GTA
All Springer/NP/PCP Air Gun Discussion General => PCP/CO2/HPA Air Gun Gates "The Darkside" => Topic started by: bnt55 on March 31, 2018, 03:31:28 PM
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Installed tune kit from Jefferson State Air Rifles on my Gauntlet, the regulator is set to 1250 psi and I am shooting 14.3 CHPD. The first couple of shots I was adjusting hammer spring load to get to 820 fps, but I noticed in the middle of the string the fps went up into the 850's then back down? I do think I have a very slight leak at the new poppet which I will be addressing this coming week.
My goal is accuracy and shot count. I will be hunting starlings at around 45 yards and would really like to use my JSB 18.13 pellets since they are so accurate. Any tips would be greatly appreciated
Description: umarex gauntlet after JSAR tune
Notes 1: Crosman 14.3
Notes 2: Regulator set to 1250 psi
Distance to Chrono (FT): 0.00
Ballistic Coefficient: 1.000
Bullet Weight (gr): 14.300
Altitude (FT): 0.0
Temp: 66 °F
BP: 30.06 inHG
Shots
# FPS FT-LBS PF
88 799 20.27 11.43
87 802 20.43 11.47
86 806 20.63 11.53
85 812 20.94 11.61
84 822 21.46 11.75
83 828 21.77 11.84
82 828 21.77 11.84
81 836 22.20 11.95
80 839 22.36 12.00
79 841 22.46 12.03
78 846 22.73 12.10
77 851 23.00 12.17
76 855 23.22 12.23
75 855 23.22 12.23
74 855 23.22 12.23
73 853 23.11 12.20
72 854 23.16 12.21
71 852 23.05 12.18
70 855 23.22 12.23
69 853 23.11 12.20
68 846 22.73 12.10
67 849 22.89 12.14
66 840 22.41 12.01
65 833 22.04 11.91
64 833 22.04 11.91
63 833 22.04 11.91
62 833 22.04 11.91
61 832 21.98 11.90
60 826 21.67 11.81
59 829 21.83 11.85
58 833 22.04 11.91
57 829 21.83 11.85
56 826 21.67 11.81
55 825 21.62 11.80
54 823 21.51 11.77
53 828 21.77 11.84
52 824 21.56 11.78
51 825 21.62 11.80
50 829 21.83 11.85
49 818 21.25 11.70
48 833 22.04 11.91
47 827 21.72 11.83
46 829 21.83 11.85
45 831 21.93 11.88
44 826 21.67 11.81
43 830 21.88 11.87
42 818 21.25 11.70
41 826 21.67 11.81
40 823 21.51 11.77
39 818 21.25 11.70
38 826 21.67 11.81
37 824 21.56 11.78
36 827 21.72 11.83
35 825 21.62 11.80
34 823 21.51 11.77
33 824 21.56 11.78
32 820 21.35 11.73
31 825 21.62 11.80
30 824 21.56 11.78
29 831 21.93 11.88
28 825 21.62 11.80
27 831 21.93 11.88
26 833 22.04 11.91
25 830 21.88 11.87
24 828 21.77 11.84
23 829 21.83 11.85
22 832 21.98 11.90
21 824 21.56 11.78
20 822 21.46 11.75
19 829 21.83 11.85
18 830 21.88 11.87
17 823 21.51 11.77
16 819 21.30 11.71
15 829 21.83 11.85
14 828 21.77 11.84
13 822 21.46 11.75
12 815 21.09 11.65
11 822 21.46 11.75
10 817 21.20 11.68
9 825 21.62 11.80
8 816 21.15 11.67
7 824 21.56 11.78
6 826 21.67 11.81
5 822 21.46 11.75
4 831 21.93 11.88
3 820 21.35 11.73
2 838 22.30 11.98
1 853 23.11 12.20
Average: 829.65
StdDev: 11.71
Min: 799
Max: 855
Spread: 56
True MV: 829.65
Shots/sec: 0.07
Group Size (IN): 0.00
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looks good to me for hunting, at ~ 6.5% ES it may not be up to FT or benchrest contests though i dont shoot either so cannot be certain. I just recall seeing "4%" as the number to shoot for if one was punching paper. Since you are hunting, .25" or less, probably less, is not likely to matter.
string looks nice to me and unless you want to tinker, call it done and go toss lead. ;D
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That string doesn't look bad at all, except when the velocity starts climbing. Just try to figure out the POI change from ~820fps to 850fps because that 30fps will make a difference at 45 yards. 88 shots is great though.
I shoot the JSB 15.89 Jumbos in my stock Gauntlet. It liked this pellet the best. My shot string is much tighter than yours for 40 shots with an 9fps maximum spread, but most shots are only about 3, 4fps apart, and SD was 2.8 I think. Avg. was 801fps, 22.6fpe. I usually take 60-65 shots before refilling, and the POI does not change. I just didn't want to waste all my JSB pellets on the Chrono and stopped at 40 shots because I am down to 1/4 tin of the 15.89's. I don't see the need to upgrade it or tune it since the factory regulator on mine is doing a great job. The gun is a tack driver at 25 yards - same hole usually or small ragged hole. I have not shot it at longer distances yet but I suspect 1/2" at 40-45yds with 5-10mph wind. Took 18 Starlings with it this winter.
Harry
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I'll probably tinker with it a little bit to fine tune things. I usually hunt with jsb 18 grain but I might look at the 15 gr pellets to keep my fps close to the Crosman. Thanks for the replies
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Northern Kentucky starlings should be very afraid :D
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Northern Kentucky starlings should be very afraid :D
Good to see another northern kentuckian, I was wondering the rest of us were ;D
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Was beginning to think there were no others! Lots of bewildered looks & comments whenever I show up with an airgun at any of the local ranges.
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Your gun will shoot 23.22 ft/lb at that reg pressure, you could lower your reg pressure or increase hammer spring for a flatter string
normally people adjust the hammer spring till they reach the max velocity for the reg pressure for a low ES
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i agree your tuned well below the knee therefore when you come off the regulator your seeing big gains in FPS. I would lower the reg pressure or turn the adjuster in 1+ turns
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Same in Texas Guy's. Strange look when I show up with pcp.
Have won a few bucks from the ar shooters that make fun of it.
The .257 kicks their butts at the 100 targets every time. LOL 8)
Knife