PMAG (GEN M3) won't insert with breech closed (M&P 15 Sport)

[OchoBlue 3]

Should an MP 15 sport accept a PMAG without first pulling back the charging handle ? I took my new MP 15 Sport to the range for the first time today (I'm new to the AR15 platform) and could insert the stock magazine no problem with the breech open or closed . The PMAG required that the breech be open / charged to accept the magazine.

 

Thanks!

[Artyguy 0]

Are these pmags blocked to 15 rounds? If they are, it may be due to how they are blocked. I bought a couple from bullseye tactical supply and they load fine with 15 rounds on a closed bolt. My buddy ordered some online (can't remember the site right now) and they do not load on a closed bolt.

 

 

 

[blksheep 466]

Its probably tight from the modification. It might loosen up with usage.

[OchoBlue 3]

Are these pmags blocked to 15 rounds? If they are, it may be due to how they are blocked. I bought a couple from bullseye tactical supply and they load fine with 15 rounds on a closed bolt. My buddy ordered some online (can't remember the site right now) and they do not load on a closed bolt.

Yes they are blocked ...

[Artyguy 0]

Yes they are blocked ...

It's more than likely how they are blocked.

 

 

 

[OchoBlue 3]

It's more than likely how they are blocked.

 

http://midwestpx.com/product_info.php?cPath=15_72&products_id=692

 

They are from MidwestPX

[Artyguy 0]

http://midwestpx.com/product_info.php?cPath=15_72&products_id=692

 

They are from MidwestPX

Never used those. So I wouldn't be able to comment on it. My buddy bought his from mtnarmory.com and those will not load on a closed bolt. Again I'm sure it's because of how they are blocked. Did you try loading 14 rounds in the mag and then see if the mag loads on a closed bolt?

 

 

 

[Poisontail 0]

Cause they are pinned to 15 and you can't even try to stick a 16th in there it's to tight it does not allow play while bolt is closed unless you totally beast it in there! Welcome to jersey ar's

[OchoBlue 3]

Never used those. So I wouldn't be able to comment on it. My buddy bought his from mtnarmory.com and those will not load on a closed bolt. Again I'm sure it's because of how they are blocked. Did you try loading 14 rounds in the mag and then see if the mag loads on a closed bolt?

Works through loading 9. At 10 no go. That was an interesting test ... Go figure ?

[MidwestPX 172]

A couple things are at work here.  First, AR tolerances are all over the place due to the large number of manufacturers and literally a nearly infinite combination of tolerance stackups.  In order to guarantee fitting against a closed bolt in every AR, I would have to allow enough room for nearly a 16th round to slip in.  If you were ham handed with it and really tried to force that 16th round, it will fit because the polymer wall of the PMAG will flex and allow it.  The mag won't work but the law is written around absolute capacity, not functional capacity.  If you look at a factory 30rd PMAG, it will actually take 31 and even then, it's still a fight to get it to fit against a closed bolt when the carbine is hot.  Do what we free staters do and download your mags.  Every class I've been in, the shooters are loading to 28 or 29 (usually 28 to keep the top round on the same side as 30) because they don't want to fight the mag when doing a tactical reload.

[NYMetsFan86 9]

so basically.. load to 14 and your gtg

[OchoBlue 3]

Download mag by one round or load on an open bolt

 

It's download by 6 (works at 9)... I'll probably go with the open bolt.

[MidwestPX 172]

Download mag by one round or load on an open bolt

That's the other thing I forgot to mention.  The platform is designed to be made ready from an open bolt meaning lock the bolt to the rear, insert mag, release bolt with the bolt catch.  For those wishing to store an AR for HD purposes with a loaded mag, do as I do and download the mag, seat it, push/pull, and store it.

[MidwestPX 172]

It's download by 6 (works at 9)... I'll probably go with the open bolt.

Say what?

[Artyguy 0]

It's download by 6 (works at 9)... I'll probably go with the open bolt.

That sounds like a really bad mag.

 

 

 

[OchoBlue 3]

Say what?

If you want to insert the mag loaded you can only put 9 rounds in. The rifle will not accept it after you put 10 in unless you open the bolt.

