Ar-15 Magazine Question

American Red Neck · June 15, 2013, 06:41 PM

Hey guys so i have many aluminum ar mags. i recently read something on feed lips spreading and them being no good after that happens. my question is how long can i store these mags fully loaded before the feed lips spread to a point where the mags are no good anymore.

sailskidrive · June 15, 2013, 06:45 PM

I haven't had an issue with the mag lips feeding as much as the floor plates starting to bulge on USGI mags.

If you're going to store for an extended amount of time, buy some stainless steel or PMAGs.

Dfariswheel · June 15, 2013, 06:51 PM

I left an aluminum USGI surplus magazine loaded for between 20 and 25 years. The lips did not spread, (I measured them in comparison to a new, unused magazine) and when I shot the magazine earlier this year, it fired all 30 rounds perfectly.

I think the spreading lips thing is something left over from the days of cheap, non-spec magazines and early plastic mags.

sailskidrive · June 15, 2013, 06:58 PM

I'm sure it also depends on the mag. The mags I had a problem with the floor plates we're made by D&H, which are pretty low end GI contract.

I think I still have a pic around somewhere....

American Red Neck · June 15, 2013, 07:28 PM

ya my mags are nhmtg. i have about 8 and i have all of them loaded and have been for a couple months now and only one has about 1/32 inch difference than all the rest.

Theohazard · June 16, 2013, 03:27 AM

GI mags are fine if left loaded, the feed lips won't spread. But some mags with polymer feed lips can spread if left loaded too long. That's why PMAGs come with a cover; the plastic feed lips have been known to spread when the mag is loaded for too long and the cover is supposed to stop this from happening. Supposedly the newer PMAGs are improved enough to where this won't happen, but it's even less likely to happen with good GI mags like those from DSG.

Airborne Falcon · June 16, 2013, 04:52 AM

I'm not sure the Pmag covers are made to prevent them from splitting. They are there as dust covers and they have no lateral support that I know of.

I gave up steel mags long ago. All I used are PMags for my ARs and variants.

Palmetto-Pride · June 16, 2013, 06:06 AM

The P-Mags dust covers do prevent the lips from spreading because when they are put on the P-Mag they push down on the first cartridge taking the pressure off the feed lips.

Quentin2 · June 16, 2013, 09:42 AM

NHMTG are fine USGI mags. I wouldn't worry much about storing them loaded.

sailskidrive · June 16, 2013, 11:34 AM

I really like the new Lancers.

tahunua001 · June 16, 2013, 12:25 PM

that's just a myth. your odds of an aluminum magazine's feedlips spreading are just about the same as a plastic mags feed lips spreading. those mags were designed to be fullyloaded for extecnded periods of time. I've taken magazines that were left loaded for 10+ years and they function flawlessly.

American Red Neck · June 16, 2013, 03:58 PM

i wonder how long i can leave my nhmtg mags fully loaded before the feed lips spread. thats a weird thing them feed lips spreadin.

Dfariswheel · June 16, 2013, 07:31 PM

The P-Mags dust covers do prevent the lips from spreading because when they are put on the P-Mag they push down on the first cartridge taking the pressure off the feed lips.

That's not what Magpul says.
They say the cover is nothing more than a dust cover and to protect the top round from being damaged, and has nothing to do with preventing the lips from spreading. It's nothing more then an impact-dust cover.

I emailed them and asked. That was their response.

American Red Neck · June 16, 2013, 08:30 PM

well i put some thought into it and invented a device out of plexy glass the takes the pressure off the top round in aluminum gi magazines. if someone could tell me how to post pictures i will show you what i mean. i will put em up for sale for 3 bucks a piece, haha.

Airborne Falcon · June 16, 2013, 10:30 PM

I've got a friend that supplied us with PMags in the rock pile, works for them, got me all my PMags for my 716 ... I called him and he said no, the covers have absolutely nothing to do with keeping the lips from spreading. They are there to prevent particulate matter from invading the magazine and causing a failure to feed.

