Ive actually owned this airgun since 2011 or 12, but never really posted about it. I went and looked at Archers site, and it dosent appear that they offer them any more....or i couldnt find them.
I suppose with the influx of multi shot pcps (and accessories) at a reasonable cost, the draw for a repeating co2 gun at the same cost has waned.
I needed the scope off this guy for another project, and only after spending a couple days looking at airguns online, decided I should get it shooting again and see if I really WANT another air rifle.
I tore it down and gave it, its first rebuild and cleaning since i did its original power tune. I did some chrono work before and after, but only recorded the results on a single string.
Anyway before the rebuild 10 shot string (with co2 thats been in it for a few months) ran 630-650, then back down over a magazine with the last shot locking the valve open and dumping the last of the gas.
While i had it apart i polished some machine marks from the valve, that were left from the porting I did years ago.
This is actually the second valve i have for this gun, the original i ported, and modded heavily, and used a steel transfer port on. It was also gutted of the piercer and ran onky on bulk Co2, or compressed air from a remote line.
That valve would deliver CPs at 830fps from bulk or 800psi HPA. JSB Monster (had to go look em up 25.3gr) would hit 630fps, and produce something like 20+ftlbs of energy. I cant remember whwt the 15.9 jsbs did, but it was in the high 700s.
Down side to all that is with the tapered valve seat and cup seal, low spring pressure, it leaked slowly down the barrel. The bulk fill was also a pain in the butt, as was lugging the 68/4500 psi air tank around.
Thus i replaced the valve with a lightly ported and moded stock valve, and kept the piercing assembly.
The transfer port is now poly macro line for ease of replcement, and rhe valve exhaust is flat topped as is the upper receivers port.
during the original power rune i upped hammer spring weight, ported the barrel and polished all the internals as well.
After the valve change i reduced the hammer spring weight to give a flatter shot string with the paired 12gs.
The barrels shrouded and i tried to set the whole thing up to look like an l96...it came out meh, but it fits and shoots well.
Ive always enjoyed this gun, and ive gotten my moneys worth and then some. For someone interested in a low cost, easy, bolt gun trainer, the QBs are still a very good option. Tho im considering trying thr xisico 160 from flying dragon. Im also consider the XS-25 as its been a long time since inhad a springer.
Anyway just remembered how much i liked this gun and wanted to share.
yeah theres two scope rings attached to thst scope. Its off my SILs .270 and will be going back on soon as i get another scope installed.
full 10 shot mag at 22yds we
pre-rebuild
post rebuild end of my sight in string.
I suppose with the influx of multi shot pcps (and accessories) at a reasonable cost, the draw for a repeating co2 gun at the same cost has waned.
I needed the scope off this guy for another project, and only after spending a couple days looking at airguns online, decided I should get it shooting again and see if I really WANT another air rifle.
I tore it down and gave it, its first rebuild and cleaning since i did its original power tune. I did some chrono work before and after, but only recorded the results on a single string.
Anyway before the rebuild 10 shot string (with co2 thats been in it for a few months) ran 630-650, then back down over a magazine with the last shot locking the valve open and dumping the last of the gas.
While i had it apart i polished some machine marks from the valve, that were left from the porting I did years ago.
This is actually the second valve i have for this gun, the original i ported, and modded heavily, and used a steel transfer port on. It was also gutted of the piercer and ran onky on bulk Co2, or compressed air from a remote line.
That valve would deliver CPs at 830fps from bulk or 800psi HPA. JSB Monster (had to go look em up 25.3gr) would hit 630fps, and produce something like 20+ftlbs of energy. I cant remember whwt the 15.9 jsbs did, but it was in the high 700s.
Down side to all that is with the tapered valve seat and cup seal, low spring pressure, it leaked slowly down the barrel. The bulk fill was also a pain in the butt, as was lugging the 68/4500 psi air tank around.
Thus i replaced the valve with a lightly ported and moded stock valve, and kept the piercing assembly.
The transfer port is now poly macro line for ease of replcement, and rhe valve exhaust is flat topped as is the upper receivers port.
during the original power rune i upped hammer spring weight, ported the barrel and polished all the internals as well.
After the valve change i reduced the hammer spring weight to give a flatter shot string with the paired 12gs.
The barrels shrouded and i tried to set the whole thing up to look like an l96...it came out meh, but it fits and shoots well.
Ive always enjoyed this gun, and ive gotten my moneys worth and then some. For someone interested in a low cost, easy, bolt gun trainer, the QBs are still a very good option. Tho im considering trying thr xisico 160 from flying dragon. Im also consider the XS-25 as its been a long time since inhad a springer.
Anyway just remembered how much i liked this gun and wanted to share.
yeah theres two scope rings attached to thst scope. Its off my SILs .270 and will be going back on soon as i get another scope installed.
full 10 shot mag at 22yds we
pre-rebuild
post rebuild end of my sight in string.
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Is the barrel shroud home made or commercial? I don't remember seeing a QB78 like yours. Did not know there is a repeater model. I have a basic .22 QB78 in original wood stock and factory barrel, I tuned it myself as well and got around 680 fps like yours. It has been sitting there for over 6 yrs, I just shoot my springers instead of messing with CO2. I bought a bulk charge adapter and shoot charged Co2. It is only good for 20 or so shots and start to drop fps if I recall. Rather loud.