 

So you need to download by 6 from its stated 15 capacity.

[MidwestPX 172]

If you want to insert the mag loaded you can only put 9 rounds in. The rifle will not accept it after you put 10 in unless you open the bolt.

 

So you need to download by 6 from its stated 15 capacity.

Does it fit more than nine rounds at all?

[OchoBlue 3]

Does it fit more than nine rounds at all?

 

Yes - fits 15 as expected, but needs the bolt open to accept it with any more than 9 inserted.

[MidwestPX 172]

Yes - fits 15 as expected, but needs the bolt open to accept it with any more than 9 inserted.

That doesn't make sense.  If the follower has the vertical clearance to accept rounds 10-15, it has the same clearance to load against a closed bolt up until the 15th round.  Can you test it in another AR?

[OchoBlue 3]

That doesn't make sense.  If the follower has the vertical clearance to accept rounds 10-15, it has the same clearance to load against a closed bolt up until the 15th round.  Can you test it in another AR?

Whether it makes sense or not it's exactly what is happening.

 

I'm shooting with friends in early October so that would be the first opportunity I'll have to try it in other rifles.

[Jerseyfirefighter 0]

Ill take them off your hands if you want

[9X19 125]

Did you only buy 1 mag? Do you have another P-mag to try?

[Poisontail 0]

Just like all the pinned Midwest px mags if you put 15 rounds in the dust covers don't work to tight

[plode 0]

Give it a good hard smack on the bottom when putting it in.  I've found you can't be gentle with fully loaded mags when the bolt is closed on AR's. 

I've never had any issues with this method with full 15 round PMAG's. or fully loaded USGI 30 round mags(when out of state of course). 

[vladtepes 1,060]

Give it a good hard smack on the bottom when putting it in.  I've found you can't be gentle with fully loaded mags when the bolt is closed on AR's. 

I've never had any issues with this method with full 15 round PMAG's. or fully loaded USGI 30 round mags(when out of state of course).

 

This...

 

There is NO way you need to down load by 6 to insert a mag... You may be being too gentle with it...

[vladtepes 1,060]

I have found that some AR owners tend to treat the rifle like it is 2000 year old rare chinese pottery and not the battle rifle that it was/is mean to be......

 

I put a small scratch once on a pivot pin head while working on one for someone.............the tounge lashing that I received....WOW...

They would have a stroke if they saw how I treated guns...

[BlueLineFish 615]

Yeah......I am sure.........kinda like the clean the motorcycle thing.........a clean bike is a sign of a sick mind and that your are doing more polishing than riding........

 

I know someone who does a COMPLETE DETAIL strip of a gov 45 EACH and every time he shoots its...whether it is one round or 100 etc...talk about ADD.......yikes...

thats actually ocd..either way its ridiculous.

[plode 0]

Yeah......I am sure.........kinda like the clean the motorcycle thing.........a clean bike is a sign of a sick mind and that your are doing more polishing than riding........

 

I know someone who does a COMPLETE DETAIL strip of a gov 45 EACH and every time he shoots its...whether it is one round or 100 etc...talk about ADD.......yikes...

 

My bike is currently covered in mud.  I didn't feel like dragging the hose out last time I rode it.  Dual sport bike(DRZ-400). 

 

Oh and my AR hasn't been cleaned in over 200 rounds. 

 

Guess I don't have OCD

[bhunted 887]

Yeah......I am sure.........kinda like the clean the motorcycle thing.........a clean bike is a sign of a sick mind and that your are doing more polishing than riding........

 

I know someone who does a COMPLETE DETAIL strip of a gov 45 EACH and every time he shoots its...whether it is one round or 100 etc...talk about ADD.......yikes...

Hey hey, I resemble those remarks! There is nothing wrong with keeping your toy clean!

 

 

Sent from my iPad using Tapatalk 2 Pro

[checko 180]

Hey hey, I resemble those remarks! There is nothing wrong with keeping your toy clean!

 

 

Sent from my iPad using Tapatalk 2 Pro

Keep playing with it and you'll go blind.