Very informative information on this thread, I will stick around to learn and share information in regards to the S&T Type 64. I initially was planing on building a Type 64 DMR Variant (M1D scope and check rest) but after opening the gearbox and hop-up unit I kind of gave up on the ideal. However if anyone has information about the nozzle and hopup unit it would be greatly appreciated. At the current time I am not sure if the nozzle is proprietary, having a O ring Air nozzle would improve compression by a long shot. Hopup arm and bucking is strange and seems proprietary, bucking is a standard AEG but the nub was something else and badly shaped. Installing a flat hop or even a regular AEG nub will require some DIY. About Magazines they are proprietary to the gun and somewhat expensive. Changing the magazines on the Type 64 takes some manual dexterity and muscle memory. You have to get a feel for lining the feed hook in the mag well to the hole in the front of the magazine. Normally the procedure is to put the magazine in a 130° and rock backwards until you hear a click. This sound is the magazine well locking with the front hole in the magazine. Next you rock the magazine backwards until you hear the click of the magazine catch locking the magazine in place. It doesn't hurt to push the magazine forward to check if the magazine is properly seated. If the front hook has not latched onto the magazine, the magazine will move very freely in the magazine well and may fall out. Common I've noticed is in the heat of battle to either not lock the magazine in place properly or trying to put the magazine in backwards.