Those of you worried about the barrel bands used on QB’s, this might be an alternative. Had an old spare QB 78D metal barrel band and an old QB78 standard barrel to try it on.
Cut two o-ring seats just ahead and just behind the cross slot for the barrel band screw. Want the band to completely hide the cuts.
Slightly widen the cross cut for the barrel band screw if it binds Want it to have a slight bit of in and out play.
Will have to control the depth. There is plenty of beef in the barrel, but want the 0-rings to end up a snug fit. Used a pair of spare barrel breech o-rings (just stretched a bit more to fit over the barrel).
A slight bevel on the inside edge of the metal barrel band and a touch of silicon grease helps to get the band to snugly slide over the o-rings. A bit of polish on the inside of the barrel band’s upper loop helps.
If I try, can get the barrel to slide front to rear with no side to side or up and down play when the barrel breech lock screw is removed. With the screw tight, there’s no motion. Seems to be no band to barrel contact at all, the band holds onto the o-rings which hold the barrel centered in the barrel band.
Perhaps this will let the gas tube expand and contract a little bit without binding on that barrel band (not that I really had a problem with that, but evidently some QB owners either have a problem, or think they have a problem).
Testing:
66 degrees isn’t the best co2 weather for long shot counts, and this rifle was set up to run at 600 fps @ 85 degrees. At 66 degrees it was running at 560 fps AND using a bit more gas than expected (part of that was gun cooling from shooting too quickly).
Windy, and I tired to judge the wind as best I could at the 25 yard test targets, but evidently I failed quite often.
[
If the new barrel band system helped, can’t tell it. Didn’t hurt, and maybe it will be worth the effort when summer comes here and the temperature difference is greater. As it stands mow, it’s stable, but no more or less accurate than I’d expect for that rifle. Considering the less than $80 cost of the rifle and that those are consecutive shots with no “do-oversâ€, it’s really not bad at all.
-----
that rifle is using a much lightened hammer. One of the odd things about light weight hammers is that they tend to keep shooting well until the gas pressure is “way lowâ€. heavy haqmmers tend to a more gradual decline in speed, the light hammer tends to shoot slowly “all of a suddenâ€.
