[G22Dude]

I have an Arsenal SGL 21-61. Due to state laws I am limited to 15 round mags by state law. Any way I purchased a bunch of AK steel 10 rounders.

I recently loaded at least two mags with 11 rounds. and I observed that they cycled correctly into the chamber. Is this unusual?

[Glockdude1]

Very unusual , to have such strange magazine laws on the books.

J/K, your mags are fine.

[El_Ron1]

Anytime you overstuff a magazine you invite problems. There are tolerance variables from mfg. to mfg., components to components. but it's not a good habit. Most likely, the "10s" were modified 5s.

[Nicoroshi]

I also suffer from stupid round limiting laws in CA. I have found my best mags are surplus steel mags that I have fixed to only hold 10 rounds (Yep, worse off than you I am afraid).
I do this by putting a pop rivet in the mag body to stop the follower so it complies with dumb laws.
Hoping (and fighting) for one day when I can drill that pop rivet out, and load them to the 30 they were designed to hold.
The Chinese rebuild kits at Copes are $13.99, and they'll ship them as 'rebuild kits' even to my state.