REVIEW - Magpul PMag 35 rd for CZ Scorpion Evo 3

[Naphtali]

I should add two additional important Scorpion-specific points, dealing with normal functioning of the gun itself and Magpul's mags, after talking with CZ and Magpul.

If you have no magazine inserted (or an OEM mag), and you're manually cycling the bolt, there is a visible / palpable point of resistance near the middle of the travel range. This is where the bolt comes into contact with the hammer, and is normal per CZ. You can see this in my 1st video with the OEM mag inserted. The bolt will never completely stop / get caught on the hammer though.

Since the Magpul mags are slightly taller than OEM above the mag catch indentation, and the Magpul mag catch itself is slightly higher-positioned than OEM catch, the combination results in the top of Magpul's feed lips sitting higher in the gun (vs OEM-only parts).

Due apparently to "light contact" of the bolt across the top of the feed lips, using a Magpul mag increases felt resistance on the bolt in the region where it's passing over the hammer and magazine, compared to an OEM mag. But it shouldn't file down the feed lips in any meaningful way or be able to stop the bolt.

I interpreted this additional mild increase in bolt resistance (in the Scorpions not tested in the video) as a lesser-version-problem of the total stoppage seen in the worst-affected gun (the one in the video). Magpul, however, says this is not the case. The additional increase in bolt resistance at this point in travel is normal / known to them, and it should not affect function.

So while I thought I had a 100% rate of problems, it appears that only one Scorpion actually had a problem.

[Naphtali]

Accidental duplicate post - ok for a moderator to delete this.

[SPQR476]

Just wanted to update this as to where we are at. I have listened to the CS call, corresponded with Naphtali, we have gone back to CZ and gone through revisions and version control updates back to origins, and looked at additional samples. Here are the takeaways:

1. CS: After listening to the call and corresponding with Naphtali, there were some misunderstandings that we cleared up. The CS rep, when asked for who to talk to that was the most knowledgeable person on the Scorpion program, replied "you can talk to me". We always have CS start the process and include further tech support engineering, and PM support as needed, so while this is the correct place to start for internal process, I can understand interpreting the reply differently.

2. Test Guns: The 3 guns mentioned were validation samples from the test lot that are available for CS reference, not the total sample lot, but also, easily misinterpreted in the flow of the conversation. We use sample sizes that are commensurate with military testing and validation protocols, at a minimum, and that are in most cases significantly larger. Of note is that this phenomenon has not manifested in the entire lot of sample firearms that we used, which was extensive, and included firearms within several hundred of Naphtali's problematic gun. It also has not manifested in any of the firearms used by CZ in their testing.

3. Data and changes: We went back through all the historical TDP dimensions for all generations of the EVO 3, and even with worst case tolerance stacking it should not be possible for interference to occur in any revision that we've seen. As with anything man made, exceptions may occur.

4. Dimensions: We are indeed taller from mag catch height to feed lip top. That is intentional for improved feed geometry and thicker feed lips. It results in improved reliability in high volume testing. Our mag catch is also a hair taller than the factory catch, to improve stability with factory mags and optimize stability with ours. It appears that in Naphtali's case, the combination adds up to juuuuust interfere. Our polymer doesn't compress, and two objects can't occupy the same space at the same time, even if it's a few thousandths. Anyone that does have this problem with the combination of our mag catch and our mags can probably take a hair of the top of the mag catch with a file stroke to get it back to the same as factory mag catch height and it should go away. We haven't been able to duplicate the interference in the first place to even vet that out, but it should solve the problem in this case.

5. Other instances: For right now, we're keeping an eye on other complaints and tracking data. It appears that all instances of questions of fit have boiled down to: Naphtali's as an outlier, customers having issues loading on a closed bolt after stuffing 36 rounds into the magazine (obviously creates an issue), and aftermarket mag catches that are even taller than ours. It has been common to add a few thou to the nose of the mag catch for the very reasons we did, but some added more than we were comfortable with, and while they work with factory mags, it appears that the increased presentation height of our mags can cause interference in a few cases with those aftermarket mag catches. In most cases, and in all test samples here, they fit fine. In any case adjusting mag catch height or swapping mag catches would solve the problem here, also. Any minor scrubbing or contact that creates scuffing will be fine and does not create an issue, as we tested this when magazines are biased as when using a magazine grip, pushing or pulling or adding lateral pressure. The reduced energy required to feed the round from the improved geometry offsets any drag.

We will continue to monitor, and I encourage anyone with any issues to call CS, but for now, it appears to be an exceptionally rare case where any interference could even possibly occur. Thanks to Naphtali for working with us in gathering information to help identify the source of the issue he was experiencing.

[ndmiller]

Thank you for the update, as a Magpul buyer and CZ Scorpion owner, I understand things happen. Explanations like this (clear, factual with examples and specifics) make buying from Magpul and other accessory makers who act similarly a pleasure.

Hate to muck up the thread, but are these Evo Mags going to be offered in Sand or other colors? Sorry had to do it.

[Wake27]

Thanks for the response Duane, good to see that the original post was valid and its being worked.

[Waylander]

I was holding off on buying these mags but Magpul going above and beyond as their usual SOP for many years hasn't failed to impress. Not only by their testing sample size but I've watched their timeline on the release. While some people were disappointed in the final release date compared to other manufacturers, I go back to the old adage, "all good things come to those who wait."

[Naphtali]

I received a request to test swapping the lowers of different Scorpions, to better define the source of the problem.

I would not have predicted this... the problem follows the Upper. It does not follow the lower. It does not follow the bolt when swapped alone.

A "good" lower + the "bad" upper will fail exactly as described previously. The "bad" lower + a "good" upper works as Magpul says is intended.

I then wondered it maybe the bolt was out of spec (the "bad" bolt being too tall), so I returned the guns to their original configuration, only with the bolts swapped. A "good" bolt + "bad" upper + "bad" lower fails. The "bad" bolt + "good" upper + "good" lower works.

I guess the "bad" upper's mating surface / cutout (yes you can laugh) and its takedown pin hole are cut slightly too high in the upper, leading to the entire lower sitting too high within the upper?

Also, just got a bunch of the CZ windowed mags today (part # 11355 with the different polymer from CZ's standard mag, where the feed lips crack), and all function fine at home (no live fire). Will see if these feed lips crack when I leave several of them loaded to 30 or 29 indefinitely, to test both the left & right feed lips. I didn't know this until this week, but you can order 922r compliant floor plates and followers from CZ for these (their original mags and these windowed mags use those same parts).

I'm returning the PMags on Saturday 11-2-19, so any other requests by 11-1 would be great.

[PeteMe]

Had the same significant insertion difficulties as Naphtali with magpul mags in my evo, which I’ve had for a few years. Has the factory mag release. I filed a very small amount from the top of the feed lips. Also removed a small amount from the mag locking lug which the mag release catches on. Took a very very small amount off. Looks like scuff marks. They now insert fine. Need to test them out. Already ordered some more.

[PeteMe]

LOL, must have had the same response as Naphtali when I initially inserted them. I love the evo. The weakest point was the magaziines. Haven’t had problems with cz factory mags, the original clear ones. But would rather have PMAGs for it. FYI, got some newer black window factory cz mags a while ago and they didn’t seat either. Had to send them back. Must be mine is pre mold change. I’m fine with PMAGs if all I have to do is essentially lightly sand a few surfaces first.

PS: Mr Liptak, can use please make some 20 rounders

[Nightvisionary]

After reading through all this there are several members that should man up and deliver an apology to the OP.