20-30 or more). Do not continue further once magazine starts to drop free. If the magazine does not begin to drop free readily, look for wear spots to determine any areas of interference. If the front or back of the magazine Feed Tower shows wear then proceed to STEP 2. If wear is present on the small Front Transition Angle between the base of the Feed Tower Front Wall and the Top Rib proceed to STEP 3.
STEP 2 - FLATTEN FRONT FEED TOWER WALL
Using a flat file, lightly remove material from the front face of the Feed Tower Front Wall. Concentrate on high spots underneath Feed Relief Cut and around and underneath the Feed Tower Molding Gate. Be careful not to remove too much material! The maximum amount that should be removed is enough to make the front face flat (planar). Test magazine often for drop-free ejection. Do not continue further once magazine starts to drop free.
STEP 3 - ADJUST FRONT TRANSITION ANGLE
Using a round file, lightly remove material from the small Front Transition Angle between the base of the Feed Tower Front Wall and the Top Rib. This area is located approximately 1/3 of the way down on the FRONT of the magazine. Concentrate on removing material in the downward direction (as the magazine normally sits in the weapon). WARNING: DO NOT dip underneath the surface of the Feed Tower Front Wall as this can create a very thin area in the magazine and structurally weaken it. Test magazine often for drop-free ejection. If necessary, repeat STEP 1 – Break-in and look for interference/wear areas.
PMAG™ MAGAZINE BODY FEATURES
Feed Tower – The top portion of the magazine that enters into the AR-15/M16 magazine well. It consists of approximately the top third of the magazine. The exterior walls of this section are generally flat and straight in order to slide easily into the rifle.
Feed Tower Front Wall – This flat, vertical wall is located on the front of the magazine and is the front section of the Feed Tower. It is rounded on the sides where there are two Locking Tabs toward the top and two Guide Tabs toward the bottom.
Feed Relief Cut – This shallow “U” shaped cut is located at the top of the Feed Tower Front Wall. It is in front of and below the bullet tips when the magazine is loaded. It allows clearance for the rounds to feed into the rifle Feed Ramps.
Feed Tower Molding Gate – This generally rectangular patch is located between the Guide Tabs. This area has some built-up material on 7/07 and 8/07 magazines.
Front Transition Angle – This feature is located approximately a third of the way down on the front of the magazine. It joins the base of the Feed Tower Front Wall with the front of the Top Rib. When viewed from the side it points approximately 60 degrees down and a 1/8” long.
Guide Tabs – Located below the Locking Tabs on the Feed Tower Front Wall. The Guide Tabs help stabilize the magazine in the rifle and help seal off the magazine well from debris intrusion.
Locking Tabs – Located on the top-sides of the Feed Tower Front Wall, these tabs engage the front of the Impact Cover (i.e. Impact Cover Locking Yoke).
Magazine Catch Groove – Located on the left side of the feed tower (i.e. Feed Tower Left Wall), the Magazine Catch Groove locks into the rifle Magazine Catch. This is a critical interface and should NEVER be modified. The lower protrusion (i.e. Magazine Catch Stop) prevents over-insertion of the magazine into the rifle. The Manufacturing Date Stamp is located directly below this area.
Manufacturing Date Stamp – This circular dial indicates the date of manufacture. It is located directly below the Magazine Catch Groove and Stop. The center protrusion contains an arrow with two numbers that indicate the year of manufacture (i.e. "07" for 2007). The arrow should point to one of the 12 numbers indicating the month of manufacture (i.e. “12” for December).
Top Rib – This feature is directly below the Feed Tower and separates it from the rest of the magazine. It is angled up at approximately 10 degrees when the magazine is viewed from the side. When inserted into the rifle, the Top Rib is directly below the rifle Magazine Well and wraps around the circumference of the Magazine Body.
Thomas M-4
04-24-09, 21:19
My lmt lower is 1 year old. I have 4 p-mags 2 of them drop free the other 2 almost drop free I MEAN THEY ARE just 1 hair away from droping free. Not worried about it I figure some use and they will probable start droping free on there own.
I've had a few do just that in my LMT.
Thomas M-4
04-24-09, 21:23
Good info Jerm
I mean it's weird that the 5 that werent locked up are the ones having problems. It just started to get warm again (85 degree temps) and I havent turned on the air conditioner so I'm thinking that might be a cause. Ill try those methods tomorrow.
