Swop the hammer spring to a 1.2mm diameter wire...factory spring is 1.4mm.Remove all the grease from the hammer and tube.If shooting JSB 18 gr pellets cut the lighter spring until Velocity is 900fps at 190bar. Shoot over a crony... Velocity will steadily increase forming a bell curve. Now use the power wheel to flatten the bell curve at say 930 fps... Should give an easy 60 to 70 shots within 3%.
I’ve figured out the pressure sweet spot for all my Sumatras and when it’s shooting at the top of the curve it’s just automatic. This past weekend shooting standing with a Caldwell Magnum fieldpod at 100 yards I was able to do a 5 shot group with all the pellets touching. And I'm not a paper puncher by any stretch. It’s a shame that with 500cc of air you can only get about 18 great shots per fill. Someone please make a regulator for this gun.
Quote from: Froggy. on September 11, 2015, 03:56:58 AMSwop the hammer spring to a 1.2mm diameter wire...factory spring is 1.4mm.Remove all the grease from the hammer and tube.If shooting JSB 18 gr pellets cut the lighter spring until Velocity is 900fps at 190bar. Shoot over a crony... Velocity will steadily increase forming a bell curve. Now use the power wheel to flatten the bell curve at say 930 fps... Should give an easy 60 to 70 shots within 3%.Thanks. I also want to get my 25 cal shooting more efficient. I hope I can find metric sized springs.
Just for mine & other's FYI, who is Nick? Thanks.
Norm I spoke with Nick and he said that they can make a regulator for it but he needs the rifle...if any one wants a free regulator send your rifle to Nick and he will send it back regulated for free. But they need the rifle for fit and testing.