Finally getting around to taming my RAW HM1000x Chassis rifle. Out of the box it was pushing JSB 34 grain King Heavy pellets at 910~920 fps which I considered to be a little fast. At 30 yards it was almost hole-in hole but the 50 yard spread was unacceptable - more like an inch to an inch-and-a half. Switched to FX 34 grain pellets (same thing really) and made minor adjustments to the reg and hammer spring and got it down to 890 fps average with an ES of 5 and an SD of 1.7, finally resulting in a 10 shot .1875" center-to-center group or .3581 MOA at 50 yards. When I say minor adjustments I do mean MINOR adjustments! As Steve Scialli says, small adjustments can make a big difference! I'm glad I'm retired and have lots of time (and pellets!) to experiment, test, correct and hopefully improve! This seems to be a very stable platform so I expect it to hold tight groups going forward. If I have a chance to shoot at 100 yards I'll update this post with the results.
