...string, but no curve. Good news is the nose-dive holds off for 13 or so shots...

Outdoors, 15 C. 3000 PSI on the 20-78 with the 3K tube.
I put the max flow valve back into the tube. I also made a spring guide for the stem return spring. I removed all the hammer spring pre-load, with just the stock spring in the gun.
Shot with the 18.1 gr JSB Exact heavy:

1.) 743.7
2.) 747.7
3.) 746.8
4.) 740.3
5.) 742.7
6.) 735.7
7.) 738.1
8.) 746.8
9.) 744.8
10.) 739.8
11.) 735.7
12.) 731.6
13.) 722.4
14.) 722.1
15.) 713.0
16.) 704.6

Going by the gauge on the hill pump, that string used about 1400 PSI.

I have mixed feelings about this. Frankly, I was hoping for a bit more usable velocity.

Is continually subjecting the gun to 3K PSI going to be a concern?

I'm going to leave things as they are for a while.
It looks like I'm going to have to go for a regulated bottle set-up. I may end up putting the .177 bbl on the 3K tube at a later date...

Had a pretty good day out there. The off & on rain kind of put a damper on the use of the hill pump. I would have shot the 20-78 a lot more if the weather had been better. Always have a back-up 13-XX pumper a long, so the day did have it's merits. A few pix if anyone's interested...

Regards,

Doc Sharptail