MDP-9, UDP-9 and 0940 magazine compatibility
These firearms are designed to accept Glock double stack 9mm magazines. We ONLY recommend the use of OEM Glock magazines and Magpul PMAGS. While most 3rd party/aftermarket magazines will work, some may experience feeding issues, not latch properly or fail to operate the last round bolt hold open feature. ETS magazines are not compatible with any of our current platforms. The Magpul D-50 is also not compatible.
We have found Glock 15rd, 17rd, 24rd and Magpul PMAGS (except for Magpul D-50 drum) magazines to deliver the best overall performance.
High capacity magazines
When using 33 Round Glock Magazines we recommended downloading 3 rounds (e.g. 30 rounds vs 33 rounds). A fully loaded 33 round magazine spring exerts a tremendous amount of upward pressure on the bolt and feeding reliability will be improved by simply downloading 2-3 rounds. Please see this article if you are having issues with a 33rd Glock magazine.
Loading the firearm
We always recommend loading from an open bolt. If you would like to perform a tactical reload we recommend downloading the magazine 2-3 rounds. We also recommend using the bolt catch to release the bolt. "Riding" the charging handle can slow the bolt's momentum and cause rounds not to feed correctly.
Holding the magazine while shooting
Do not hold or support the firearm by the magazine or magwell. Always place your support hand on the handguard and grip tightly when shooting the firearm.
Magazines should be cleaned as often as you clean your gun. Wiping excess carbon from the follower and feed lips will improve the reliability of the magazine. If your magazine is extremely fouled, you should remove the base pad, spring and clean all internal surfaces. Magazines wear over time and will need to be replaced. A good practice is to label your magazines (A, B, C, etc.) and note if a certain magazine causes repeated issues.
We cannot troubleshoot issues caused by 3rd party magazines. If you are having magazine issues please see our Troubleshooting section.
UDP-45 and 1045 Receiver Magazine Compatibility
The UDP-45 and 1045 receivers are designed to accept 45 ACP Glock double stack magazines and we recommend the use of OEM Glock magazines only. While most 3rd party/aftermarket magazines will work, some may experience feeding issues, not latch properly or fail to operate the last round bolt hold open feature. We cannot troubleshoot issues caused by 3rd party magazines.