I had a couple that I bought for my Ruger P89DC. When I bought them, I didn't know they had the clock work spring, I only knew that they advertised 18 rds and flush fit. IIRC, I bought them right before the "hi-cap mag ban" went into effect but after we all knew it was going into effect.
Overall, pure junk. I can't remember any time I actually got through a full magazine with them without some sort of malfunction. Put Ruger factory or MecGar mags in it and it was flawless. Put the Ram Line mags back in, malfs. I sold them later in the ban era to someone who wanted to tinker, fully disclosing the malf issues.
I also had a couple of polymer Ram Line AR15 mags that had the clock work spring that I bought the same time as the P89 mags. As with the P89 mags, pure junk and nothing but malfs. As with the Ruger, put in some good aluminum GI surplus mags, perfect reliability. Put the Ram Line mags in, malfs. These I still have, somewhere.
Give yours a try, what can it hurt? I'm thinking that mine were rushed to make the deadline for the mag ban, so maybe that's why they were junk. I have read that they work well for some, but poorly for most. Maybe you got a good one. Based on my experience and most of the things I have read, I wouldn't use them for serious work, but if it works, should make a decent range mag.
Bub75