Author Topic: What causes a weak magazine release on one mag?  (Read 300 times)

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Offline john seeley

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What causes a weak magazine release on one mag?
« on: January 11, 2019, 06:10:56 PM »
I have a bunch of mags for my PCR, but one of my brand new 10RD mags has a really weak release. When holding the PCR sideways so the grip is parallel to the ground, all of my mags pop-out a good 4-5 inches but one of them only pops out by like 1/8". I looked at it but didn't see anything different. Does that mean the mag body is distorted somehow and is this fixable?  Thanks.
« Last Edit: January 12, 2019, 10:28:46 PM by john seeley »

Offline Walt Sherrill

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Re: What causes a weak magazine release on one mag?
« Reply #1 on: January 11, 2019, 08:11:34 PM »
That problem mag may be the only one that is oversize in one of it's dimensions. 

You might try measuring the good mags and comparing one or more of them to the problem mag?   Do you have (or have access to) a micrometer.  Something as subtle as an out-of-spec  mag release notch [it's size or location] might cause a problem, too.

Offline john seeley

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Re: What causes a weak magazine release on one mag?
« Reply #2 on: January 11, 2019, 08:19:58 PM »
That problem mag may be the only one that is oversize in one of it's dimensions. 

You might try measuring the good mags and comparing one or more of them to the problem mag?   Do you have (or have access to) a micrometer.  Something as subtle as an out-of-spec  mag release notch [it's size or location] might cause a problem, too.

Thanks. Yes. I have a mic. Is the mag release notch the small holes about 2/3rds the way up on the front corners? I'll see if I can find out what 's out of spec and before I try to bend it, I'm going to call CZ. I just bought it. This mag also has a very minut dimple on the flat rear side but thought it wouldn't effect anything. I'm guessing the width (smallest dimension L to R) is too fat but I'll know when I put the mic on it. Thx.

UPDATE:  The bad mag is too wide by about .15mm at the release notches. Time to call CZ.
« Last Edit: January 11, 2019, 09:40:13 PM by john seeley »

Offline sberres

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Re: What causes a weak magazine release on one mag?
« Reply #3 on: January 12, 2019, 05:44:48 AM »
A little judicious adjustment applied to the mag body with a rubber mallet?  So long as it doesn’t cause any internal hangups to the follower.  It is a stamped metal part, after all, not a precision machined item. Might take surprisingly little persuasion to set it right.
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Offline DOC 1500

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Re: What causes a weak magazine release on one mag?
« Reply #4 on: January 12, 2019, 07:57:26 AM »
1500 grit sandpaper and then oil it.
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Offline M1A4ME

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Re: What causes a weak magazine release on one mag?
« Reply #5 on: January 12, 2019, 10:13:18 AM »
I had one, just one, of the magazines for my Tac. Sport .40 that was difficult to insert and would not drop free.

I could see, from the wear patterns, where it really rubbed in the mag. well.  I sanded those areas down a bit, wiped the metal dust off the surface of the mag. body, tested fit and repeated the sanding, wiping, testing sequence till it would go in and drop free easily.

Then I cold blued the shiny surfaces and oiled it up.

I worked great, outside at the garage in cooler temperatures.

I came inside, set the pistol and magazine on a counter in the mud room and went about my business doing other stuff.  That evening, I grabbed up the pistol and the magazine and it would no longer drop the magazine.  Thirty degrees F, or so, temperature increase between outside and inside and it was hanging up.

I took it back outside, did some more sanding/wiping/test fitting and then cold blued it again.  Brought them both back inside, let them warm up and everything was good.

I just mentioned the above to demonstrate how a temperature change can affect fit/function when tolerances are tight.

Magazine after sanding.



Magazine after cold bluing and wiping down with an oily cloth.  The sanded surface is rougher and the cold bluing isn't nearly as dark/shiny.


Better to have it and not need it, than to need it and not have it.  So, if you see me walking the dogs with my SIG 556R, its okay.

Offline john seeley

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Re: What causes a weak magazine release on one mag?
« Reply #6 on: January 12, 2019, 12:36:35 PM »
Cool. Thanks so much for the replies.  I can definitely see scratches on this brand new mag where it's tight... more scratches than my older mags. The scratches run right along side the release notches on both sides. Offers some hints as to the areas to sand or persuade. I will respond back to let you know how I made out. Thanks again.

One thing I noticed with this 10rd mags. They're extremely finicky when trying to reseat the floor plate. The Base Lock underneath slides all over the place because there's so much play and the way it's attached to the spring. Nothing like the Base Lock of the normal capacity mags.
« Last Edit: January 12, 2019, 12:50:04 PM by john seeley »

Offline RSR

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Re: What causes a weak magazine release on one mag?
« Reply #7 on: January 12, 2019, 11:23:28 PM »
Potential for mag spring issue too, and w/ 10 rounders the potential for spring to be binding or other issues w/ the limiter insert.  Importantly, with empty mag, the mag spring pushes the mag follower into your mag release/last shot slide hold open lever which locks back the slide and provides enough tension to eject the mag. 

Offline john seeley

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Re: What causes a weak magazine release on one mag?
« Reply #8 on: January 13, 2019, 11:01:28 AM »
OK thanks.  I'm looking closely at the 10RD springs. Other than the fact that they look symmetrical, I did notice a slight difference on the ends of all of the 10RD springs. The last turn on the springs are flat or level on one end and the other end is SLIGHTLY skewed. Other than that, they look symmetrical. I think it would be better to put the flat end of the spring on the follower and the crooked end on the Base Lock.  Seating those 10RD base plates to engage the pin on the Base Lock is a PIA.

The mag that barely releases is fatter as demonstrated by the scratch marks on the side. I may put it in a padded vise and place ever so slight pressure on it. If not, I'll sand it like others suggested. Thx.
« Last Edit: January 13, 2019, 11:10:08 AM by john seeley »

Offline M1A4ME

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Re: What causes a weak magazine release on one mag?
« Reply #9 on: January 13, 2019, 01:12:06 PM »
The coiled end on one end is angled to push the front of the follower up - so there is additional upwards pressure towards the front of the bullet vs. the rear.  It's a feeding thing.

So, angled end up/forwards, flat end down on the magazine base plate.
Better to have it and not need it, than to need it and not have it.  So, if you see me walking the dogs with my SIG 556R, its okay.

Offline john seeley

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Re: What causes a weak magazine release on one mag?
« Reply #10 on: January 13, 2019, 01:56:48 PM »
Not to split hairs, but I meant the other direction. When looking at the spring from the front, you can see the last turn in the spring slops upwards to the right.. The other end of the spring is flat in that regard. It's probably unintentional but it's like that on all of my 10rd springs.