It has been a couple weeks since I announced the mods and tuning of the new TF-59 Chinese Air Rifle by Compasseco. I have to say again that the overall build quality was good. After my initial tune and mods, it was not to my satisfaction. Cocking at the bottom of stroke was a bit tight and velocity was low. I did use the same spring as came with it but changed moded the seal retaining button and of course put a new delrin spring guide in to fit the original spring. Also did the internal delrin sleeve in the piston. Apparently I missed the mark on the calculations of clearance between spring and sleeve, so I tore her down again and re measured and found I was .012 off on the ID of piston. So I made the adjustments on the lathe with boring bar and put her back to gether. I have been shooting her for a week now off and on. probably about 500 pellets or so.
Now she cocks perfect and the fps is up almost 80 fps. I ran out of Gamo Hunters but did manage to chrony her using RWS Superdomw. She is spiting out lead on an average of 700 fps with less than a 12 fps variable. That should improve after another tin or two of pellets.
So I finally got serious about checking for accuracy. I set up a few targets and run some JSP's, CP's light and heavy. Beeman FTS, Gamo wadcutters, then ended up with the RWS Superdomes. I also found in the process that I have aBSA Scope which is not holding the poi and switched over to a new Bushnell 4-16X40 AO Trophy. So below is what I ended up shooting after re sighting the Bushnell. Each target got 5 shots at 28 yards. The target was sized for 30 yards but I like them BIG..
I had put a riser on the TF-59 when I was using the BSA 3-12X50 AO MilDot, but not needed when I changed over to the Bushnell Scope. The pad works great if you have a low comb and big scope.
