Mag Won't Drop When Slide is Locked

[anonymouscuban]

Hey all,

Issue I'm having with one of my SP-01 manual safety. 

Mag will not drop freely when the slide is locked or if the slide is removed. They drop freely when in battery.

- Happens with all mags, whether empty or with rounds in the mag.
- Also happens with and without round chambered.
- Have S2 mag release installed.
- Mecgar brand mags

Appreciate help.

Sent from my SM-G930U using Tapatalk

[Earl Keese]

Are you pressing and releasing, or pressing the button and holding it.

[anonymouscuban]

Are you pressing and releasing, or pressing the button and holding it.

Pressing and releasing. Its definitely not the mag release itself hitting the mag.

Playing with it now with the slide removed, I can see that the back lip of the mag is making contact with the face of the sear cage. Enough to hold the mag in place. If I put a small amount of downward pressure on the mag follower, the mag drops out as expected. With the slide on and I'm battery,  there is downward pressure like this on the follower.

Now, I recently did the mod to the #19 pin where you add a longer pin to shim the sear cage to remove the slop or movement when you pull the trigger. It could be that this is pushing the sear cage forward a little bit and that is holding the mag in place. Gonna remove the pin and use the stock to confirm or rule this out.

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[Earl Keese]

Are you pressing and releasing, or pressing the button and holding it.

Pressing and releasing. Its definitely not the mag release itself hitting the mag.

Playing with it now with the slide removed, I can see that the back lip of the mag is making contact with the face of the sear cage. Enough to hold the mag in place. If I put a small amount of downward pressure on the mag follower, the mag drops out as expected. With the slide on and I'm battery,  there is downward pressure like this on the follower.

Now, I recently did the mod to the #19 pin where you add a longer pin to shim the sear cage to remove the slop or movement when you pull the trigger. It could be that this is pushing the sear cage forward a little bit and that is holding the mag in place. Gonna remove the pin and use the stock to confirm or rule this out.

Sent from my SM-G930U using Tapatalk

You probably need to shorten the pin a little bit. You should have a tiny bit of play between the sear cage and pin/frame.

[timmy75]

Hey all,

Issue I'm having with one of my SP-01 manual safety. 

Mag will not drop freely when the slide is locked or if the slide is removed. They drop freely when in battery.

- Happens with all mags, whether empty or with rounds in the mag.
- Also happens with and without round chambered.
- Have S2 mag release installed.
- Mecgar brand mags

Appreciate help.

Sent from my SM-G930U using Tapatalk

I had the same problem. Check if trigger bar spring is at the same distance at booth sides. too loose or too tight screw could move spring to one side or another.

[M1A4ME]

If the slide release, in the "rest" position makes enough contact with the mag. follower to help push the magazine out (or at least break it loose from the contact point inside) then it's not "stuck" very hard.

Should be too much metal to remove from the front of that sear cage.

When I worked on my Pre B CZ85 to get it to use newer magazines I read it was usually contact with the front of the sear cage that caused the rub/hang up problem, but found on mine it was just the back of the frame below the sear cage.  I didn't remove any metal from the sear cage at all.

[anonymouscuban]

Hey all,

Issue I'm having with one of my SP-01 manual safety. 

Mag will not drop freely when the slide is locked or if the slide is removed. They drop freely when in battery.

- Happens with all mags, whether empty or with rounds in the mag.
- Also happens with and without round chambered.
- Have S2 mag release installed.
- Mecgar brand mags

Appreciate help.

Sent from my SM-G930U using Tapatalk

I had the same problem. Check if trigger bar spring is at the same distance at booth sides. too loose or too tight screw could move spring to one side or another.

I just came to post that I got it fixed and then read your post. This was the root cause. The trigger bar lifter spring was bent inward a little too far on the right side. This was causing it to make contact with the very top of the mag. When the slide is in battery, it pushes down on the mag enough for it to release. However, with the slide out of battery or removed, there is no downward pressure on the mag so the spring contact held the mag in place.

The nice part is I took a little time to tune the lifter spring while I was at it and now my SA reset is really crisp.

Thanks to all the replied.



Sent from my SM-G930U using Tapatalk

[Earl Keese]

Hey all,

Issue I'm having with one of my SP-01 manual safety. 

Mag will not drop freely when the slide is locked or if the slide is removed. They drop freely when in battery.

- Happens with all mags, whether empty or with rounds in the mag.
- Also happens with and without round chambered.
- Have S2 mag release installed.
- Mecgar brand mags

Appreciate help.

Sent from my SM-G930U using Tapatalk

I had the same problem. Check if trigger bar spring is at the same distance at booth sides. too loose or too tight screw could move spring to one side or another.

I just came to post that I got it fixed and then read your post. This was the root cause. The trigger bar lifter spring was bent inward a little too far on the right side. This was causing it to make contact with the very top of the mag. When the slide is in battery, it pushes down on the mag enough for it to release. However, with the slide out of battery or removed, there is no downward pressure on the mag so the spring contact held the mag in place.

