 |  | | | |  | |  |  | Troublesome QB78DL Fixed! |  | |  |  | |
 Posted: Fri Nov 09, 2012 4:05 pm |
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| radar |
| Silver Status Member |
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| Joined: 13 Nov 2011 |
| Posts: 1138 |
| Location: Des Moines, Iowa, USA |
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Stock QB78 Deluxe, only mod was Archer power tune kit. Long story short, bore lapped, recrowned, still got wild flyers about 1 in 5 or 6 shots. Recently it started doing a 10 MOA shift to the right at the middle 10 shots or so. (out of 30-ish useable shots).
I took off the barrel band on suggestion from walrus over at the UK Chinese Airgun Forum where I sometimes hang out.
Fixed it. The pellet pickiness is gone (It never shot my beloved JSB Exacts well, and now they're the best in it.) The POI shift is gone. The wild flyers, which lapping helped but did not totally eliminate, are gone.
It averages 1" 5-shot groups at 30 meters now.
Gotta love it! |
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It's never too late to have a happy childhood. |
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| Posted: Sat Nov 10, 2012 5:38 am |
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| Alstone |
| Moderator & Site Supporter |
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| Joined: 01 Mar 2007 |
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| Location: Linconshire, ENGLAND |
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I had the same type of problem with the barrel on my QB78, it changed poi slowly during a shoot, and the next time I used it the poi was back on target.
I them used the barrel on my SA80 with no barrel band and it shoots the best it ever has, I have use two barrel retaining screws to make up for the missing band.
Al |
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| Posted: Sat Nov 10, 2012 9:10 am |
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| radar |
| Silver Status Member |
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| Joined: 13 Nov 2011 |
| Posts: 1138 |
| Location: Des Moines, Iowa, USA |
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That's a good idea, I think. I will tap another screw in the breech area. Thank's for that!
Rob |
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It's never too late to have a happy childhood. |
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