Re: .22 Magnum semi-auto rifle
I have a 597mag and love it. I picked it up used for $275 in 2006 and have probably put 1K+ rounds through it with only feed issues. This is my go-to groundhog gun when I walk the ditches.
The feed issues only seem prevalent with extra-hot loads. Zero problems with Super-X, rare problems with CCI FMJ. The CCI JHP+V's jam like crazy though. There is a large rubber recoil buffer in the rear of the receiver which throws the bolt forward too fast with the hotter loads.
Beyond that, I love the .22WMR cartridge in this rifle. Better stopping power than a .22LR, but less danger of ricochet for my particular use. My guess would be that OBD's occur primarily under rapid fire. If high-volume of fire is your goal, I don't recommend the cartridge at all. It is a small, narrow, straight rimfire case with thin walls- not ideal for fast feeding, especially out of a double-stack mag.
*See this possum, with pair of bells on*