I always kept dust covers on my PMags in my mag pouches for just that reason, incase I had to go prone and my mag pouches would fill with sand or dirt.

Theohazard · June 16, 2013, 11:15 PM

Quote:

Dfariswheel posted
That's not what Magpul says.

Quote:

Airborne Falcon posted
I've got a friend that supplied us with PMags in the rock pile, works for them, got me all my PMags for my 716 ... I called him and he said no, the covers have absolutely nothing to do with keeping the lips from spreading

Of course the company won't admit it if that's the real reason for the covers.

If you're convinced it's only a myth that the Pmag's feed lips spread when left loaded without a cover, then I'll listen to actual experience or objective reviews and tests, but statements from the company aren't going to convince me.

Theohazard · June 16, 2013, 11:17 PM

Quote:

American Red Neck posted
well i put some thought into it and invented a device out of plexy glass the takes the pressure off the top round in aluminum gi magazines. if someone could tell me how to post pictures i will show you what i mean. i will put em up for sale for 3 bucks a piece, haha.

So you designed and build a device to fix a problem that doesn't exist?

American Red Neck · June 16, 2013, 11:26 PM

doesnt exist...i notice the lips spreading in 2 of my aluminum mags. it does exist and does make sense. upward pressure on the lips CAN eventually spread them and maybe even cause double feeds. i dont know about pmags spreading but i know from EXPERIENCE that the aluminum CAN spread.

Theohazard · June 16, 2013, 11:58 PM

Quote:

American Red Neck posted
i notice the lips spreading in 2 of my aluminum mags. it does exist and does make sense. upward pressure on the lips CAN eventually spread them and maybe even cause double feeds. i dont know about pmags spreading but i know from EXPERIENCE that the aluminum CAN spread.

In your other threads you also noticed that your new SIG AR-15 had a cracked bolt, a chip in the chrome lining of the barrel, and machining errors. Then it turned out none of that was true and you were worrying about non-existant problems.

I've had plenty of GI mags with feed lips spreading, but it was all due to being beaten around repeatedly and getting bent up, not due to being left loaded.

Hey, it's possible you have a few bad mags where the feed lips are actually spreading, but almost every previous post you've made here has been a complaint about a "problem" that ended up not being an issue. And you blamed SIG for selling you a faulty rifle when the only actual problem was a scratched bolt lug due to you slamming the bolt closed on rock.

Please forgive me for being skeptical.

American Red Neck · June 17, 2013, 12:31 AM

oh ya sure. i know how to use a tape measure bud. ill break it down for you. you measure brand new mags of the same brand even a couple of them to get a good base line. then you measure the ones in question and review the results. but ya i could have read the tape wrong...i doubt it though.

Destructo6 · June 18, 2013, 04:27 PM

I don't believe the feed lips on USGI mags will spread by merely leaving them loaded on a shelf.

I've seen plenty of USGI feed lips spread with use and, mostly, abuse. When they spread, toss them in the trash or mark them for training to clear double feeds.

There exists a Go/No-go tool to measure USGI style feed lips. Pretty cool when you have hundreds of magazines that need to be regularly checked. A little bit pricey if you only have a couple dozen or so.

The quick and easy is to load a few rounds into the magazine and then give the bottom a good whack: if a round pops out, the mag is likely no good. If no round pops out, take one round out of the magazine and repeat for the other feed lip.

June 15, 2013, 06:41 PM	#1
American Red Neck Junior member Join Date: May 8, 2013 Posts: 81	Ar-15 Magazine Question Hey guys so i have many aluminum ar mags. i recently read something on feed lips spreading and them being no good after that happens. my question is how long can i store these mags fully loaded before the feed lips spread to a point where the mags are no good anymore.

