Tuning FX Impact same tune for 25 and 18?? Help requested…

[Smok3y]

Picked up an Impact MKII 600mm.

Has anyone found a tune that works well for both 25RD and 18gr? I tried starting out today, getting the speed up on the 25, but I couldn’t get the 18 slow enough on the same tune. Is it possible without making changes to the screw adjustment hammerspring?

The thing I loved about my Crown was that I could should both amazingly well on the same tune. 25s on Max and 18s on low and didn’t have to change anything but the power wheel.

 

[countymm]

The crown definitely has the ability for a wider range of energy tune thanks to the transfer port adjuster (1,2,3 on MK1 : High, Med, Low on MK2). The impact does not have that adjuster. But, I still think it's possible for one tune to work on both pellets, as they are not DRASTICALLY different weights. Turn the hammer wheel to max. Test 25gr speed. Start lowering regulator (requires a shot in between each adjustment as the plenum will still have the pre-reg-adjustment air pressure in it) until you reach about 20fps over your desired speed. Then lower the hammer wheel until you get close to the speed you want for 25gr. Then keep lowering the hammer wheel to get an ideal speed for 18.1gr. IF the minimum setting doesn't lower the power enough for ideal 18.1gr speed you will have to adjust the range of the hammer wheel via the hand screw on the side of black by the 0-5 range. That handscrew is what changes the range of the wheel. You can adjust with either the macro (wheel) or micro (hand screw). They do the same thing. I use the hand screw a LOT at the range (along with my chrony) when I'm attempting to get an exact speed. Roll the screw upward to decrease power; downward to increase power.

 

[qball]

Why not just use the hammer spring power wheel? On my dreamtac compact I have HS 1 for crosman 7.9, HS 5 for 10.3 and hades and HS 11 for 13.4 all at the same speed and zero. Incredibly reliable/repeatable and impact is no different. I don't like to use the TP power on the front since I have far more control over speed for different ammo with the HS wheel.

On that note the power wheel from FX is soft aluminum so might want to get one of Montster power wheel with steel HS preload ramp. It has proven to be ver consistent especial if the gun is tuned for high power like my slug guns which all have hammer springs maxed out which chewed up the FX HS wheel in a hurry.

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[Smok3y]

Why not just use the hammer spring power wheel? On my dreamtac compact I have HS 1 for crosman 7.9, HS 5 for 10.3 and hades and HS 11 for 13.4 all at the same speed and zero. Incredibly reliable/repeatable and impact is no different. I don't like to use the TP power on the front since I have far more control over speed for different ammo with the HS wheel.

On that note the power wheel from FX is soft aluminum so might want to get one of Montster power wheel with steel HS preload ramp. It has proven to be ver consistent especial if the gun is tuned for high power like my slug guns which all have hammer springs maxed out which chewed up the FX HS wheel in a hurry.

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That was actually my point. I couldn’t get them close enough where I could switch between the two pellets with just the power wheel on the Impact. I do have the Monster wheel and it is much better than the FX upgrade!

The Crown was easy with just the wheel and I never had to adjust the TP port unless I was testing out more speed options.

I haven’t had time to go back out yet, but I’m going to flip the barrel over to the Slug port and do some testing next. It may just be that I will have to lower the speeds I was trying to get at the high end. I know I can shoot both if I keep the high end low enough. Was hoping someone had some thoughts on how fast they had the 25s shooting while still being able to just power down with only the wheel and still shoot 18s

No big deal this is what testing is for. I’ll figure it out.

 

[Payne]

That was actually my point. I couldn’t get them close enough where I could switch between the two pellets with just the power wheel on the Impact. I do have the Monster wheel and it is much better than the FX upgrade!

The Crown was easy with just the wheel and I never had to adjust the TP port unless I was testing out more speed options.

I haven’t had time to go back out yet, but I’m going to flip the barrel over to the Slug port and do some testing next. It may just be that I will have to lower the speeds I was trying to get at the high end. I know I can shoot both if I keep the high end low enough. Was hoping someone had some thoughts on how fast they had the 25s shooting while still being able to just power down with only the wheel and still shoot 18s

No big deal this is what testing is for. I’ll figure it out.

My M3 is the same as yours to low for 25.4 and to fast for 18.1.

 

[Vetmx]

The fact that RD’s like speed is the main thing that’s going to hurt you. I recently sold an Impact that the guy who bought it wanted me to set it up so he could shoot both 33.95‘s and 25.4’s by only playing with the hammer wheel. That’s a big swing just like what you are trying to accomplish. I told him that it might be possible but at least one weight or possibly both are not going to be optimal tunes for each weight pellet. There are two approaches. One is set the gun so that it’s shooting the 25gr at the regs plateau speed and the speed you want with your wheel on its max. Then go down to one on the wheel and see if it’s slow enough. If it works speed wise, they will both be jacked up tunes but it may be good enough for you. One will be on the regs plateau, not good, and one will be way below the knee, also not good. What I did was I started off with the heavy pellet shooting let’s say 930fps. That’s with my wheel on max and was the top speed for that reg setting. I used the hammer screw, MKll or the micro on a M3 to back the gun down to let’s say 890fps +or-. Now with my wheel still on max, the gun is tuned to the knee. Now when you start backing the wheel down, because you are already at the knee, you have a chance of seeing better velocity drops with the lighter pellets. So in the end with the wheel on max with the heavy pellets, you are sitting on a optimum tune. Now only your light pellet tune is a wonky.

 

[qball]

That was actually my point. I couldn’t get them close enough where I could switch between the two pellets with just the power wheel on the Impact. I do have the Monster wheel and it is much better than the FX upgrade!

The Crown was easy with just the wheel and I never had to adjust the TP port unless I was testing out more speed options.

I haven’t had time to go back out yet, but I’m going to flip the barrel over to the Slug port and do some testing next. It may just be that I will have to lower the speeds I was trying to get at the high end. I know I can shoot both if I keep the high end low enough. Was hoping someone had some thoughts on how fast they had the 25s shooting while still being able to just power down with only the wheel and still shoot 18s

No big deal this is what testing is for. I’ll figure it out.

It IS doable but you most likely will need to change your tune. I have done that many times with different projectiles including between pellet and slugs within reason obviously.