Its a pretty old design that seems to have not had any big changes. You can even buy a few parts to basically turn a K32 into a K80. I would like to know how the current k80 differs from the old M32 Remington. I guess if it ain't broke don't fix it. It would be nice if they could figure out how to use fewer springs. The inside of them looks like a swiss watch.
Krieghoff has constantly upgraded their K-80 gun over the years. The most visable of course is the late model Trap Special design. They have constantly made little improvements to the gun as they determined what they needed to be. I suggest you contact Krieghoff to get a better and more accurate picture of them then what you'll get here. I can only say from my experience, the Krieghoff was quite prone to breakdowns in the mid 80's. I remember being at the Grand watching shootoffs and seening several breakdown. I remember saying I now see why they are open later then everyone else, they need to be to fix the breakdowns. However, with all the changes and improvements over the years, Krieghoffs are very reliable now. I shot my first trap special at around 130,000 targets in nearly four years with only one broken part, the fore end latch lever and one need to clean it as it was misfiring.
Certainly the most notable improvement would be the ejectors which used to break about every 10-15,000 rounds, at least in my experience. My Trap Special never broke even one. Many improvements can be made that aren't visable to even gunsmiths. Small changes in part fit up dimensions and in heat treat and hardness specs that can make huge differences. Improved tool steel quality is also a factor. All of these add up to make a huge improvement. I believe today that no top trap gun offers better quality then a Krieghoff. Of course they have a great customer service record to go with a great gun. I think one can understand why their popularity has increased so rapidly since the Trap Special was first offered.
The hammers were made a little beefier as well as the trunion in the trigger. The sear springs have been changed to a better coil system. Other than that why mess with perfection ? All K-80 receivers are sold prior to shipment to the states . Jeff