Magazines are one of the most critical component to reliable operation of a semi-automatic handgun. For that reason, I usually stick to factory magazines even if they are a bit on the expensive side. However in many circumstances, aftermarket magazines offer benefits that the factory magazines do not.

I have a box full of SIG brand magazines for my Sig P320 pistols, but when Elite Tactical Systems Group announced that they would be producing magazines for the P320, I was interested.

ETS Group is best known for their transparent polycarbonate Glock 9mm style magazines. I have used several and found that the ability to quickly see how many rounds I have left in the magazine is a great benefit. Sure, the factory Glock magazines have witness holes, but they occasionally lie to you and they are not easy to see in low-light situations. The ETS magazines make it simple for me to see if I have enough ammunition left to demonstrate the next drill or shoot the next competition string of fire. They also make it easy for me to make sure that I have exactly ten rounds loaded when I am shooting IDPA matches.

When ETS Group took orders for the 21 round P320 magazines, I put three in the cart and checked out. ETS Group offers P320 magazine in 15, 17, 21 and 30 round capacities. I chose the 21 round magazines because I found them to be the best compromise for the full-size P320 pistols.

When the magazines arrived, I inspected them and found that one of the base plates appeared to be mis-installed. One corner was not clipped over the “rail” of the magazine base. It was a simple matter to clip it back into place. The ETS P320 magazines use Glock style base plates. I have to assume that this was a cost-saving measure for ETS, allowing them to use the same molds from the Glock style magazines. This also allows for a wide range of aftermarket extensions and base pads to be used on the ETS magazines.

I gathered up several P320 models to test the fit of the magazines. The M17, X-Five, X-Five Legion and X-Compact all accepted the magazines without issue. The slide would lock on the empty magazines, but the empty magazines would not eject on any of the pistols. To remove as many variables as possible, I tried the magazines in several bare grip modules. They would drop free from the empty grips. I then stripped the top end from one of the P320s and inserted the empty magazine in the grip. Again, the magazine failed to drop free. It appeared that the top of the magazine was just slightly to large and was wedging itself into the slide stop lever.

I was not impresses by the dry fit. The factory P320 metal magazines eject from the P320 as fast as gravity will allow even when dirty.

I then loaded the magazines and let them sit for a couple of days to test the spring in a compressed situation. I then took them to the range for a true function test.

The magazines ran well and fed the X-Five Legion. They would not drop-free while partially loaded or empty. The magazines did lock the slide back when empty reliably. Curiously, I had one instance where the round stack just stopped rising. The follower stuck and the top rounds would rattle in the magazine body.

I contacted ETS Group for comment. They stated that they believed the mags may be out of spec and that they would be happy to exchange them. They also stated that the base pad issue could have been due to improper assembly at the factory.

ETS sent me a shipping label and I sent all three magazines back for exchange. A few days later three new 21 round magazines arrived.

The smart thing to do would have been to schedule a test day at the range to see how the new magazines performed. I often do not do the smart thing. Instead, I loaded the magazines up and decided to test them during a local Steel Challenge match in my P320 X-Five Legion.

The first thing that I noticed with the the new magazines is that they were more difficult to insert when full. It seems the polymer magazine body is swelling a little under pressure and dragging on the inside of the grip. I also noticed that the partially loaded magazines would not drop-free from the grip when performing a reload with retention.

Steel Challenge matches do not generally involve slide-lock reloads unless you mis-calculate and start a string of fire with a partial magazine. This added to my surprise when twice during the match, my slide locked back. Due to the clear design of the ETS magazines, I knew that I had enough ammunition when starting the string of fire. Each time I performed immediate action (tap, roll, rack, assess) and continued the string. This issue persisted with only one of the three magazines. I quickly shuffled that one to the back of my belt and finished the match on two magazines.

I returned to the range the next day for my regular training session and ran some more drills with the ETS 21 round magazines. This time I brought the M17. My M17 is completely stock except for the addition of the Bobro Engineering mount and the Trijicon MHS red dot. I experienced the exact same issues as with the X-Five Legion.

I performed one last test on the ETS 21 round magazines. I took a partially loaded magazine and dropped it from shoulder height, onto concrete. I intentionally drop magazines so that the feed lips impact the ground first in order to evaluate the effects on the most critical portion of the magazine. Some of the more brittle plastic mags will crack and become completely non-functional. The ETS 21 round magazines shrugged it off with little more than cosmetic damage.

Conclusion:

I enjoy using ETS magazines in my Glock pistols. I truly wanted the magazines for the P320 work well. Factory magazines are fairly expensive and the ETS magazines were half the price. The added ability to see my cartridges inside the magazine is a great aid when teaching or running limited strings of fire during competition. At this time, the issues are significant enough that I will likely not purchase any more until ETS Group improves the fit in the P320.