Aero Precision M5 magazine catch issue.

[CLP]

Some of you may suspect the problem I've run into just by reading the title of this thread. Issues with magazine releases and 308 ARs are nothing new. Here's mine:

I have an Aero Precision M5 lower.
Initially I used a CMMG LPK minus the trigger since I'm using a Geissele.

The initial magazine release assembly left the magazine release button recessed, almost flush with the side of the receiver. There aren't many threads that catch, but it's not a big deal since it can't back out accidentally. However, the lack of threading isn't what bothered me. Rather, it was the magazines (MagPul and Brownells, both brand new) that caused me problems. When inserted straight in, they lock in place. But just slightly jiggling it- to the right- and the mag drops out. So I tried testing the magazine retention from the magazine release being fully screwed in to just hanging on by a thread- literally- by testing, unscrewing one rotation, and repeating until the assembly was no longer screwed together. I had the same problem each time.
So I bought the Aero Precision mag release button, thinking the additional length of mag release button might allow the magazine release to be better situated in the mag well to hold on to the mags. Same problem with the Aero Precision M5 Mag release button.
Same problem with the Seekins cnc machined mag release button.
So I thought maybe the nub on the mag release that protrudes into the mag well which is responsible for retaining the magazine in place was possibly out of spec. So I bought an Armalite mag release. I didn't break out the calipers but did align them side by side and they looked identical.
Same problem with all three buttons on this new mag release. It will retain magazines, but if I add any play to the right, the mag drops. I could take a screw driver or awl and pull out the side of the cutout in the magazine itself to allow more connection with the mag release, but the Magpul is polymer and can't be easily modified. Am I doing something wrong? This is my eighth AR build. One of them was a 308 but it was an Armalite and I didn't have this problem. Gonna also post this one at Ar15.com. Thanks

 

[ChefJeff1]

Did you push in the button with a punch and screw down the piece on the left side of the receiver so the screw is flush?

 

[CLP]

it's a 308 AR, it's not going to thread that far- not that it matters, i tried it threaded fully to just hanging on one thread and every rotation in between. It's possible an out of spec mag well- Aero wants it back to check it out

 

[Robert]

I'd talk to Aero. Sounds like your mag well may be out of spec. These things happen, it is just no fun when they happen to "me"...

 

[ChefJeff1]

disregard my reply, I read mag catch but thought bolt catch.....it was late, I work nights....

 

[CLP]

Aero suspects it may be out of spec. Will be sending it to them.

 

[saitek]

mag catch

hey clp post and let me know whatyou come up with for a solution my dad is having the same problem's with his new build !

 

[CLP]

Currently awaiting a response from them on whether they want me to mail in the magazine release components I used (CMMG button, Seekins button, Aero button, CMMG release, and Aramalite release) to see if by chance it was something wrong with the components I was using. Will keep you posted.

 

[saitek]

mag catch

thanks i keep looking in .

 

[saitek]

mag catch

hey there this is a little up date on our part ,we come upwith the fact that the magazine catch is about .031 short of protruding enough into the magazine well to catch and hold the mag .the catch needs to be longer .i don't know what they are using in a complete factory rifle ,but they will never hold a mag . we plan on building om up with silver solder to try . i wonder if they use a different mag catch than the ar15 aero has a different part number on the small parts kit buy they use a extended mag release button i wonder if that is the only difference between their ar15 and m5 308 kit .there is only 1 number between the two ,they are impossible to get a hold of buy phone or e-mail .

 

[CLP]

Sorry for dredging this up. I was a little disappointed with Aero's customer service. I was writing one email a month asking for a status update (they sent a postage sticker and had me return the lower). Not one email was replied to. After three months, I got in touch with CS by phone and they confirmed the mag well was out of spec and wouldn't hold mags. They shipped out a replacement the next day and it'll hopefully arrive early next week. Still satisfied with their product and ultimate resolution.

 

[Youngwk2000]

Aero magazine release fix

You need the EXTENDED magazine release button sold by aero for $5 to extend out correctly. Also, I had the same issues with magazines catching and wiggling out on my 308. After contacting aero and aero telling me there was no recall on my lower being out of spec, I decided to slightly bend in the cmmg magazine catch and it fixed the problem. A slight bend not noticeable and all my mags held tight. No problems at all anymore.

 

[mdThanatos]

I got in touch with CS by phone and they confirmed the mag well was out of spec and wouldn't hold mags

Op's last post in this thread from April shows there was a resolution.

 

[CLP]

I had the Seekins extended button. Irrelevant though. It was a bad batch- confirmed by Aero themselves. Mag well was out of spec and mags had a lot of slop when seated. They dropped with lateral play (in the direction away from the magazine catch 'nub'. Took them a month longer than my last post indicating there was a resolution however. I kept calling and emailing and CS kept telling me one would be sent out "next week". Next week turned into four more weeks. I assumed they needed to get a new batch made? Brownells was out of stock of them for the majority of this time as well. Unfortunately, I actually had to write letters to their local PD, county sheriff, and ATF office a requesting assistance. Resolution came soon after. They mailed me a proper M5 lower. The rollmark is on the right side of the mag well which is the only cosmetic difference and the mag well has a flare and disallows any play of the magazine in the mag well. Overall, the rifle is fantastic. Function tested it and ran ~60 rounds through it last week to ensure reliability. Nary a hiccup. I'll continue to buy Aero products- they're good quality- but if something needs to be returned it'll become Pete Brownell's headache- not mine. Though I'm sure he has plenty of leverage with them.

