GTA
PCP - HPA - C02 Gate => QB-7X Gate -W/Co2 & HPA => : JTK January 29, 2008, 10:38:11 PM
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Got my 79 yesterday. shot it at the painball shop when I went to get a 9 ounce CO2 canister.. Only registered about 380fps on his crony ??? It is a .177 cal and I was expecting at least in the 500-600 range. Strip cleaned the barrel and she seems bit better but havent had the chance to chrony again. btw barrel was very dirty. What would be the 1st place to look? Shee seems to like jsb and stacks them in one hole on 10m.
btw.. if I look at the pix on the net then my bolt probe looks like a .22cal as it is hollow. or does the images suggest that I cut off the hollow and glue on a probe?
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think you're going to like that rifle a whole lot.
As for speed, the #1 strangle point is the transfer port seal. Just a little do-nut of soft plastic that fits between the barrel and the gas tube, but it's often mangled and squished nearly closed. Just changing that to a polly-seal (made from ice maker tubing) should get your vel. up to where you expected.
the following is a tune guide. You certainly don't have to do all of it, but read it anyway..esp. the transfer port parts.
http://www.gatewaytoairguns.com/library/Charlie’s%20QB-78%20Tune.htm
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Yep...they come clogged with what looks like old ear wax. It's a long slow boat from China (litterally) and they are well preserved from the salt air. When you do the transfer port seal, will have the barrel off the rifle...which is a good time to do a good cleaning.
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thanks ribbonstone, yes already love the rifle. have read cdt's tuen and also co2tune's was just not sure as I did not have the qb when I studdied up on it :) will rip her appart next week I think!
JT
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If you do nothing else, then smooth the indise of the tube and change the trasfer port seal. that should get you at least up to factory reported specs.
Will probably tear up some of the o-rings in getting it apart the first time, so I'd order a reseal kit. Once you smooth the rough edges, won't tear up o-rings putting it back together. Just get it clean-clean befores reassembly, nothing ttears up valve seals as quickly as drit/dirt.
Yeah...has become my favorite of the QB's. Can run it from a remote, from a 9oz., from a 3.5oz., (from the old style 7oz. too if you can find one), and can get a 12gr. adaptor if you happen to have some of those laying around.
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I've got one of those too. Now it just needs one of those multi shot magazines to make better use of the paintball tank.