Huben GK1 .25 tuning for Altaros & JSB - charts and data

[weevil]

I hope they’re also shooting accurately.

 

[primaz]

Cheaper lead-frees

Less expensive is always good, but on a more serious question, are these lead free lighter and harder .25 pellets shooting more accurate than the typical JSB's,? I know "weevil" has experienced improved accuracy with the .22 GTO lead free pellets. Also is there any issues of jamming? I read on another post that one person said they have had jamming issues with the .25 GTO's?

 

[JDGriz]

@weevil @primaz I don't actually know how accurate they are; my current shooting distance is 7 meters. I used them for upping the number of shots per fill, at low power, but my new pump (the Huben pump) is actually fairly easy to use, so I moved to plain 25gr. JSBs. I've had no jams or any other issues so far.

 

[Noob with alot questions]

ty for all the data!

 

[paperp]

HI ALL GREAT INFO! BUT WHAT DO THE GROUPS LOOK LIKE?? FROM THE ALTAROS SLUGS? THANKS PAPERP

 

[steve-l]

My results with both the V1 and V3 in .25 is similar. I now shoot exclusively with the JSB 25.4 gr pellet, not lead free. I charge the guns to 310 bar and tune to about 700 FPS. I get a full (17) round mag at virtually the same speed and shoot one ragged hole at 25 meters. The gun is designed for pellets not slugs. I use the 25.4 JSB pellet as opposed to the 39 gr pellet for economy as you get 50 more pellets in a tin for the same cost. After one mag the tank pressure drops to 220 bar. I then recharge the gun back to 310 bar.

 

[Ironclad Trading]

Impressive. Thanks

 

[Kneepit]

This is absolutely perfect for me. I’m so glad you sent it! Now I have some sort of idea how to adjust for what I want!! This is awesome

 

[AGFAN]

..More charts and data, for JSB .25, 25.4gr, same procedure.
It looks like the flattest setting would be around 750-770 FPS.

View attachment 433395

View attachment 433396

View attachment 433394

0.5 Rev CW
no. Bar FPS FPE
1 345 1027 59.5
2 333 1016 58.2
3 320 1015 58.1
4 310 1014 58.0
5 302 1006 57.1
6 290 1001 56.5
7 278 997 56.1
8 268 988 55.0
9 258 975 53.6
10 247 961 52.1
11 235 950 50.9
12 223 936 49.4
13 210 917 47.4
14 197 900 45.7
15 185 875 43.2
16 173 855 41.2
17 163 834 39.2

1.0 Rev CW
no. Bar FPS FPE
1 345 950 50.9
2 333 940 49.8
3 325 932 49.0
4 317 924 48.1
5 310 920 47.7
6 300 924 48.1
7 290 918 47.5
8 284 919 47.6
9 275 922 47.9
10 267 918 47.5
11 260 920 47.7
12 251 921 47.8
13 243 917 47.4
14 237 914 47.1
15 230 911 46.8
16 223 912 46.9
17 216 911 46.8
18 210 897 45.4
19 205 892 44.9
20 197 885 44.2
21 188 876 43.3
22 181 865 42.2
23 175 852 40.9
24 167 836 39.4
25 161 827 38.6

1.5 Rev CW
no. Bar FPS FPE
1 345 820 37.9
2 337 820 37.9
3 328 819 37.8
4 323 821 38.0
5 317 820 37.9
6 310 816 37.5
7 303 816 37.5
8 298 818 37.7
9 291 817 37.6
10 286 818 37.7
11 278 814 37.4
12 273 817 37.6
13 267 819 37.8
14 262 820 37.9
15 256 821 38.0
16 251 822 38.1
17 245 826 38.5
18 240 832 39.0
19 233 833 39.1
20 228 831 38.9
21 222 835 39.3
22 217 840 39.8
23 212 846 40.4
24 207 849 40.6
25 202 853 41.0
26 196 855 41.2
27 190 854 41.1
28 185 853 41.0
29 180 851 40.8
30 174 841 39.9
31 168 834 39.2
32 163 823 38.2
33 156 812 37.2
34 153 800 36.1

2.0 Rev CW
no. Bar FPS FPE
1 340 704 27.9
2 335 699 27.6
3 330 701 27.7
4 325 696 27.3
5 320 698 27.5
6 316 695 27.2
7 312 697 27.4
8 308 698 27.5
9 304 693 27.1
10 300 692 27.0
11 296 686 26.5
12 291 696 27.3
13 287 689 26.8
14 283 688 26.7
15 279 686 26.5
16 275 684 26.4
17 273 682 26.2
18 268 682 26.2
19 265 683 26.3
20 260 684 26.4
21 255 677 25.8
22 252 680 26.1
23 248 680 26.1
24 245 682 26.2
25 242 680 26.1
26 238 680 26.1
27 235 675 25.7
28 232 678 25.9
29 228 674 25.6
30 225 677 25.8
31 222 676 25.8
32 219 680 26.1
33 215 675 25.7
34 212 674 25.6
35 209 672 25.5
36 205 671 25.4
37 202 670 25.3
38 200 666 25.0
39 196 664 24.9
40 193 656 24.3
41 190 665 24.9
42 187 669 25.2
43 185 671 25.4
44 182 671 25.4
45 180 671 25.4
46 177 677 25.8
47 174 676 25.8
48 170 682 26.2
49 167 682 26.2
50 165 680 26.1
51 162 684 26.4
52 159 688 26.7
53 157 695 27.2

2.5 Rev CW
Shot No. Bar FPS
1 345 579 18.9
2 340 573 18.5
3 335 570 18.3
4 328 567 18.1
5 325 568 18.2
6 325 565 18.0
7 320 567 18.1
8 318 562 17.8
9 315 565 18.0
10 313 563 17.9
11 310 560 17.7
12 307 560 17.7
13 304 560 17.7
14 302 561 17.7
15 300 561 17.7
16 298 559 17.6
17 293 560 17.7
18 290 557 17.5
19 286 558 17.6
20 285 557 17.5
21 283 556 17.4
22 278 559 17.6
23 275 559 17.6
24 273 559 17.6
25 270 557 17.5
26 267 557 17.5
27 264 556 17.4
28 261 557 17.5
29 259 555 17.4
30 256 556 17.4
31 254 555 17.4
32 252 557 17.5
33 249 554 17.3
34 245 550 17.1
35 240 551 17.1
36 240 550 17.1
37 238 550 17.1
38 235 548 16.9
39 232 548 16.9
40 230 548 16.9
41 228 545 16.7
42 225 546 16.8
43 224 547 16.9
44 221 543 16.6
45 219 544 16.7
46 216 542 16.6
47 215 544 16.7
48 213 538 16.3
49 210 540 16.4
50 210 538 16.3
51 205 537 16.3
52 203 535 16.1
53 200 534 16.1
54 199 536 16.2
55 197 533 16.0
56 195 534 16.1
57 192 533 16.0
58 190 531 15.9
59 190 531 15.9
60 188 529 15.8
61 186 529 15.8
62 185 527 15.7
63 183 526 15.6
64 181 528 15.7
65 180 527 15.7
66 178 526 15.6
67 175 521 15.3
68 171 521 15.3
69 170 520 15.2
70 167 523 15.4
71 165 525 15.5
72 165 517 15.1
73 163 519 15.2
74 163 520 15.2

Thanks!