I don’t know many details, this was PM’d to me last night on another site. A friend has a 204 Ruger chambered upper, it runs perfectly with GI mags. I passed the word on the 20 round P-mags and he picked up a couple to try. He sent this pic, they just won’t chamber from a p-mag.
Anyone have any ideas or ever heard of this.
Pmags have a different cartridge approach angle than USGI. If it doesn’t work, tell him to stick to what does.