I have always preferred USGI magazines, you can stock up quickly at a lower price than non-USGI magazines. When selecting your USGI magazines stick to known high-quality brands. Several are: NHMTG/Colt, D&H Industries, Brownells, and Center Industries. I mainly use NHMTG/Colt magazines, but I have been switching to D&H Industries magazines from DSG Arms. The D&H magazines with the Magpul follower can be $8.50 a magazine if you buy the ten (10) pack. Another big plus (+) I see for using USGI magazines is Magpul L-Plates.
Magpul L-Plates offer several advantages for your USGI magazines and I will go over a few of these in no particular order.
1.) I have cut myself several times in the heat of the moment with USGI magazines. USGI magazine floor plates have sharp edges and can really beat up your gear, clothing, and skin. When using open top magazine pouches on a vest or chest rig, I have cut my forearms while moving and sometimes my hands/fingers when quickly removing magazines. The rubber L-Plate quickly addresses all of these issues. They take less than a minute to install. The rubber L-Plates protect your gear, clothing, and skin from the previously mentioned sharp edges. The rubber L-Plates extend the magazine for a positive grip during magazine changes (i.e. removal from the pouch). The rubber L-Plates protect the bottom of the magazine during ground strikes that may occur during speed reloads. This added protection is especially important on harder surfaces: gravel, pavement, or concrete, and it will increase the life of the magazine.
2.) Depending on your weapon system or current role in law enforcement, the military or average citizen, you may or may not have several different types of ammunition loads. Having the ability to mark and quickly identify what type of round is in which magazine can be very helpful. The L-Plates can be used for such purposes by using a different color L-Plate to identify the type of rounds in a particular magazine. For Example, I have Hornady 75gr OTM ammunition in magazines with FDE L-Plates; Federal Tactical Bonded 55gr. ammunition in magazines with OD green L-Plates; and Federal M193 ammunition in magazines with Black L-Plates. Another example where ammunition/magazine marking proves useful is with newer rifles, like the Daniel Defense DDM4v5 300 Blackout. The 300 BLK, which uses 7.62x35mm ammunition, uses the exact same magazine as those used with 5.56mm ammunition. In this situation, marking your magazine to identify ammunition type is necessary to avoid injury and/or catastrophic failure.
3.) One of the best benefits of using L-Plates is when using the magazine as a monopod. The monopod technique provides a quick stable platform for more accurate shots with a patrol rifle. Standard USGI magazine floor plates can become scratched and/or gouged when firing using the monopod method on abrasive surfaces (i.e. brick or concrete). This in turn leads to added wear and tear on your gear, clothing, and skin. By using the L-Plates you can avoid the scratching and gouging, as well as the added wear and tear. The L-Plates can also help with recoil absorption and provide a nonslip contact point when firing from a wet/slick surface, like the hood or trunk of a vehicle.
For anyone who is concerned about malfunctions when using the magazine as a monopod, don’t worry this is a non issue in my opinion. This has been a long debated question. I started using and instructing officers on this technique almost a decade ago. Any advanced carbine course you might take, from any number of well respected schools/instructors, will teach magazine as monopod technique. If you have a feed issue or malfunction, you more than likely have a bad magazine. All magazines wear out and can be damaged, if it’s not working properly make it a training only magazine or get rid of it.
Note. There is a drawback to using L-Plates. I have found the inner locking plate for the L-Plate takes up a slight amount of room inside the magazine and affects the amount of ammunition it can hold. Technically, the magazine can still be loaded with 30 rounds but you cannot seat the magazine on a closed bolt. If you are going to be performing magazine changes with a closed bolt, and you are using L-Plates, I suggest sacrificing one (1) round to ensure the magazine is fully seated. Years ago, I got into the habit of only loading 28 rounds in USGI magazines, and I have never really stopped, so the concern identified above is really not an issue for me.
The Magpul L-Plates are a great addition to your USGI magazines. Several of the ranges I used as a police officer had paved areas, sidewalks, and some gravel areas. This environment took a heavy toll on dropping magazines during range sessions. For a law enforcement officer who operates in an urban or street environment with sidewalks, paved surfaces, fences, block walls, and vehicles, the L-Plates may provide an advantage in stability when using the magazine monopod technique. The L-Plates also save you and your gear from the sharp edges that can get you from time to time. While the L-Plates are not a necessity, they are a nice piece of gear to have.