Before and After on my QB Tune

[Fisherdude]

This past January, I purchased a QB78 from ^&$@_=s.  I haven't been satasfied with the accuracy, so I went to work on it.  
* Replaced .177 barrel with a .22 barrel
* Re-cut and polish crown
* Opened up gas passages for more CO2 to increase velocity per instructions on CDT web site
* Pinned the end of the bolt (Facrory bolt pushes on the skirt to seat pellet - I didn't like that plan)
* Polished the loading ramp
* Put in a second set screw to help hold the barrel
* Replaced the o-rings on the bolt and barrel
* Polished the hammer
* 3 washers behind the hammer spring
* I did not remove or modify the valve

Before I did all this, I was getting pretty crappy groups - about 2 inches at 20 yards. The rifle was shooting at 500 fps with .22 CPHPs and JSB Exacts.  After the tune, it is shooting 690 -700 fps with the same pellets.  Plus the accuracy is now to my liking.  Now I have enough fpe for hunting and the accuracy to comfortably take a squirrell at 30 -40 yards.  The most interesting thing to me was that the accuracy with the CPHPs improved so much.  

[snookman]

 That is a drastic improvement.

 It just shows how a few modifications can turn a so so gun into a KEEPER.

 Great job, snookman

[dk1677]

Nice job!

[Bentong]

That's outstanding job on getting her shoot with tight grouping. On my QB79, I had to go from .22 to .177 and very satisfied it shoots different pellets tightly.

[MichaelM]

nice job!! now to mod the valve for a touch more flow and add a hammer debouncer and your golden!!!

[kp4att]

YOU HAD A SHOTGUN... NOW YOU CREATE AN QB AIR RIFLE.   NICE JOB

/GERALD

[Springer25]

wow. you did a nice job very accurate.

[Jack]

What a difference - congrats big time.

[CDNMatt]

Here is my question for you... have the .22 with a Techforce PCP kit, I do see now a lot of pin at the end of a lot of moded bolts well, 1 how do you preform such mod and what tools/supplies do you need. 2 is there an increased performance?
the washers for the hammer spring what size? whats the difference between this and just adding a crossman spring to this as the PCP kits instructs me to. Now Living in Canada we need our F.A.C. if out rifles shoot over 500fps and have more than 12flb of force... lol well i just registered this rifle. guess the Canadian government is afraid of someone robbing a bank with an air rifle lol twang hold on gota reload dont move it will take me 10 sec lol.. now that my rifle is regestered has anyone drilled out there bolt and the tiny hole buy the recever to allow more airflow?
That's my last question!!!!
Cheers