If anyone has these flying well out of a smooth twist x what’s the speed you’ve had the best success with them? My gun likes to shoot em at 851fps (extreme spread 8, SD 2). But they don’t like that speed. Getting 2” groups at 50. Was getting half inch at 50 with the 45s, so I know it’s capable of better. I know every gun is different. What velocity works for YOU!?
JSB 50.15s optimum speed in x barrel?
- Thread starter DrOcean
- Start date
I went through that testing last year in preps for EBR. However, my gun is an ST barrel, not an STX barrel in a .30 FX Bobcat Mk2. What I found was that at 52 yards, both the 44.75 grain and the 50.1 grain were almost identical in accuracy. I finally decided to use the 44.75 grain pellets since they were slightly more consistent at 75 and 100 yards. I may end up using the 50.1 this year due to its significantly higher BC and the swirling winds encountered at the range we use at EBR...I shot the 44.75 grain at 885 FPS, and the 50.1 grain at 850 FPS.
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Nice. Mine came shooting the 45s hole in hole at 50yds at about 827fps. I will be hunting a lot and needed more, so I tuned it up n started with the 50s. I found a couple tunes that the gun loved, but not the pellets. Gun was slinging em very consistently but they were not stable anywhere from 790-890fps. Turned the reg down again n started over. Hit another sweet spot for the gun right at (according to the fx manometer) 150bar. Hammer spring tuned all the way to max n valve stop waaay open. Extreme spread 6 with a SD of 1 in 14 shots. Next 14 ES of 6 with an SD or 2. So super consistent. 853fps avg. pellets one ragged hole at 50. 853 awesome 849 not lol. I even tried like 865fps, moved hammer to 5 for 855fps, then tweaked valve stop to avg about 850fps. Same velocity basically but the gun hates it. ES like 25 with SD of like 12. She wants to be wide open.
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I’m going to try to get her on paper at 100yds tomorrow. If she groups well there I’m a quit poking at it for a while n start hunting.
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I've shot the 50.15 as fast as 960 but usually average 950 at 170 bar. Around 1/2" groups at 60 yards but I'm not that good a shot anymore with poor vision and my pulse wiggling the crosshairs. I can get about 3/8" groups shooting off a leadsled rest but who hunts off of one. I did some light porting, installed a 5.8mm valve seat, hammer weight and Huma regulator to get the speed.
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Approximately how many shots per fill do you get there? Like 14-18? With my current tune I get 3 mags (42 shots) as all usable shots out to 50yds. At 100 yds it would seem that I get 2.5 mags or about 35 shots. The last several shots fall a few inches low at 100. Not sure why. They APPEAR to be still on the reg. I gots to gets better gauges.
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I never really payed attention to the shot count but I know it's at least a 24 shot magazine.
Edit: I told you wrong. I just went out to test and it did 16 shots on the regulator. I must've been tethered last time I shot off the bench.
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Ah. Nice estimate then I suppose! That’s definitely too few shots for me with this gun. Think I’ll venture into something significantly larger eventually so I can get high enough fpe to legally deer hunt here (probably something smaller too...) such as a 45 texan or a hammer and a 22 dreamline or vulcan.
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