I bought this R7 3 or 4 years ago and thought it shot quite well, although power was on the low side. I took it out recently and did some more shooting across a chrono and the results were dismal. Different weight pellets kinda shot the same-somewhat less than 600 fps. I've been avoiding the teardown of this but decided it was time. I disassembled the rifle and found that the innards were really crappy. The lubricant used on the spring etc was this black, gritty shtuff that looked like it came from one of Hitler's WWII tanks. The spring also had a bit of a curve to it as well and the piston seal was covered with it. Weihrauch should be ashamed of themselves for assembling their guns this way. I bought a Vortek PG4 Delrin tune kit and installed it after cleaning all the gunk inside. The only deviation I made was to coat the piston and seal with moly paste instead of the red grease that comes with the kit. I used that stuff on the spring only. I followed the procedure on the YouTube video made by TbT. It's well worth watching even though you may not buy a Tinbum kit. After installation, I shot it about 20 times and then did more testing on the chrono. Before tuning, it shot JSB 7.87 pellets at 598 fps and after was 684 with a whopping increase of just over 2 fpe. I also shot 7.33, 8.4, 10.3 and 13.4 gr pellets, but the 7.87 was the clear winner. This really made me feel so much better about this rifle, and truly it will be an heirloom in my family. BTW, it has a Corcoran stock on it and a 4-16 Sightron S-Tac scope.
