Tech Sight for Remington 597. I like them much more than the Willams. More robust, Unobtrusive and the 0.062 diopter is a happy middle ground for general use for me.
www.tech-sights.com 
Better groupings than I get with a scoped 2289 at 25 yards.Good shooting and glad you worked out the issue. I may have missed it but what was the issue you started having and what was the fix? Number of rounds or age when the issue developed? I ask because the HW30 is also my favorite model and most frequently shot.
The Grey laminate gun that I was originally having low power issues is from 2017 or 18. The shot count is in the tens of thousands. It has a Vortek PG2 kit in it. It's been through a couple springs and piston seals. My issue with it was the power was lower than normal. The piston seal was worn so I replaced it with a seal I thought was new and there was no improvement. I tried a fresh spring and there was no improvement. Out of usual suspects I swapped the kit and piston with my other HW30 to see if the compression tube somehow was bad. The low power followed the kit and piston to my peep sighted 30. I replaced what looked and tested like a good piston seal and the power was magically restored. The accuracy improved as well. I can't explain what was wrong with that seal. All I know is that it was bad. The gun is shooting almost 8.5 fpe now. That's about what I expect with a fresh seal and spring.
They don't last forever. It was my fault for reusing a seal of unknown history. It's possible that it was used in a tighter gun making it undersized in these. It definitely had a looser fit than I'm used to. All I know is the "magic sizing" has always worked for me. I'm just a knuckle head for reusing a seal from a different gun. Just goes to show you sometimes you can't see a seal's bad.
