Magazines are an often overlooked part of the weapon system and frequently a cause of malfunctions. There are a few good magazine choices and many wrong ones. While many will work fine new, how well they hold up to abuse will determine how long it will last. The most important role of the magazine is feeding rounds properly. There are other important factors, but if it cant do this one job right, it’s useless regardless of whatever cool grabbing texture or other features you add to it.
The magazine needs to consistently deliver the round to a specific location at the right angle in order for the bolt to strip and feed it properly. If its not just right, the bolt won’t strip the round, or if it does, it can happen by means of friction which leads to the round being jammed halfway into the chamber.
Bolt velocity has a role to play in this as well since too much bolt velocity (like in many overgassed guns) can overrun the ability of the magazine to feed as it should. If you are having feeding issues try a different magazine first. Remember that mags are a wear item so usage should be tracked and don’t be afraid to chuck it or relegate to a training mag to help keep your remedial action skills up. Just be sure you mark it so it doesn’t end up with your duty kit.
I recommend Magpul PMAGs or any USGI style magazine from a good manufacturer like Colt Firearms or SureFeed Magazines.