I should add that some of the mags are snug when inserting them also.
Both of my LMT lowers wont drop PMAGS.
I end up stripping them anyway by hand just to ensure that it drops so its not that big of a deal to me.
As the mags wear they will start to drop but its going to take a while before they will.
I've never had a problem using PMAGs with my LMT lower.
Same here.
I had to modify most of my pmags to fall freely out of my LMT (my 3 orange mags and 1 of my black mags dropped free, everything else stuck). I recently just received 4 more FDE mags and I inserted the first mag and it didn't drop so I just grabbed the dremel and removed the tabs from all of them. They're all good to go now.
I've heard about some Pmags and LMT lowers having issues.
Are people still loading their mags with 28 rounds? I keep 30 in mine. :)
I have 3 LMT lowers, 2 RRA lowers, a Doublestar, a LAR, a DPMS, and a Territorial Gunsmith lower, and I haven't had a problem with any Pmags, M version or not, until I got the Territorial lower. I can't even insert the M Pmags in the magwell, and the regular ones won't drop free, but they come out with a little tug. I guess I'm going to have to try those filing instructions.
The most resistance I have for my Pmags is with my two '08 manufacture 20-round mags. The top rear of the mag tower, left and ride side, seem to be catching within the mag well when the mag is dropped. This is less an issue when the mag is loaded, but I don't envision dropping many loaded mags. This is true of a mix of lowers (CD Defense, Spikes Tactical, Superior Arms).
-B
I never assume that an AR mag is going to drop free, thus I always act to strip them.
If I don't have to strip it, so much the better.
My LMT also has trouble with PMags. As a mater of fact, I've got 5 that I'm going to trade for LMTs. I'm just not that crazy about the PMags.
I have 3 Colts and 1 LMT. My first group of 5 black P-Mags would not drop free in any of the lowers. Mag-Pul replaced with no problems. Some of the replacements would not drop free. A little sanding cured that. I have since purchased several windowed pmags and they have all worked as advertised. I also have some non-windowed FDE mags that have worked. The black ones are the only ones I have had issues with. But Mag-Pul stands behind their product.
I have quite a few Pmags that I have been using for almost two years. The issue that I'm having is not with fresh Pmags, but with ones that have been well used. All of my fresh or lightly used ones will drop free from my LMT lowers. However, out of the 10 mags that I routinely use at the range, 7 of them won't drop free anymore. They all dropped free when new. I wonder if the mag body has swelled with use. I don't keep them loaded, I just load and shoot them during training.
I had a dozen P-Mags that would not drop free in LMT or Sun Devil lowers, however they all dropped free in two RRA lowers. 15 minutes with some sandpaper per Magpul's instructions and they all drop free in all lowers now.
Sand here
http://i134.photobucket.com/albums/q111/rob_s/website/Painting%20Pmags/PMAGNUBS.jpg
Thomas M-4
04-27-09, 12:30
rob s I tried you tip it works great thank you.
I just completed building an Anderson Manufacturing Lower Receiver. My Gen M2 MOE PMAG 30 would not drop freely. I did a WEB search and found many articles about this issue. I tried sanding the magazine spline and other areas that were shown on different sites. I have been a big fan of Magpul products for years and use some if not all their components for most of my AR builds. I Inspected the Mag well closely and found the Pmag MOE Trigger Guard was extending ever so slightly into the well. I used my Dremel to remove a bit of the forward trigger guard material and now Life is Good! I’m not sure if this will help a lot of people but my mag would drop about a half inch and I had to pull it out. If you have a MagPul MOE trigger guard give it a try.
Wolfpack45
04-14-14, 13:53
I have had 2 LMT lowers out of 10 have this issue with the PMAGs. One with just PMAGs, the other had the issue will everything but GI mags. A few minutes with a high grit sandpaper (800 grit or more) and it will be just enough to smooth it out enough to be perfect. And dont go all he-man on it, let the paper do the work, that way you dont take anodizing off, you just smooth it. If the only mags having issues are PMAGs, then I would just sand the mag, and not the lower.
You guys realize that this thread is over 5 years old, right?
Wolfpack45
04-14-14, 15:38
You guys realize that this thread is over 5 years old, right?
Not until just now, lol. That said, the lower I had an issue with I bought 3 months ago.
Talywhacker
04-15-14, 16:10
They taught me to never assume the mag will drop
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