Impact .25, high power..... what is your shot count?

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Drumsnguns

Member
Jun 14, 2016
959
19
North Carolina, United States
I know this question has been asked many times before but I want to ask a very specific question aimed at Impact .25 shooters who have their gun set up similar to mine.

Mine is Gen. 1 with an X-liner A, set to 145-150 Bar on the reg., HST balanced to that reg. setting, and getting 895 ave fps., (ES-7 and SD-1), with JSB MKII? Bottle pressure 220 Bar to start, down to 150, where it goes off the reg. Power wheel at MAX and valve just under 4 bars. 

So with that, what kind of shot count are you high power shooters getting?

I'm asking because I'm consistently getting sub-MOA groups all the way out to 75 yards, with weighed pellets. My 75 y groups are around 0.5" 

BUT I'm only getting around 23 or so shots.

I'd like to get more shots but I'm hesitant to make any changes. I mean this is the first time since I bought this gun, (in 2016), that I wouldn't be nervous to compete.

I am going to take a caliper measurement of the valve Knob then try hunting for the efficient "sweet spot" in hopes of keeping the speed and ES/SD.

Thanks,

KP
 
I have a 25 cal FX Impact X Gen 2 700mm. Regulator set around 147 bar. Shoots 34gr JSB Heavies MK2 at around 895fps consistently. Pretty similar to your setup.

From a 250bar fill, I get 3.5 magazines worth of shots - 3.5x16 = 56 shots approximately. Since you shoot from 220bar down, assuming a linear relationship, you should get - (220-147)/(250-147)*56 = 40 shots approximately. 

23 shots only sounds low. You could be wasting air somewhere. Also, the FX gauges are notoriously inaccurate, so those readings might not be spot on and it could affect your pressure readings, fills and shot counts.




 
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I'm shooting through a 600mm barrel but getting 895 fps

I have changed out the FX gauges for Huma and I know that the bottle gauge now is right with my Airhog Tank's gauge. I think that the reg gauge is very close to the bottle gauge as well. Shots start to drop right around 150 on the bottle gauge when I go off the reg which looks to be at maybe 148-149 bar, give or take.

I do notice that when I fire a shot the gun is loud. It has that "excess air" sound. I just can't explain the great ES?SD numbers and tight groups.



Thinking I need to go back and mess with the valve setting. But I'm tempted to just leave it alone and sacrifice a few shots for performance.


 
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Quick update:

I messed with the valve some more but I went back to setting it to 10.27 mm out which looks to be 3.5 lines on the scale. I did fill a bit more up to about 240 bar, give or take, and got 33 shots by 160 bar, (ran out of pellets in that weight), I calculated between 2-3 bar per shot, (if my math is correct), so I figured I could get between 5-8 more shots before going off the reg. So guestimating, 37-41 shots before hitting the reg bottom.

My gun seems to group best at 145-150 bar. So that's where it stays. It looks like I'm getting the proper number of shots for this power setting. I don't want to add shots by sacrificing accuracy.

This morning's chrony readings. Note that the first shot after sitting for 2 days (hurricane force winds outside yesterday), I'm seeing little to no creep.

1 900 Ave: 902

2 908 ES: 8 

3 906 SD: 2

4 903 Pellet Weight: 33.5 gn

5 904

6 906

7 900

8 901

9 901

10 900

Target with R to L Wind at around 5 mph and gusting

1555861598_20875832435cbc905e8c5559.08991371_65 yd target.jpg


65 y with MKII 34.3 gn weighed and lubed. The 4 first shots are in one hole measuring 0.375"



The extreme shot to the right I think was when the wind died just before I shot as I was holding about 1/2 mdot right.. Or I could have just pulled it.

So I think I'll not worry too much about shot count at this point and just start enjoying the gun after a long time of tinkering with it.

Thanks for the input, guys. Very helpful.

KP
 
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