• The AGN App is ready! Search "Airgun Nation" in your App store. To compliment this new tech we've assigned the "Threads" Feed & "Dark" Mode. To revert back to a traditional "Forum List" view, and/or "Light" mode click HERE.

For the FX tuners…how have you gotten the most efficiency out for your rifle?

Jump to latest Follow Reply
Maizen

Maizen

Member
Oct 10, 2018
1,269
503
California, United States
I want to know exactly how you’ve tuned your gun to get maximum shot count while also managing relatively good power (.25 cal to be exact). Is it better to max out the hammer spring with most minimum reg pressure possible to achieve the velocity you want…or is it better to go higher on the reg pressure and then just dial the hammer spring down so that the valve is not overpowered? 

Ted made a pretty cool video on how he tunes his on his vlog channel…but I want to know what you’ve done. I more so want to know what you did to your Dreamline…but other FX tunes are welcome!
 
To get efficiency you need to close the valve well before the projectile exit the barrel. Another word highest reg pressure you can get away with with shortest possible dwell time.
Click to expand...


I don't doubt that this is totally correct, I'm not that much of a tech. But if so, I'm not sure that the absolute most air efficient tune is necessarily what you want. I try to tune to achieve the greatest accurate shot count while on the reg, and I don't think that's quite the same criteria as this method suggests. Generally, I've found the most "accuracy efficient" tune to be around 95-97% of the maximum velocity at a given reg setting. I think this would yield a lower reg setting as compared to finding the lowest dwell time. But maybe not, guess it would be an interesting tinkering project.
 
Upvote 0
Highest efficiency is possible at high pressure and very short dwell, but optimizing for efficiency as the primary goal will give neither the highest shot count nor the best consistency.

The 95-97% approach described by Ed will produce a balance of good—not great—efficiency, a low extreme spread, and high shot count. Accuracy isn’t quite so easily assured but it’s the place to start.
 
Upvote 0
Ideally you find and chart the power curve at your max hammer preload in relation to various regulator pressures. For me, peak output is around 130 bar, so I like to adjust pressure higher, that way I am in a very consistent zone (low ES). And valve dwell time is very low. I run 135 bar for my pellet tune. Running higher preasure/lower dwell also significantly reduces muzzle report since the valve is shut well before the pellet leaves the barrel. And also the higher preasure/lower volume air charge has completed more of its expansion than a lower pressure/higher volume air charge would (what would be needed for equal power output but at lower pressure)



So rather than trying to bring power down from peak by increasing dwell and decreasing pressure we want to bring power down by decreasing dwell and increasing pressure. Which can also partially be dialed in with a lighter hammer strike. Ballistic data shows that the higher the velocity the more wind drift will occur. Also, High pellet speeds in the barrel will often induce accelerated fouling. So keep that in mind. Often 880-900fps is considered desireable for peak accuracy. I prefer to shoot a bit faster since I hunt in areas with little to no wind. 
 
Upvote 0
My mk2 is tuned to about 930 945 for 34 gr mk2 jsb pellets out of 700 mm reg is about 112 113 bar between 110 and 115 then I back off the power wheel one click under max and used the valve adjuster to take speed down to 905 average I'm getting 60 plus shots off a 580 cc and am running a Huma first reg at 150 on the bottle it's quiet and powerful it could be more efficient I suppose if I tuned it differently but it's accurate

sorry I'm running a impact just seen your talking about dreamline 
 
Upvote 0
Ideally you find and chart the power curve at your max hammer preload in relation to various regulator pressures. For me, peak output is around 130 bar, so I like to adjust pressure higher, that way I am in a very consistent zone (low ES). And valve dwell time is very low. I run 135 bar for my pellet tune. Running higher preasure/lower dwell also significantly reduces muzzle report since the valve is shut well before the pellet leaves the barrel. And also the higher preasure/lower volume air charge has completed more of its expansion than a lower pressure/higher volume air charge would (what would be needed for equal power output but at lower pressure)



So rather than trying to bring power down from peak by increasing dwell and decreasing pressure we want to bring power down by decreasing dwell and increasing pressure. Which can also partially be dialed in with a lighter hammer strike. Ballistic data shows that the higher the velocity the more wind drift will occur. Also, High pellet speeds in the barrel will often induce accelerated fouling. So keep that in mind. Often 880-900fps is considered desireable for peak accuracy. I prefer to shoot a bit faster since I hunt in areas with little to no wind.
Click to expand...

Could you define dwell time?
 
Upvote 0
Ideally you find and chart the power curve at your max hammer preload in relation to various regulator pressures. For me, peak output is around 130 bar, so I like to adjust pressure higher, that way I am in a very consistent zone (low ES). And valve dwell time is very low. I run 135 bar for my pellet tune. Running higher preasure/lower dwell also significantly reduces muzzle report since the valve is shut well before the pellet leaves the barrel. And also the higher preasure/lower volume air charge has completed more of its expansion than a lower pressure/higher volume air charge would (what would be needed for equal power output but at lower pressure)



So rather than trying to bring power down from peak by increasing dwell and decreasing pressure we want to bring power down by decreasing dwell and increasing pressure. Which can also partially be dialed in with a lighter hammer strike. Ballistic data shows that the higher the velocity the more wind drift will occur. Also, High pellet speeds in the barrel will often induce accelerated fouling. So keep that in mind. Often 880-900fps is considered desireable for peak accuracy. I prefer to shoot a bit faster since I hunt in areas with little to no wind.
Click to expand...

Long-Gun. Could you reference the source of the (Ballistic data) that shows higher velocity the more wind drift? 
 
Upvote 0
Upvote 0
You must log in or register to reply here.
Top Bottom
Back
Home
Forums
Resources
Menu