Final summary:
1. "Out of spec magazine well" (words per CS)
2. CS experience was wholly inadequate
3. Aero quality is excellent (despite this manufacturing boo boo)
4. Current mag release button if from a standard AR 15 LPK and functions perfectly fine. Brownells and PMAGs seat and function (though the Brownells mags need stronger springs imo).

 

[ColoradoMinuteMan]

I have had some issues with my M5 as well. I notice when I compare my M5 to an AR-15 the tab that engages the magazine doesn't stick out as far inside the magazine well due to the face that the wall of the magazine well is thicker than on an AR-15. It has nothing to do with the depth of the button since the magazine catch will bottom out on the receiver notch regardless of the length of the button. I've considered trying an AR-10 magazine catch and seeing if that tab is deeper than on the AR-15 magazine catch. Most of the time mine holds but occasionally I'll have an issue.

 

[CLP]

it really only needs to catch a couple of threads- it can back out, so that's really just aesthetic

the problem with the out of spec lower was that, even with the long mag release button it didn't matter if you screwed it in just one or two threads, or bottomed it out- or any number of threads in between- nothing would help keep the mags in

the standard AR15 mag button i'm using currently is shy about 3-5 threads, but it's purely a cosmetic defect

if i was worried, i'd order another seekins and not give it a second thought

 

[$harp$h00ter]

I have just purchased two M5 .308 setups from aero. My first build that I did with a customer. I bought lancer AR10 mags and all three of the 20 round mags will not stay latched in. The 10 round Lancer mags are better but not perfect. I am concerned the magwell is out of spec but don't want to deal with long term CS issues to resolve it. It is a limited run multi cam set and will be a problem. Paid for Lancer thinking they would be a better, beefier mag, hmmm?

Am I reading the thread correctly that PMags work with this issue. And also Brownells?

I want my customer to be confident that the mag will not fall out while Hogg hunting in Texas.

 

[Alabama2010]

This took forever to become resolved. I should've just returned the lower to Brownells and called it quits. However, I sent it to the factory. They verified that the lower was out of spec. I had to wait four months for the next batch of 308 lowers to be made. The replacement was perfect in every respect dimension-wise and the ones Brownells are currently selling are the redesigned lower. I'm sure if your purchases of the M5 lowers were recent then you likely bought good lowers. I've only used two mags on my builds- Magpul and Brownells- and they both work flawlessly.

 

[$harp$h00ter]

This took forever to become resolved. I should've just returned the lower to Brownells and called it quits. However, I sent it to the factory. They verified that the lower was out of spec. I had to wait four months for the next batch of 308 lowers to be made. The replacement was perfect in every respect dimension-wise and the ones Brownells are currently selling are the redesigned lower. I'm sure if your purchases of the M5 lowers were recent then you likely bought good lowers. I've only used two mags on my builds- Magpul and Brownells- and they both work flawlessly.

Thanks for the quick response. I put a phase 5 ver2 ar10 bad lever on it to so I think it will need to come off. I will try the second lower later today. I ordered all through my sales rep at AP. No problems other than some of the CS complaints here or slow turn times.

 

[$harp$h00ter]

Ok. Just ordered four more brands / versions of magazines to test with my 2 Aero Precision M5 limited run multi cam builders sets purchased two weeks ago.

Magpul
Hexmag
Midwest PX
Brownells
USGI Metal
Lancer (20 round fall out or latch but easily disengage the mag catch, 10 round catch most of the time but do not easily disengage the catch without pushing the release)

 

[langenc]

My problem w/ an Aero lower is a Stoner 5 round will not seat when inserted (try to insert) w/ 5 rounds in it. Four rounds will seat but not 5.

 

[$harp$h00ter]

Update...

Magpul PMAG Gen3 SR/LR 10 round, perfect latching and feeding of rounds
Magpul PMAG Gen3 SR/LR 20 round, perfect latching and feeding of rounds

 

[mday10]

I had the same issue with my Aero M5 build. I have had great success with Hexmag 20 round magazines. They never fall out, however the Magpul 25 round magazines do the same thing you mentioned. Any wiggling and the magazine falls out. I believe the Magpul mags are slightly thinner which is why the play is allowed. I am just guessing but the rectangular latch on the actual magazine looks like it is shaped slightly different on the Hexmags than the Magpul ones. So that might have some effect. I was bummed that i cant used the Magpul mags but the Hexmags are good magazines anyway.
Hope this helps.

 

[Fredfrederson]

I just put together an aero precision ar15 lower and had the same problem. The slot on the left side was wider at the top and more narrow at the bottom. This didn’t let the catch go all the way in. I opened up the bottom with a dremel and it works fine. So if you look inside the mag well with your finger holding the catch in you can see if there is a little space there. Also it should be pretty well flush on the outside. Either the slot wasn’t cut out deep enough or in my case it wasn’t cut square. Compared the measurements to a Colt on both the catch and the receiver and both were off. I put the receiver on it’s side and tapped the catch in with a hammer and popped it back out. You could see where there was too much material in the bottom of the slot. Anyways you might want to check the dimensions before you modify mags and parts. I also got mine from brownells like somebody else said but it’s not worth the trouble of sending it back so I took chance and fixed it.