I've seen some people go back and reduce the port opening for low power configuration, and increase it back for high power - using types of valves that allow that type of opening and closing.
He has since backed down to 240 fpe
Quote from: rkr on February 24, 2014, 07:01:14 AMHe has since backed down to 240 fpeThat's around the tuning-limit of the Fire 201/202/Recluse Shin Sung/Sam Yang 9mms too.Good thing he backed it down, so he doesn't hit the space telescope with that thing.I wonder what bullet he's shooting at 240 FPE. It must be doing some serious speed.
Another one:200 bar, 88 grain bullets, 2 shims for inner spring, one coil off the outer spring880fps885fps889fps886fps875fps150 barThat's 14 fps spread and estimated 1/2" vertical POI shift at 100M at 154 fpe. I think that's good enough for some longer range testing.
Quote from: rkr on April 15, 2014, 11:31:04 AMAnother one:200 bar, 88 grain bullets, 2 shims for inner spring, one coil off the outer spring880fps885fps889fps886fps875fps150 barThat's 14 fps spread and estimated 1/2" vertical POI shift at 100M at 154 fpe. I think that's good enough for some longer range testing.You have to be happy those strings! Are you using chairgun and if so what is the BC for the 88gn bullet? The reason I ask, Chargun shows my 30 cal will a 1.6" drop from 870-830 fps with a 70gn and a BC of .16 at 100 yards. Actual shooting indicates ~.8". Chair gun seems to be off by a factor of 2.Tom
That one, is not going to bend, lol