I know you are all very knowledgeable about other firearms, but when it comes to the 597 you guys really need to drop by rimfirecentral.com's Remington forum and learn a thing or two about the 597.
Some of the posts here read like folk trying to put out a fire by pouring gasoline on it !! You are doing the exact opposite of what the 597 needs and then you complaint that it doesn't work !
Most jams on the 597 are caused by very tight guide rod screws and/or gummed up extractors, plus too much lube.
For starters, the 597's action, by design, has very little friction and so it likes very little lubrication. A drop of oil on each guide bolt, or better yet, dry lube, and perhaps some lube on the trigger linkage components are all that's needed. Don't use grease on the guide rods, or slather them in oil, and please don't clean the action with WD-40 ! Excess lubricant tends to collect powder residue, and that increases friction rather than reduce it. Don't lube the magazines, either.
The bolt-face, in particular, should be kept lube-free, especially around the extractor because lube will collect crud and gum up the extractor. When I bought my 597 a few years back I ordered a VQ exact-edge extractor because I heard the 597 may have extraction problems. Several thousand rounds later, I can count the number of jams that I've had with my fingers, and still have fingers left. The VQ extractor has been completely uncessary and it's still collecting dust in it's original package. The factory extractor is more than adequate to fling empties with authority as long as you don't crud it up with lube.
The guide rods, strong as they are, can still bend under pressure. Though the bend is so slight that it's impossible to see with the naked eye, these bent rods can cause the bolt to seize or work slugishly. Back up the guide rod screws until they barely touch the rods and ignore the manual's torque recommendations.
My 597 was built early 2003. It has digested several thousand rounds of all kinds of ammo very reliably (subsonics, HV, hyper-velocity, etc), and on a typical range session I put about a brick's worth of ammo through it without a hiccup. It shoots very small, ragged groups, too.
The 597's design is very sound and reliable, but it's also a substantially different design that that of traditional blow-back autoloaders. It just has to be maintained differently than traditional autoloaders, too.