June 15, 2013, 06:45 PM	#2
sailskidrive Senior Member Join Date: October 26, 2008 Posts: 726	I haven't had an issue with the mag lips feeding as much as the floor plates starting to bulge on USGI mags. If you're going to store for an extended amount of time, buy some stainless steel or PMAGs. __________________ SailSkiDrive Hk USP 45 Expert, USP 40, USP 9, SIG P226, S&W M&P9, Hk 4, Makarov, Desert Eagle 40, Beretta FS92 Centurion, Kimber TLEII 1911A1, Glock 22, SIG P225, 1943 Rem Rand 1911A1, S&W mod 64, Walther PPQ, SIG P229, Browning BDA 45 (SIG P220), Hk45, SIG P230

June 15, 2013, 06:58 PM	#4
sailskidrive Senior Member Join Date: October 26, 2008 Posts: 726	I'm sure it also depends on the mag. The mags I had a problem with the floor plates we're made by D&H, which are pretty low end GI contract. I think I still have a pic around somewhere.... __________________ SailSkiDrive Hk USP 45 Expert, USP 40, USP 9, SIG P226, S&W M&P9, Hk 4, Makarov, Desert Eagle 40, Beretta FS92 Centurion, Kimber TLEII 1911A1, Glock 22, SIG P225, 1943 Rem Rand 1911A1, S&W mod 64, Walther PPQ, SIG P229, Browning BDA 45 (SIG P220), Hk45, SIG P230

June 16, 2013, 04:52 AM	#7
Airborne Falcon Senior Member Join Date: August 5, 2005 Location: Capital City, SC Posts: 138	I'm not sure the Pmag covers are made to prevent them from splitting. They are there as dust covers and they have no lateral support that I know of. I gave up steel mags long ago. All I used are PMags for my ARs and variants. __________________ What you think about, you do ... what you do, you become.

June 16, 2013, 11:34 AM	#10
sailskidrive Senior Member Join Date: October 26, 2008 Posts: 726	I really like the new Lancers. __________________ SailSkiDrive Hk USP 45 Expert, USP 40, USP 9, SIG P226, S&W M&P9, Hk 4, Makarov, Desert Eagle 40, Beretta FS92 Centurion, Kimber TLEII 1911A1, Glock 22, SIG P225, 1943 Rem Rand 1911A1, S&W mod 64, Walther PPQ, SIG P229, Browning BDA 45 (SIG P220), Hk45, SIG P230

June 15, 2013, 06:51 PM	#3
Dfariswheel Senior Member Join Date: May 4, 2001 Posts: 7,561	I left an aluminum USGI surplus magazine loaded for between 20 and 25 years. The lips did not spread, (I measured them in comparison to a new, unused magazine) and when I shot the magazine earlier this year, it fired all 30 rounds perfectly. I think the spreading lips thing is something left over from the days of cheap, non-spec magazines and early plastic mags.

June 15, 2013, 07:28 PM	#5
American Red Neck Junior member Join Date: May 8, 2013 Posts: 81	ya my mags are nhmtg. i have about 8 and i have all of them loaded and have been for a couple months now and only one has about 1/32 inch difference than all the rest.

June 16, 2013, 03:27 AM	#6
Theohazard Senior Member Join Date: April 19, 2012 Location: Western PA Posts: 3,829	GI mags are fine if left loaded, the feed lips won't spread. But some mags with polymer feed lips can spread if left loaded too long. That's why PMAGs come with a cover; the plastic feed lips have been known to spread when the mag is loaded for too long and the cover is supposed to stop this from happening. Supposedly the newer PMAGs are improved enough to where this won't happen, but it's even less likely to happen with good GI mags like those from DSG.

June 16, 2013, 06:06 AM	#8
Palmetto-Pride Senior Member Join Date: May 31, 2009 Location: Charleston, SC Posts: 2,071	The P-Mags dust covers do prevent the lips from spreading because when they are put on the P-Mag they push down on the first cartridge taking the pressure off the feed lips.

June 16, 2013, 09:42 AM	#9
Quentin2 Senior Member Join Date: June 18, 2009 Location: NorthWest USA Posts: 1,996	NHMTG are fine USGI mags. I wouldn't worry much about storing them loaded.

