JDS Airman 13 ci 1600 PSI Regulated Chrony String
Interested in what the experts think about this. Especially the low values.
Talon SS, 12 inch barrel, JDS Airman Tank, 13 cu, .177cal. 10.4 Crosman Premiers, using CO2 adapter. PW is power wheel setting. With this set up the velocity max is reached at PW setting 6. At 12 is is just louder and the same velocity.
A consistent drop does not start until ~1200 psi. The resolution of the tiny gage is not very good.
I was a little disappointed with the velocity. I had hoped 1600 psi to get me above 800 fps.
I think the regulator is working because when you fill the tank you hear a tiny click right as you pass 1600 psi.
I also think the CO2 adapter is choking the flow and that may be why the FPS does not drop off starting at 1600 psi.
1 PW 2 490 3000 psi
2 PW 4 550
3 PW 6 734
4 710
5 713
6 654
7 729
8 731
9 735
10 717
11 712
12 729
13 729
14 733
15 731
16 730
17 713
18 634
19 729
20 729
21 729
22 701
23 721
24 669
25 725
26 727
27 737
28 717
29 724
30 634
31 732
32 725
33 723
34 715
35 727
36 730
37 720 2000 psi
38 730
39 732
40 652
41 729
42 718
43 703
44 698
45 720
46 724
47 691
48 712
49 699
50 704
51 717
52 733
53 712
54 725
55 718
56 717
57 724
58 739
59 605
60 705 1600 psi
61 733
62 740
63 733
64 726
65 734
66 740
67 729
68 733
69 724
70 724
71 715
72 719 1200 psi
73 703
74 701
75 694
76 685
77 685 1000 psi
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Viewing 9 replies - 1 through 9 (of 9 total)
I wouldnt have thought that the 13ci tank would give that many shots at a higher output. I have a 950psi output 13ci tank currently on an RWS850 and while velocity is lower (around 750fps with 7.9gr) I get a gazillion shots. Havent done a proper chrony string on it as of yet….
Been looking at a shorter 48ci tank with a 1400psi reg on it for the Talon, should get a fair number of shots I’d reckon.
Rob, your picture makes you look fatand ugly 😯 , you really need to drop some pounds for the sake of your health.
So you use the Airforce CO2 adaptor with the JDS tank?
That sounds like an easier cheaper way to shoot low power than to buy the Micro tank from Airforce. I already have an Airforce CO2 valve.
Post pictures of how this thing goes together so we can understand it better. 😕
Took co2 adapter apart. Drilled another hole 180 deg from the other. Cleaned it up and put it back together.
First shot was very low in noise. Second sounded pretty good. So I put the chrony on to start measuring velocity. Third shot was low and valve started hissing. So it looks like I didn’t clean this thing up enough and put a shaving into the valve. Looks like I have a valve to take apart and parts to order.
I should have bought a talon tank in the first place. I just wanted a little more power than my micrometer for less scope adjusting on longer shots.
Very nice.
I wouldnt have thought that the 13ci tank would give that many shots at a higher output. I have a 950psi output 13ci tank currently on an RWS850 and while velocity is lower (around 750fps with 7.9gr) I get a gazillion shots. Havent done a proper chrony string on it as of yet….
Been looking at a shorter 48ci tank with a 1400psi reg on it for the Talon, should get a fair number of shots I’d reckon.
Want to add that I did go to my micro meter tank and shot 20 times. They were all consistent around 590 fps. So chrony and gun seem okay.
Maybe I have some loose metal shavings or something in that co2 adapter?
2 thoughts; I have had cps in the metal tins with a few loose fitting pellets now and then, or if those shots were fired with less time between shots (regulator may be not fully recovered/equalized from the previous shot, effectively making the second shot on lower pressure)
The timing of each shot in the string was pretty consistent. I am thinking about opening up the hole on the bottle side of the adapter. I wonder if anyone has done this before? I would just like to see what is on the other side of it before I start on it.
Want to add that I did go to my micro meter tank and shot 20 times. They were all consistent around 590 fps. So chrony and gun seem okay.
Maybe I have some loose metal shavings or something in that co2 adapter?
2 thoughts; I have had cps in the metal tins with a few loose fitting pellets now and then, or if those shots were fired with less time between shots (regulator may be not fully recovered/equalized from the previous shot, effectively making the second shot on lower pressure)
It is the ones near 660 that are bugging me.
Want to add that I did go to my micro meter tank and shot 20 times. They were all consistent around 590 fps. So chrony and gun seem okay.
Maybe I have some loose metal shavings or something in that co2 adapter?
shot string looks good. I think the internal volume of the CO2 adapter is not large enough to allow higher velocity at that pressure; not enough regulated air volume available.
Viewing 9 replies - 1 through 9 (of 9 total)
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Well I off loaded the JDS tank because I wanted more FPS. Bought a used Talon.
You are right about lower cost lower velocity. Just expect 60 shots at 700 vs 100+ shots at 600 with the micrometer. On the JDS tank you also need to rig up a buttpad.
In opening up the CO2 adapter I did that but could not follow through with a chrony string because the delrin seal was damaged by a bit of shavings from my drilling.