Decided to take a break tonight, and sit and shoot the 20-78 from rest.
JSB Predators @ 12 Meters, 6X on the 4-12X Legend. 5 Shots @ 1800 PSI, which out of this rifle is the mid 7's.
Upping the pressure to 2000 PSI in this gun reduces velocity by almost 100 fps for the front third of the string:
5 shots again, and the reduction in group size becomes apparent here.
I'm not really sure what's happening here. I had noticed similar behaviour with velocity changes in my riflized 13-XX's. From what I've seen, tight groups with the predators are not static to set velocity- going up another extra 100 fps seems to tighten groups up again...
Just for general interest:
Two views of a recovered Predator after driving the pull ring tab and it's rivet through a soda can 740-760 fps.
The bottom of the can, I sort of felt sorry for.
What's funny is that this sine wave of group sizes doesn't appear so glaringly with the JSB Exact Heavy, which is a favourite of mine...
Regards,
Doc Sharptail
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