Anyone have a BC for the jsb king mkll heavies .25? My gun (FX BC mk1) shoots them averaged at 805 FPS at muzzle. I am done on chono tests now going to start the 50y accuracy compaired with the regular kings.
BC for MKll JSB heavies.
- Thread starter Monkyshine
- Start date
I believe the ST barrels have been producing around .043 or in that vicinity. Non ST barrels seem to producing BC'S much nearer to .05.
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I need to go study on BC and acquiring a good number for my rifle. My groups are better with heavies at the 50y tests. Will turn up gun to 900 tomorrow.
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I know some rifles are shooting these very good from high 700's and others to high 800's and everywhere inbetween . I haven't heard of any other numbers. I'm curious about these shooting 900- 1000 fps. My wildcat shoots these at 825 fps pretty accurately. I'm waiting for my new chrono to do a bit more experimenting with these pellets.
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What kind of groups are you getting at 825 fps and at how far ?? I have some on order and am going to try them in my bobcat .25 Just wondering what to expect if my bobcat is shooting 25.4 's at 935-940 fps es=9 sd=2 ???
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They average around 80 to 100 fps slower than the 25 kings depending if you lube your pellets or not. My best group with these was 1/2 inch at 65 yards. Perfect conditions though. Lately its been cold and windy here in CT. These heavies are more consistently accurate than the 25.4 kings at 50+ yards in my wildcat. It looks like you'll be shooting these around 840-860 fps which should be very good. My hammer spring is maxed out. I wish I could shoot them at the velocity of your bobcat. Im not gonna mess with my reg. yet . Im gonna bring the velocity down a little and shoot some groups. I need my new chrono. It seems like every barrel shoots these lights out at different velocities, I guess like all other pellets. You just have to do your own testing. Good luck. Let us know how you make out
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I had my hammer spring maxed out and then backed it off about 1.75 turns , my fps went up and it got more consistant, my bobcat is regulated ... You may be able to try that on your wildcat ... IDK When I received it from aoa it was shooting 860-875 on 25.4's I haven't messed with the reg .
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A few years ago I contacted JSB as various sources quoted different BC values. JSB's reply was along the lines of - there are so many variables they don't quote a BC for their pellets. We went on to discuss the most influential parameters that affect BC.
Subsequently (and maybe incorrectly) I have taken average fps values at two different ranges and used that to calculate the average BC of those pellets, with that gun, at that fps, in those atmospheric conditions (wind speed, temperature, pressure).
Subsequently (and maybe incorrectly) I have taken average fps values at two different ranges and used that to calculate the average BC of those pellets, with that gun, at that fps, in those atmospheric conditions (wind speed, temperature, pressure).
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