I own a 597 and it is very accurate but very unreliable.
There are two main causes for it unreliability, the magazines and the extractor.
The magazines are made of die-cast aluminum and are unfinished, they get dirty and crud-ed up from the ammo and also from powder residue. This causes the rounds to not strip off the mag consistently causing mis-feeds. One of the remedies I found was to clean the the mags periodically with a brass brush to polish them and remove any crude and oxidation. But this is a PITA!!!
The stock extractor is a cheep piece of stamped steel with a machined edge that wore out in about 600-800 rounds. It would hold onto the case for just a bit slowing the timing and then stove piping when the bolt closed. I replaced the extractor with a Volquartsen extractor and that made a huge difference.
When shooting decent ammo there is more consistency and I don't get as many stove pipes. However when I shoot bulk box ammo (Federal, Remington and Winchester) the rounds are not as consistent throwing the timing off causing more stove piping.
Since this gun is a POS I don't feel bad about messing around with it trying some different ideas out on it. So I replaced the recoil buffer with very hard one trying to slow the timing down. It has seemed to work.
Now I back to the crappy magazine feeding issues.
I hope I didn't ramble to bad.
