Decided to try and stablize the barrel so the groups would stay more or less at point of aim from day-to-day, also hoped that might make an accuracy difference.
That’s the main point of the Discovery design (as well as the 2260) that really seems 2nd rate. The breech is held on by a large screw in the back, a dinky little screw less than 2†ahead of that back screw, leaving 24†of barrel and about m1†of breech just wiggling however it wants to wiggle. Over tightening that dinky screw is not recommended.
Have noticed that on the match version of the Disco., there is a barrel band right ahead of the breech, which should add some stability and is worth looking into as a modification for a standard Discovery.
Rifle was bought used and already had two barrel bands, one of which was drilled for 4 screws (two to angle down and bear on the gas tube, two angled up for the barrel. I swapped the two around, putting the one with the angled screws just ahead of the fore end.
(Click to enlarge the pictures)
The standard barrel band was put towards the muzzle. BEHIND the band, a shart section of a 1377 plastic spacer was glued to the bottom of the barrel. It is not glued to the gas tube, just to the barrel, and is under slight tension when the front band is in place.
(BTW: put it behind the barrel band, as you need to slide the barrel band forward to get it and the breech off when disassembling.)
So the finished rifle looks like this:
And the test groups from today look like this:
the first 3 groups (top to bottom on the left) were for adjusting the scope; really didn't change it's point of impact all that much considering I had the whole top end and the scope off between sight ins.
The best pellets didn’t really get any better, but at least now there are at least 3 pellets that shoot well enough to keep me happy. Are some new JSB’s on the way (light and heavy) that will also get a try out.... it didn't like my 18gr. JSB's a bit. But you gotta like that freak 5-shot .07" 20 yard group.
Have modded this rifle with a weaker striker spring, guide, and a lightened hammer in order to bring it down to the 16 – 17 foot pound area (depending on the pellet used). This gives between 40 and 45 shots in a sweet spot between 1800PSI and 1100psi that have a +/- 10fps variation.
The neat thing is that I can fill to 1800psi, shoot 40 shots, and it takes 40 pumps of a hand pump to bring it back up to 1800psi.
