what would be a good reg pressure and other settings for a FX impact MK2 .25 using jsb 34 gr?
Reg pressure
- Thread starter villaman
- Start date
I have mine set around 145-148 more or less and shooting the 34s at 880+ fps with excellent accuracy averaging 1/2inch groups and smaller at 60 yards and getting 64 regulated shots per fill.
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I have to go higher than 140 (not a lot higher) when shooting .22 and .25 slugs out of my MKII.
Like sonny, I also have to set my reg just under 150 to get the 34s to around 900 FPS
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Reg pressure setting will depend on three factors:
1. Length of barrel.
2. Weight of pellet/slug.
3. Desired velocity.
You can't really tell someone they don't need to go higher than 140bar without knowing these things.
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I also have the MKII with the 700mm barrel in .25 caliber. I have mine set at 145Bar, hammer spring pre load screw almost maxed out and then backed off about 1/2 turn, the valve adjuster is at 3 1/4 lines or 8.5mm. With the power wheel set on max and these settings, I'm getting very good groups consistently... 3/8" at 40yds with the JSB 33.95 MKII's and a velocity of 930fps. Of course every gun will be different but this is a good starting point depending on what you want for shot count and velocity. I get about 80-85 shots per fill with this tune but I have the 580cc bottle too. From there, where my accuracy seems to be best, I can max the hammer spring pre load screw all the way, open the valve adjuster all the way and reach velocities of 980-985 with the same 33.95 JSB MKII's. When I was doing my initial testing with this gun, I had the regulator set around 148Bar the hammer spring pre load maxed and the valve on 4 lines and was getting 990fps, accuracy was pretty good but not as good as it is now. Test everything thoroughly and take good notes! I hope this helps at least a little bit. Have fun with your Impact, they're a blast!
Stoti
Stoti
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