How did you lower the power on your Air Ranger?

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I have a .25/50fpe Air Ranger, and I wanted to improve shot count and drop the power to meet my needs a little better. So I adjusted the hammer striker and effectively lowered the peak power of the gun to produce ~35 shots 865-895-865, which it does between 2700-1900psi. That is with JSB 25.4gr pellets.

What have you done with your Air Ranger to increase the shot count at the lower power? (In other words, flatten out the shot string.).

Do I need a lighter spring and pull the striker back into the hammer? If so, the information on what spring you used would be helpful. 

Do I need to change the delrin hammer spacer to a thinner one that offers less spring preload? If so, a source for the delrin spacers would be helpful? 

Do I need to change the transfer port to one from a .22/40fpe air ranger? That one, I assume I could get from AoA

Thanks for your help!

 

[YamahaR1]

I have an air Ranger in 25 cal. Great air rifle and is a hammer if you want it to be. If you don't mind to tinker a little bit there was some things I did to mine to help with consistency. I broke down the air rifle and pulled the hammer out along with the spring and TP. I cleaned the inside of the tube where the hammer rides real good and then polished it. I then sanded the hammer with 500grit (be sure not to take the hammer down in one spot by sanding to much, your just looking to make it consistent) I then went to a 1000 grit just to get it super smooth. Then I polished the hammer too where you can see your reflection in it. This really makes the hammer travel down the chamber really nicely minimal amount of drag and very consistent. When you pull the hammer out you will notice the factory machine work is good but there is imperfections, so the idea is to get rid of that to help with shot to shot consistency. I also took the spring and flattend the ends using a dremel. The idea here is when you stand the spring up on its end it stands perfectly straight in all directions. This is to help push the hammer evenly down the chamber before it hits the valve. You will notice that most springs have a tail on them and this will make the spring lean or even fall over if you try to stand it on its end. Most of your high end custom guns these type of things are already done when you buy them. But factory line type guns do not, this is not saying they are poorly made. Just hard to do that to a air rifle that's in a factory line so to say. Hope this may help you with your question. More than happy to help if you have any questions. 

 

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Those are good tips. I had heard about polishing the hammer before, but not about leveling the spring.

However, my question is not so much about shot-to shot consistency, as I feel that is pretty good. From any given shot to the next there is typically 0-4fps change.

So that means if I start from a 3300psi fill the rifle is capable of, I will go through a hundred shots that form a nice smooth curve up to its peak power around 2300psi, but the velocities of the shots are too low to be "usable" until I get to about 2700psi. What I would like to do is tune the rifle's performance to get the most possible shots, say within 4%ES, out of the entire pressure range 3300-1900psi, or as much of that as I can use, somewhere in the 40-45fpe range. 

 

[YamahaR1]

Couple things to consider when tuning your air rifle. First is the reason your shots are too low velocity at 3300 psi is because you have the hammer spring down low to achieve your desired velocity. So that being said you should start at a lower fill pressure say 2800 psi. I know you want high shot count and a 40-45 fpe which is doable but your starting pressure is too high. But if you started at 3300 psi you would need to turn your hammer spring pressure up but then you would get a higher fpe and you velocity curve would drop off sooner. So it's a balancing act you have to sacrifice one a little to get what your looking for. If you go regulated then you can fill as high as you want, but going off of pressure and hammer force you need to balance the two to get your desired fpe. I tuned my Benjamin Marauder .25 at the same fpe your shooting for and my starting fill pressure was 2800psi and I had good shot count off that fill. Could never get what I wanted filling it higher or my velocity would be too low. I would try different start points to tune your air Ranger. But you said 2700psi was when your shots were usable so that's why I said try the 2800psi. Also you can start at that point and turn your hammer spring pressure up a 1/4 turn at a time to try and bump your velocity up just a touch at 2800psi. Then hopefully your curve is a bit flatter and you don't go over your 45fpe mark. This is something you'll have to play with before you get it right where you want it. Anyways hope that helps you out a bit. If you have anymore questions I'll see if I can help!

 

[mobilemail]

How did you "adjust" hammer spring on an air ranger? As far as I know that can only be changed by changing the delrin preload inserts, unless you made or bought an adjuster. So far as current hammer spring preload, I am still using the same delrin spacer that was in the gun, the one that produces 50+fpe when the hammer striker is pulled all the way into the hammer. So I haven't "reduced hammer spring" at all, I have only adjusted the striker to protrude from the hammer face. 

I'm aware that what I am after is a balancing act, that is why I asked for specifics on how others may have achieved the balance.