Magazines for a Polymer80 build: what each frame actually takes
A finished Polymer80 frame feeds from the same magazines as the Gen 3 Glock it copies. The confusion starts because the frames are sold by Polymer80 model number and magazines are sold by Glock model number. Here is the mapping.
By frame
- PF9SS takes Glock 43 magazines, 6 rounds of 9 mm. G43X and G48 magazines are longer in the body and will not seat.
- PF940SC takes Glock 26 magazines, 10 rounds. It also runs G19 and G17 magazines, which stand proud of the grip; a sleeve closes the gap.
- PF940C takes Glock 19 magazines, 15 rounds, and any longer G17 magazine.
- PF940v2 takes Glock 17 magazines, 17 rounds, and the longer G18, G34 and drum patterns. It does not take G19 magazines.
- PF45 takes Glock 21 magazines in .45 ACP and Glock 20 magazines in 10 mm. These are not interchangeable with each other even though the frame accepts both slides.
Aftermarket magazines
Magpul, ETS, KCI and similar makers label by Glock model, so the table above applies unchanged. Extended baseplates and +2 floorplates change capacity, not fit.
The magazine catch
The catch comes in the lower parts kit, not the frame kit. A worn or badly moulded catch is the usual cause of a magazine that drops free on its own, so if you are reusing parts from an old build, replace this one.
AR magazines
The RL556v3 and G150 lowers take any STANAG AR-15 magazine. The LR-308 takes SR-25 pattern magazines; DPMS and Magpul both make them, and the older Armalite pattern will not fit.
This is general information, not legal advice. Laws on unfinished frames and receivers vary by state and city and change often. Check the current law where you live before ordering.