June 16, 2013, 12:25 PM	#11
tahunua001 Senior Member Join Date: July 21, 2011 Location: Idaho Posts: 7,839	that's just a myth. your odds of an aluminum magazine's feedlips spreading are just about the same as a plastic mags feed lips spreading. those mags were designed to be fullyloaded for extecnded periods of time. I've taken magazines that were left loaded for 10+ years and they function flawlessly. __________________ ignore my complete lack of capitalization. I still have no problem correcting your grammar. I never said half the stuff people said I did-Albert Einstein You can't believe everything you read on the internet-Benjamin Franklin

June 16, 2013, 03:58 PM	#12
American Red Neck Junior member Join Date: May 8, 2013 Posts: 81	i wonder how long i can leave my nhmtg mags fully loaded before the feed lips spread. thats a weird thing them feed lips spreadin.

June 16, 2013, 07:31 PM	#13
Dfariswheel Senior Member Join Date: May 4, 2001 Posts: 7,561	The P-Mags dust covers do prevent the lips from spreading because when they are put on the P-Mag they push down on the first cartridge taking the pressure off the feed lips. That's not what Magpul says. They say the cover is nothing more than a dust cover and to protect the top round from being damaged, and has nothing to do with preventing the lips from spreading. It's nothing more then an impact-dust cover. I emailed them and asked. That was their response.

June 16, 2013, 08:30 PM	#14
American Red Neck Junior member Join Date: May 8, 2013 Posts: 81	well i put some thought into it and invented a device out of plexy glass the takes the pressure off the top round in aluminum gi magazines. if someone could tell me how to post pictures i will show you what i mean. i will put em up for sale for 3 bucks a piece, haha.

June 16, 2013, 10:30 PM	#15
Airborne Falcon Senior Member Join Date: August 5, 2005 Location: Capital City, SC Posts: 138	I've got a friend that supplied us with PMags in the rock pile, works for them, got me all my PMags for my 716 ... I called him and he said no, the covers have absolutely nothing to do with keeping the lips from spreading. They are there to prevent particulate matter from invading the magazine and causing a failure to feed. I always kept dust covers on my PMags in my mag pouches for just that reason, incase I had to go prone and my mag pouches would fill with sand or dirt. __________________ What you think about, you do ... what you do, you become.

June 16, 2013, 11:26 PM	#18
American Red Neck Junior member Join Date: May 8, 2013 Posts: 81	doesnt exist...i notice the lips spreading in 2 of my aluminum mags. it does exist and does make sense. upward pressure on the lips CAN eventually spread them and maybe even cause double feeds. i dont know about pmags spreading but i know from EXPERIENCE that the aluminum CAN spread.

June 17, 2013, 12:31 AM	#20
American Red Neck Junior member Join Date: May 8, 2013 Posts: 81	oh ya sure. i know how to use a tape measure bud. ill break it down for you. you measure brand new mags of the same brand even a couple of them to get a good base line. then you measure the ones in question and review the results. but ya i could have read the tape wrong...i doubt it though.

June 18, 2013, 04:27 PM	#21
Destructo6 Senior Member Join Date: March 18, 1999 Location: Nogales, AZ USA Posts: 4,016	I don't believe the feed lips on USGI mags will spread by merely leaving them loaded on a shelf. I've seen plenty of USGI feed lips spread with use and, mostly, abuse. When they spread, toss them in the trash or mark them for training to clear double feeds. There exists a Go/No-go tool to measure USGI style feed lips. Pretty cool when you have hundreds of magazines that need to be regularly checked. A little bit pricey if you only have a couple dozen or so. The quick and easy is to load a few rounds into the magazine and then give the bottom a good whack: if a round pops out, the mag is likely no good. If no round pops out, take one round out of the magazine and repeat for the other feed lip. __________________ God gave you a soul. Your parents, a body. Your country, a rifle. Keep all of them clean.