GTA

All Springer/NP/PCP Air Gun Discussion General => PCP/CO2/HPA Air Gun Gates "The Darkside" => Topic started by: parkerd on February 07, 2012, 01:03:18 PM

Title: QB78 Question!
Post by: parkerd on February 07, 2012, 01:03:18 PM
I don't know if this is the right place to put this but this gun is CO2 so I think it make's sense!  :P Anyway's could you take the QB78 with the .22 barrel and install a .25 barrel!? I wan't a bigger/heavier pellet... If I can do this I will go with the QB79 so I have a lil more FPS.. I'm still very much a novice when it come's to modding airguns. So if you could explain it into terms a idiot can understand! "Air rifle modding for dummies!"  ;) Hope ya'll can help!



                                               -Parker
Title: Re: QB78 Question!
Post by: SAADE on February 07, 2012, 01:10:15 PM
In theory yes, you will need to find a .25 cal barrel with the right O.D. (15mm I think) and you will also need to machine/mill the breech end of the barrel to accept the QB o-rings and to mimic the breech shape where the pellet/bolt probe goes in. All precision machine work, not complex, but precise. And... there is a gas transfer port that needs drilling into the lower side of the barrel too.

Maybe someone on here has actually done it to a QB?
Title: Re: QB78 Question!
Post by: parkerd on February 07, 2012, 02:18:46 PM
Whoa!  :o I don't have any of that stuff... haha I guess I will just buy a new gun once I get the money for it!  ;D
Title: Re: QB78 Question!
Post by: SAADE on February 07, 2012, 02:21:27 PM
email Mike Mellick at Flyingdragon airguns and ask him about it, he's the pro.
Title: Re: QB78 Question!
Post by: Rescue912 on February 07, 2012, 02:35:20 PM
The machine work is really pretty straightforward. I put a shortened .22 caliber marauder barrel on my QB in about an hour. I am guessing the .25 would be similar. You will have to do something with the breech and bolt too though, the .22 bolt & o-ring isn't going to seal that .25 hole  8)