QB35. 35 caliber QB78 HPA conversion.

[thammer]

It has picked up a little power as it has broken in. A little fine tuning is still needed. A little more starting pressure and a smidge less hammer spring should get a nice 5 shot bell curve at 115fpe or 8-10 shots at 100fpe. Takes less than 75 pumps to re-fill with a Benjamin hand pump. 

 

[Grumpytroll]

Can you give more info on the modification on this qb to make an qb35 very interested.
Thanks
Grumpy

 

[thammer]

"Grumpytroll"Can you give more info on the modification on this qb to make an qb35 very interested.
Thanks
Grumpy

I machined a 35 cal barrel that was 28" long to fit the stock breech. And made a sleeve to go over the stock probe to seal the barrel. I had a 30" HPA tube threaded for and end cap and all the holes and slots cut. I drilled and tapped the valve to allow (3) 10-32 high tensil screws to pin it in place at high pressure. I put my Deadblow valve system in the stock valve along with a few more modifications including a 1/4" Transfer port and spacers to add preload to the hammer.