Magpul SR PMAG Too Tight In Knights SR-25 Magwell

[mack7.62]

One cannot make a blanket statement about mags or mag wells, tolerance stack can bite at any time. The only way to know what is drop free is to test that mag in that rifle. This can be a PIA when dealing with an armory of rifles and grouped mags. Not all PMAG's are the same, depending on mould and possible other factors some Lot numbers will drop free in a particular rifle and some Lot's will not. My exposure to KAC SR-25's is limited but I have seen some problems with some rifles and some PMAG's and even some metal KAC mags. In other words in a certain SR-25 some lots (lot number is on wrap) of NIW PMAG's whether 10, 20 or 25 will drop free and some lots will be a little tight and some will be very tight. In another rifle the very tight mags might drop free and one of the others might not, just depends on one or more of the dimensions of the mag well and/or the mag itself. Same is true of KAC metal mags, some 10 and 20 rounders will DF and some won't. This is true of both new and used mags but problems seem to be more prevalent with used.

[Pappabear]

My old LMT and my new LMT functioned perfectly with all Pmags. Your LMT should be GTG.

I sold my two knights mags that came with my original gun. STUPID ME STUPID ME STUPID ME. They went to a good man but not my smartest move.

PB

[Fire4Effect]

My dealer called today and my LMT LM8MWS arrived. Looking at the contents in the box I noticed that the out of state dealer sent a 20 round PMAG magazine instead of the required 10 round PMAG magazine. The dealer has a high capacity magazine permit so it was not a problem with them receiving the 20 round magazine. The dealer had a 10 round PMAG in stock and exchanged it for the 20 round.

I also took my Knights aluminum waffle and steel magazines along with the PMAG 10 LR/SR magazine that would not work properly in my SR-25’s to the dealer’s store. I tried all of them along with the PMAG 20 LR/SR in the LMT LM8MWS. I obtained the following results when I inserted the different magazines in the LMT LM8MWS magwell.

PMAG 10 LR/SR: Snug fit. Did not unlatch when the magazine release was depressed and the bolt was retracted.
Knights 1994 vintage steel magazine: Snug fit. Did not unlatch when the magazine release was depressed and the bolt was retracted.
Knights 1993 vintage waffle magazine: Did unlatch when the magazine release was depressed and the bolt was retracted.
PMAG 20 LR/SR: Did unlatch when the magazine release was depressed and the bolt was retracted

Looks like the PMAG 20 LR/SR (20 round) will work in the LMT LM8MWS but the PMAG 10 LR/SR (10 round) will not. I wonder if there is someone in CA that can receive PMAG 20 LR/SR (20 round) magazines and convert them to 10 rounds. Obviously there is a significant difference between the external dimensions for the 20 and 10 round PMAG’s.

[Slippers]

As others have mentioned, a little tolerance stacking and/or differences between batches of pmags. I have 10rd pmags that drop free from my MWS without any issues.

Sand down the offending mags a little and move on.

[Fire4Effect]

As others have mentioned, a little tolerance stacking and/or differences between batches of pmags. I have 10rd pmags that drop free from my MWS without any issues.

Sand down the offending mags a little and move on.

I sanded the area the Magpul technician recommended. Obviously the entire magazine body needs significant sanding and that is too ghetto for me. I am surprised your 10 round PMAG drops free. The 20 round PMAG supplied with the rifle functions fine, but it does not drop free. Unfortunately CA does not allow me to possess it.

I will be satisfied if I can get 20 round PMAGS that have been modified for 10 rounds that unlatch when the magazine release is depressed. They don’t have to drop free. Looks like MagBlock makes what I need. I am going to return all the 10 round PMAGS to the dealer.

https://www.magazineblocks.com/magen...ag-blocks.html

[Fire4Effect]

I had an opportunity to pick up a few 20 round .308 PMAGS from Thordsen Customs that have been permanently modified to 10 rounds. They exhibited excellent workmanship using a Magblock 10 round block and a blind pin. They are also nicely marked “10 ROUND CAPACITY. And the best news is they drop free when the magazine release is pushed on my Knights SR-25’s and new LM8MWSF.