MBX Mags Not Locking in PT Evo Grip

[tyler2you]

I have a strange issue.  I got one of the new PT Evo Grips on Saturday and started checking it out this weekend.  I put in my Dawson Posi Lock Mag Catch and found that 4 of my 6 MBX Mags won't lock in securely.  I can push the mag to the right a bit and it will drop past the mag catch ledge.  It doesn't take much to get the mag to drop out of the gun without pushing the button.  I can also over insert a mag.  

I tried my STI dry fire mags and they lock up without issue.  I took some width measurements with my calipers at the notch and the MBX Mags measure .910" on average and the STI Mags measure .945".  The 2 MBX mags that lock in are just a few thousandths wider than the ones that won't (.003").

I also have one of the standard PT Grips that works fine with all my mags.  I tried swapping the mag catches between grips and it didn't make much difference (CK Arms catch in the other grip).  Not sure where to go from here as I'm not going to give up the MBX Mags.  I already fit the Evo Grip to the SVI Interchangeable Trigger, so I'm stuck with it.

 

MBX Mag

 

No Mag

 

STI Mag

Edited October 24, 2016 by tyler2you

[Aircooled6racer]

Hello: I would say since all of your STI mags work fine and 2 MBX mags work fine then I would tune the 4 MBX that don't work fine. First I would give MBX a call and see what they say. I would then give PT a call and ask them as well. Have you installed the grip on the frame or just by itself? Installing on the frame may change a couple of things and it may work just fine. If not, start phoning or send an e-mail. Thanks, Eric

[teros135]

I've had problems with mags suddenly falling out of my new EVO grip as well, usually at a really inopportune time in a match, like on a classifier today.  Never happened before the grip was installed (it's on a PT frame).  I use the Dawson Posi-Lock mag release, as recommended.  I assume it's a glitch and would also like to know what the fix is.

Edited October 24, 2016 by teros135

[tyler2you]

Hey Eric.  I haven't installed the grip on the frame yet as it's out for chrome right now.  How would you tune the mags for this issue?  I don't see how you could expand the mag at the notch.

Seems like a catch with an extended ledge would fix the issue, but I don't see anyone that advertises anything like that.  May have to send it to someone for a bit of Tig.  I'll see if MBX or PT have a recommendation tomorrow.

 

 

[tyler2you]

32 minutes ago, teros135 said:

I've had problems with mags suddenly falling out of my new EVO grip as well, usually at a really inopportune time in a match, like on a classifier today.  Never happened before the grip was installed (it's on a PT frame).  I use the Dawson Posi-Lock mag release, as recommended.  I assume it's a glitch and would also like to know what the fix is.

Are you using MBX Mags?

[teros135]

1 minute ago, tyler2you said:

Are you using MBX Mags?

Yes.  Doesn't seem to happen with my STIs, but I only use them in practice (38SC). 

[CHA-LEE]

I have the old style PT grips and I had to increase the engagement depth of the mag release ledge on every one of them when using the MBX mags. You need to lower the shoulder on the left side of the mag release so it can move deeper into the mag catch notch of the mag. I suspect that the new EVO grip needs the same type of modification.

[teros135]

11 minutes ago, CHA-LEE said:

I have the old style PT grips and I had to increase the engagement depth of the mag release ledge on every one of them when using the MBX mags. You need to lower the shoulder on the left side of the mag release so it can move deeper into the mag catch notch of the mag. I suspect that the new EVO grip needs the same type of modification.

Thanks, Cha-Lee.  I'll give that a try. 

(Aren't 2011s fun?  You get to learn all kinds of new skills.)

[tyler2you]

Thanks Cha-Lee.  That worked.  I took off a bit more than I needed to, but I think it will work.  Only drawback is that it recesses the catch a bit on the right side (cosmetic).  All of my mags lock up solidly now.

 

[CHA-LEE]

My mag catches look about the same depth on the right side as yours.

[kcd19]

This topic is of interest to me as well since I am weighing the purchase of the PT Evo.  A couple of clarifications, though..

8 hours ago, CHA-LEE said:

I have the old style PT grips and I had to increase the engagement depth of the mag release ledge on every one of them when using the MBX mags. .

Could you elaborate?  By adding material to the ledge?  Tig?  Or something else?

 

8 hours ago, CHA-LEE said:

You need to lower the shoulder on the left side of the mag release so it can move deeper into the mag catch notch of the mag. I suspect that the new EVO grip needs the same type of modification

 

I think I follow this -- effectively you're creating more relief on the shoulder (outside the frame, left-hand side) so that the release will travel further into the frame in order for the newly extended ledge to clear the mag body, right?

Thanks!

[MemphisMechanic]

You're filing a little off the ledge on the "thumb button side" of the magazine release, so the spring can push the entire thing further out the left side of the gun.

The button sits up a bit higher under your thumb, and the opposite side (which they posted a photo of) ends up slightly below flush... which causes the ledge that retains the magazine to protrude farther into the magwell.

All you need is a file.

[Edge40]

This is interesting.  I had an Edge with a extreme shooters grip.  My mag release was the dawson IDPA length with the STI paddle.  I had to turn the paddle up a bit with the edge to prevent accidental mag release.  Then I got a gun with a old style PT grip and I'm having issues with the mags dropping.  I kind of need the paddle to efficiently drop mags.  I'm now wondering if the engagement with the PT grip is to little.  Now that I really think about it it does feel like its really light to drop the mags.  I just ordered a heavy mag release spring.  We'll see if that helps.  Good thread I may have to do CHA LEEs trick.  