The nice part is I took a little time to tune the lifter spring while I was at it and now my SA reset is really crisp.

Thanks to all the replied.



Sent from my SM-G930U using Tapatalk

Did you re-stake that screw when you reassembled?

[anonymouscuban]

Hey all,

Issue I'm having with one of my SP-01 manual safety. 

Mag will not drop freely when the slide is locked or if the slide is removed. They drop freely when in battery.

- Happens with all mags, whether empty or with rounds in the mag.
- Also happens with and without round chambered.
- Have S2 mag release installed.
- Mecgar brand mags

Appreciate help.

Sent from my SM-G930U using Tapatalk

I had the same problem. Check if trigger bar spring is at the same distance at booth sides. too loose or too tight screw could move spring to one side or another.

I just came to post that I got it fixed and then read your post. This was the root cause. The trigger bar lifter spring was bent inward a little too far on the right side. This was causing it to make contact with the very top of the mag. When the slide is in battery, it pushes down on the mag enough for it to release. However, with the slide out of battery or removed, there is no downward pressure on the mag so the spring contact held the mag in place.

The nice part is I took a little time to tune the lifter spring while I was at it and now my SA reset is really crisp.

Thanks to all the replied.



Sent from my SM-G930U using Tapatalk

Did you re-stake that screw when you reassembled?

I did not. Never have before. Recommended?

Sent from my SM-G930U using Tapatalk

[Earl Keese]

Hey all,

Issue I'm having with one of my SP-01 manual safety. 

Mag will not drop freely when the slide is locked or if the slide is removed. They drop freely when in battery.

- Happens with all mags, whether empty or with rounds in the mag.
- Also happens with and without round chambered.
- Have S2 mag release installed.
- Mecgar brand mags

Appreciate help.

Sent from my SM-G930U using Tapatalk

I had the same problem. Check if trigger bar spring is at the same distance at booth sides. too loose or too tight screw could move spring to one side or another.

I just came to post that I got it fixed and then read your post. This was the root cause. The trigger bar lifter spring was bent inward a little too far on the right side. This was causing it to make contact with the very top of the mag. When the slide is in battery, it pushes down on the mag enough for it to release. However, with the slide out of battery or removed, there is no downward pressure on the mag so the spring contact held the mag in place.

The nice part is I took a little time to tune the lifter spring while I was at it and now my SA reset is really crisp.

Thanks to all the replied.



Sent from my SM-G930U using Tapatalk

Did you re-stake that screw when you reassembled?

I did not. Never have before. Recommended?

Sent from my SM-G930U using Tapatalk

Yes, recommended. Otherwise it will back out over time allowing the spring to move. Some people will tell you to just use loctite instead, they're wrong. Staking it is easy if you have a punch or even a starter punch will work.

Sent from my SM-G970U using Tapatalk

[anonymouscuban]

Hey all,

Issue I'm having with one of my SP-01 manual safety. 

Mag will not drop freely when the slide is locked or if the slide is removed. They drop freely when in battery.

- Happens with all mags, whether empty or with rounds in the mag.
- Also happens with and without round chambered.
- Have S2 mag release installed.
- Mecgar brand mags

Appreciate help.

Sent from my SM-G930U using Tapatalk

I had the same problem. Check if trigger bar spring is at the same distance at booth sides. too loose or too tight screw could move spring to one side or another.

I just came to post that I got it fixed and then read your post. This was the root cause. The trigger bar lifter spring was bent inward a little too far on the right side. This was causing it to make contact with the very top of the mag. When the slide is in battery, it pushes down on the mag enough for it to release. However, with the slide out of battery or removed, there is no downward pressure on the mag so the spring contact held the mag in place.

The nice part is I took a little time to tune the lifter spring while I was at it and now my SA reset is really crisp.

Thanks to all the replied.



Sent from my SM-G930U using Tapatalk

Did you re-stake that screw when you reassembled?

I did not. Never have before. Recommended?

Sent from my SM-G930U using Tapatalk

Yes, recommended. Otherwise it will back out over time allowing the spring to move. Some people will tell you to just use loctite instead, they're wrong. Staking it is easy if you have a punch or even a starter punch will work.

Sent from my SM-G970U using Tapatalk

I have both types or punches.

Can you describe how to stake it or point to a resource? What do I strike with the punch? The frame? If so, where? How hard?

Much appreciated.

Sent from my SM-G930U using Tapatalk

[Earl Keese]

You strike the frame, it doesn't take much force.. You should be able to see where it was staked from the factory. You can't easily see it with the trigger bar installed.

[anonymouscuban]

Thanks Earl. Staking complete!



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[Earl Keese]

Thanks Earl. Staking complete!



Sent from my SM-G930U using Tapatalk

Happy to help!