Probably because they don't work reliably. I've found the McCormick 10 rounders to be somewhat problematic in my guns. It would be nice to have a reliable high-cap mag for a single stack .45. Who was the manufacturer of these 15 rounders? Thanks.
Those were 15 round magazines, not clips. Clips are used to load magazines on some firearms such as Garands. The magazines in question are not quality anything. Saying they are not reliable is probably a very kind statement.
I saw those same 15 rounders. Man those would REALLY stick out from the bottom of the pistol.
I don't think they would be reliable.
Did you see the guy selling M1s witht he certificates from the CMP right there? I thought that was pretty poor judgement on his part. Maybe I'm wrong, but those are not meant for gun sellers to make a profit on.