Dervburner 2,548 Posted September 3, 2020 Report Share Posted September 3, 2020 Well, I’ve been having a bit of a play with the impact to try and find a good useful power range on the dial and air flow valve, without needing to alter either the reg pressure or the hammer spring tension. At the moment its on 95 bar reg pressure. I’d appreciate any feedback from the FAC air lads on here, who know more about this than I do, regarding my current set up. First, using jsb 16 grain exact on minimum setting on the power wheel, and air flow on the first line they’re doing 737fps (19.3 ft lb). Air flow on line 2 they’re at 778fps (21.5 ft lb) and on line 4 they’re doing 811fps (22.46 ft lb). Leaving the air flow on line 4 I tried the 16 grain again at power level 3, this gave 913fps (29.62 ft lb) and on power level 4 978fps (33.99 ft lb). This was as high as I wanted to go with 16 grain pellets, so I moved over to the jsb 18.1 grain with the air flow on line 4. Adjustment by the power wheel only gave me these readings. P Min-741fps (22.07 ft lb) P1-763fps (23.40 ft lb) P2-813fps (26.57 ft lb) P3-876fps (30.84 ft lb) P4-924fps (34.32 ft lb) P5-952fps (36.43 ft lb) and P max-981fps (38.68 ft lb). H&N 21 grain slugs on max setting gave 931fps (40.42 ft lb). Obviously I still need to do accuracy tests at all levels. Any suggestions regarding these figures, and if they are good settings for this calibre would be appreciated as I have little experience with these set ups . Quote Link to post
villaman 9,979 Posted September 3, 2020 Report Share Posted September 3, 2020 About right for the slugs , that about what I am running them at in my crown . Has your impact got the power plenum ? 1 Quote Link to post
Dervburner 2,548 Posted September 3, 2020 Author Report Share Posted September 3, 2020 3 hours ago, villaman said: About right for the slugs , that about what I am running them at in my crown . Has your impact got the power plenum ? Yes vm, it’s got a power plenum and 700mm barrel. Quote Link to post
villaman 9,979 Posted September 3, 2020 Report Share Posted September 3, 2020 If you want higher power then testing at a higher reg pressure will be needed. Like I said, H&N 21 gr slugs I am running @ 930ish , which is perfect and accurate Quote Link to post
villaman 9,979 Posted September 3, 2020 Report Share Posted September 3, 2020 I know a few which are running there impacts .22 @ 120 bar Quote Link to post
Dervburner 2,548 Posted September 3, 2020 Author Report Share Posted September 3, 2020 1 hour ago, villaman said: I know a few which are running there impacts .22 @ 120 bar Ok, thanks. Any idea what power range they’re at VM ? Quote Link to post
villaman 9,979 Posted September 3, 2020 Report Share Posted September 3, 2020 Sorry mate I don’t , what one gun runs at another will be different , trial and error with them 2 Quote Link to post
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