Yeah, that's a good looking tune you have there! As to the effectiveness on squirrel, for brain shots I would say that is about twice as much energy as you need at modest ranges (say, out to 35 yards). Or about right for vitals shots...I would expect a pass through and two holes is more effective than one for such shots.Case in point, I built a regulated QB78 for a buddy a few weeks back that was set to shoot JSB 18.1gr at about 29fpe. A friend at work invited me over to thin out the squirrels in his back yard one Saturday. In this suburban setting, the longest shot would be about 30 - 35 yards so on the night before, I dialed back the rifle to 15fpe and re-zeroed. The following morning, dispatched 6 in a row:http://www.gatewaytoairguns.org/GTA/index.php?topic=78577
How did you tune your disco?
Quote from: Rimshot on February 02, 2015, 09:40:54 PMHow did you tune your disco?My tunings:Three screw modPolished leadeLapped barrelCut three full coils from stock hammer springHammered the "nail" part out of a pop rivet and used the other part as the spring guideA standard 1.5" 10-32 screw for power adjuster (will bling out later)Oddly enough, I stumbled on this tune. With all the power adjuster parts above, I reassembled, turned the PA screw until the gun wouldn't cock, then backed it out to one half turn less than max...Strangely, I thought that max point was "coil bind" on the spring. What was actually happening was the pop rivet was very long, and was keeping the hammer from fully cocking I intended for the coil being maxed as in what most people do, and thought that was happening until I shot over the chrony and only got 685 fps. I knew something was wrong because a different spring guide with the same cut spring got me 780 fps with the same pellets. But the pop river was the exact length to restrict the hammer to this tune velocity. Strange how sometimes the best discoveries (no pun) are accidents...
Quote from: tjcib on February 03, 2015, 06:33:03 PMQuote from: Rimshot on February 02, 2015, 09:40:54 PMHow did you tune your disco?My tunings:Three screw modPolished leadeLapped barrelCut three full coils from stock hammer springHammered the "nail" part out of a pop rivet and used the other part as the spring guideA standard 1.5" 10-32 screw for power adjuster (will bling out later)Oddly enough, I stumbled on this tune. With all the power adjuster parts above, I reassembled, turned the PA screw until the gun wouldn't cock, then backed it out to one half turn less than max...Strangely, I thought that max point was "coil bind" on the spring. What was actually happening was the pop rivet was very long, and was keeping the hammer from fully cocking I intended for the coil being maxed as in what most people do, and thought that was happening until I shot over the chrony and only got 685 fps. I knew something was wrong because a different spring guide with the same cut spring got me 780 fps with the same pellets. But the pop river was the exact length to restrict the hammer to this tune velocity. Strange how sometimes the best discoveries (no pun) are accidents...Post is getting old but.... what's the length of your spring guide (rivet)?
Nice. What's your address? I need you to tune my disco!
I am going to cut down my hammer spring on my Disco as well, as it stands Im only getting 12-14 shots from 2000psi down to 1000psi. Any suggestions on how many coils to cut off? I was thinking of starting with 1.5 coils and see if I can get a decent tune with the 10-32 screw PA. If I can get anywhere close to this with mine I'll be a happy camper, the more useable shots the better