GTA

PCP - HPA - C02 Gate => QB-7X Gate -W/Co2 & HPA => Topic started by: frank70 on March 21, 2010, 04:02:02 PM

Title: New QB78
Post by: frank70 on March 21, 2010, 04:02:02 PM
Just received my new QB from Archers Friday and I have to say it was a pleasure to do business with them.I opted for the gold service and I'm really glad I did because now I have an understanding of how my rifle is performing.With RWS Super H Points she is a tack driver but I need more power.She had an average muzzle velocity of 531.7 with 13.8 grn pellets.I would like to get at least 125 to 150 more out of her.Any help would be greatly appreciated! :)
Title: RE: New QB78
Post by: Brutuz on March 21, 2010, 08:43:44 PM


The CDT sealkit came with instructions and has been a great help to me tuning my .22 78 (http://../jscripts/tiny_mce/plugins/emotions/images/smiley-cool.gif)





http://www.charliedatuna.com/CO2TuneByCharlie.htm  (http://www.charliedatuna.com/CO2TuneByCharlie.htm)





check my vids, this particular one might be of interest



http://www.youtube.com/Brutuz62#p/u/6/utmw-wIe3V4 (http://www.youtube.com/Brutuz62#p/u/6/utmw-wIe3V4)



Maybe it's best to start with "Take I" so you can see the progress.

Title: RE: New QB78
Post by: frank70 on March 22, 2010, 02:17:26 PM
Thanks for the links.
Does anyone know of any tuning videos?
Title: RE: New QB78
Post by: patton123 on March 22, 2010, 07:15:33 PM
Frank, it's pretty straight forward. Give it a try.
Title: RE: New QB78
Post by: jake on March 28, 2010, 05:12:49 AM
congrats on the new gun! sorry i cant help you on the muzzle velocitity.
Title: RE: New QB78
Post by: frank70 on March 29, 2010, 04:39:36 PM
So far I have opened the barrel port to 5/32 as well as the port and exit on the bolt,polished the the hammer and cocking block,and added the the seal made from ice maker tubing.Just doing these few things have made such a difference that I'm going to wait until cold weather gets here again before doing anything else to it.The shot count fell from around 55 to about 35.
Since doing these mods Ive taken several starlings cowbirds and grackles with it and its doing its job very well.
Title: RE: New QB78
Post by: Brutuz on March 29, 2010, 05:03:29 PM


You're in business with 35 good shots.



An easy way to improve performance is shimming the hammerspring,

Title: RE: New QB78
Post by: frank70 on April 01, 2010, 06:29:18 AM
What kind of improvement will it make and how will it effect shot count?
Title: RE: New QB78
Post by: Brutuz on April 01, 2010, 06:57:42 AM
Accuracy stays perfect, power goes up as mentioned in the CharlieDaTuna tuning guide. Have you read that one?
Title: RE: New QB78
Post by: frank70 on April 01, 2010, 04:16:24 PM
Yeah I've read the guide. About how many fps will I gain?
Title: RE: New QB78
Post by: Brutuz on April 01, 2010, 07:52:25 PM


That's hard to say, depends on the way it performs out of the box, weight of pellets and temperature, can only let you know my numbers.

Unmodded av. 10 shots 476 fps @ 62F 14.35 grain (one full and one empty powerlet)



Modded first shot 736 fps @ 72F 12.65 grain



Modded av. 10 shots 688 fps @ 68F 14.35 grain

Title: RE: New QB78
Post by: jake on April 08, 2010, 02:31:49 PM
congrats on the new gun!