[kcd19]

13 hours ago, MemphisMechanic said:

You're filing a little off the ledge on the "thumb button side" of the magazine release, so the spring can push the entire thing further out the left side of the gun.

The button sits up a bit higher under your thumb, and the opposite side (which they posted a photo of) ends up slightly below flush... which causes the ledge that retains the magazine to protrude farther into the magwell.

All you need is a file.

makes sense.  think i had it backward in my head on first read.  thanks for the detail.

[teros135]

I took a look at my EVO grip and the STI and MBX mags tonight.  The MBX mags just barely engage with the Dawson Posi-Lock mag release push it outward only minimally while you're sliding it up into the magwell and it clicks in.  The STIs push the mag release out a lot more and seem to create more engagement.  Like the OP, my MBXs are about .906" wide at the mag release slot and the STIs are more like .935".  It seems like a strong breath of wind could release the MBX, or perhaps recoil or brushing the mag release inadvertently. 

This is an interesting design glitch, and somewhat unfortunate.  Some people will get lucky and theirs will work.  Others will have mag drop-outs and have to cob up a good mag release an hope it works.  Glad to know it's probably not me, but that's not very reassuring.  Not sure I'll be using any more steel grips - as nice as they are, having mags fall out costs more time on a stage than the extra stability is worth.

 

[teros135]

BTW, has anybody heard from PT or MBX?  What's their take on this?

[tyler2you]

3 minutes ago, teros135 said:

BTW, has anybody heard from PT or MBX?  What's their take on this?

The fix Cha-Lee suggested was such an easy and effective fix, I didn't bother calling either MBX or PT.  About 10 minutes of careful work with a file and all is good.

[echotango]

I did what Cha-Lee suggested and no issues.  

[CHA-LEE]

14 hours ago, teros135 said:

I took a look at my EVO grip and the STI and MBX mags tonight.  The MBX mags just barely engage with the Dawson Posi-Lock mag release push it outward only minimally while you're sliding it up into the magwell and it clicks in.  The STIs push the mag release out a lot more and seem to create more engagement.  Like the OP, my MBXs are about .906" wide at the mag release slot and the STIs are more like .935".  It seems like a strong breath of wind could release the MBX, or perhaps recoil or brushing the mag release inadvertently. 

This is an interesting design glitch, and somewhat unfortunate.  Some people will get lucky and theirs will work.  Others will have mag drop-outs and have to cob up a good mag release an hope it works.  Glad to know it's probably not me, but that's not very reassuring.  Not sure I'll be using any more steel grips - as nice as they are, having mags fall out costs more time on a stage than the extra stability is worth.

 

Adjust the mag release depth as I have already defined and its no longer an "Issue". Every gun needs to be tuned and adjusted to function properly, especially when you are using a combination of parts from multiple different manufactures. Expecting multiple different manufactures parts to work with one another in any combination that also guarantees functionality with no modifications needed will always set yourself up for disappointment. Tune the parts as need to make them work, or stop using combinations of parts that are on the edge of being compatible.

[echotango]

Fit the mag release just as you had to fit the grip.  Do not expect bolt-on and go. 

[teros135]

Now you tell us!  Didn't know before about mag release fitting.  Good info.

And just to check, it's the small (.060"?) shoulder on the left side of the shaft, that one that stops the mag release from sliding out of the grip, that is filed?

[CHA-LEE]

2 hours ago, teros135 said:

Now you tell us!  Didn't know before about mag release fitting.  Good info.

And just to check, it's the small (.060"?) shoulder on the left side of the shaft, that one that stops the mag release from sliding out of the grip, that is filed?

Yes. That shoulder is what sets the overall depth of the mag catch within the grip.

[teros135]

2 hours ago, CHA-LEE said:

Yes. That shoulder is what sets the overall depth of the mag catch within the grip.

In it's usual, "sloppy" position the mag catch seems the allow the mag to find it's own center in the magwell and allow the cartridge to feed straight up the feed ramp.  With this new adjustment, did you find that you can take the shoulder back too far and cause the mag to be pushed off center (out of line with the feed ramp)? 

[tyler2you]

39 minutes ago, teros135 said:

In it's usual, "sloppy" position the mag catch seems the allow the mag to find it's own center in the magwell and allow the cartridge to feed straight up the feed ramp.  With this new adjustment, did you find that you can take the shoulder back too far and cause the mag to be pushed off center (out of line with the feed ramp)? 

Yep, unfortunately I think I took mine back too far and it's pushing the mag to the left.  Guess I'll order a new mag release and try again.

[teros135]

10 minutes ago, tyler2you said:

Yep, unfortunately I think I took mine back too far and it's pushing the mag to the left.  Guess I'll order a new mag release and try again.

Ultimately it's probably "does it work".  

The more elegant solution might be to look at the little ledge on the right side (that holds the mag) and see how much shelf doesn't have wear marks.  Measure how wide that is, and file off that much from the shoulder on the left side.  That should allow the mag to sit fully on the shelf.  Adjust from there as needed.