Hello AirgunNation Peoples,
Can the FX Dreamline .22 caliber shoot slugs well? Answer: Yes, phenomenally! Here is my definitive guide on the simple modifications and tunes that have my FX Dreamline - Bullpup .22 caliber consistently achieving a 903 fps average with Nielsen Specialty Ammo .218 23 grain HP-FB slugs, 41 fpe, 42 shots per fill, and shooting (doing my part) 1 MOA groups @ 100 yards!
THE GUN & AMMO
First and foremost, was the barrel. Running the FX 600mm Smooth Twist X system paired with the FX 600mm slug “A” liner. (500mm is stock for .22 caliber, 600mm barrel & slug liner sold separately) The tune at the time of the installation of this “slug barrel setup” was optimized for JSB 18.13 grain pellets. Which was at 140 bar AMP regulator setting and a “true MAX” hammer spring tension. Yielding 775 fps with 23 grain slugs, which was too slow and fell short on accuracy.
The need for speed!
Problem was that the internal hammer spring tension screw was already maxed out... So I keyed in on the AMP regulator pressure. First I turned it up to 150, then 160 and the velocity got slower, around 750 fps at those regulator pressures. So, I reset the AMP regulator back to 140 bar. This indicated to me that I needed more hammer spring tension. How? Like I mentioned I was already “maxed out”. Well here’s how, a simple spacer aka “washer” to add more spring tension to the hammer spring. A power tuning technique I picked up from tuning springers back in the day.
HAMMER SPRING SPACER MODIFICATION (no drilling or cutting of OEM parts required)
Step 1. Use a small 3mm thick rubber washer as a hammer spring spacer for a hammer spring tension increase.
Step 2. Place or fit into the inside of of the Dreamline’s spring guide.
Step 3. Set the internal hammer tension grub screw to 5mm (I learned this through chronograph testing later but, I’ll just tell you now)
Step 4. Reassemble
Step 5. Insure transfer port dial is set to .”25/.30” and hammer spring adjuster dial is set to “MAX”.
FYI: Cocking was smooth as stock form no catching, binding, or any indication of this modification changing anything operational. Hammer still is free-floating just added spring tension when cocked. A benefit...
Now, at this point let me remind you that the AMP regulator is set to 140 bar, transfer port is @ .25/.30, and hammer spring dial turned to MAX. With these settings chronograph testing returned 890 - 895 fps with the 23 grain NSA slugs! Wow, I was doing something right here!
Okay, I thought... She has the hammer spring tension to push the valve open, now I’ll increase the AMP regulator pressure slowly (in 5 bar increments) and chronograph test again.
FINAL AMP REGULATOR SETTING 145 BAR (which gave me the 900 fps)
FX DREAMPUP 31 SHOT STRING OVER CHRONOGRAPH USING NSA .218 23 GRAIN SLUGS
This tune gives a 903 fps average, that is 41 fpe with 23 grain slugs, and 42 shots from a 230 bar fill.
5 shots for every 10 bar of air used down to 145 bar regulator pressure.
230 - 145 = 85
85 / 10 = 8.5
8.5 x 5 = 42.5 shots per fill
Lastly, (and the best of all) after zeroing in the DreamPup and a lot of range practice. I shot my first sub MOA 10 shot group! Still in disbelief!
50 YARD 10 SHOT GROUP DREAMPUP & 23 GRAIN SLUGS
100 YARD 10 SHOT GROUP DREAMPUP & 23 GRAIN SLUGS
Like I said,”Full Disclosure”.
Needless to say, I am very happy!
Can the FX Dreamline .22 caliber shoot slugs well? Answer: Yes, phenomenally! Here is my definitive guide on the simple modifications and tunes that have my FX Dreamline - Bullpup .22 caliber consistently achieving a 903 fps average with Nielsen Specialty Ammo .218 23 grain HP-FB slugs, 41 fpe, 42 shots per fill, and shooting (doing my part) 1 MOA groups @ 100 yards!
THE GUN & AMMO
First and foremost, was the barrel. Running the FX 600mm Smooth Twist X system paired with the FX 600mm slug “A” liner. (500mm is stock for .22 caliber, 600mm barrel & slug liner sold separately) The tune at the time of the installation of this “slug barrel setup” was optimized for JSB 18.13 grain pellets. Which was at 140 bar AMP regulator setting and a “true MAX” hammer spring tension. Yielding 775 fps with 23 grain slugs, which was too slow and fell short on accuracy.
The need for speed!
Problem was that the internal hammer spring tension screw was already maxed out... So I keyed in on the AMP regulator pressure. First I turned it up to 150, then 160 and the velocity got slower, around 750 fps at those regulator pressures. So, I reset the AMP regulator back to 140 bar. This indicated to me that I needed more hammer spring tension. How? Like I mentioned I was already “maxed out”. Well here’s how, a simple spacer aka “washer” to add more spring tension to the hammer spring. A power tuning technique I picked up from tuning springers back in the day.
HAMMER SPRING SPACER MODIFICATION (no drilling or cutting of OEM parts required)
Step 1. Use a small 3mm thick rubber washer as a hammer spring spacer for a hammer spring tension increase.
Step 2. Place or fit into the inside of of the Dreamline’s spring guide.
Step 3. Set the internal hammer tension grub screw to 5mm (I learned this through chronograph testing later but, I’ll just tell you now)
Step 4. Reassemble
Step 5. Insure transfer port dial is set to .”25/.30” and hammer spring adjuster dial is set to “MAX”.
FYI: Cocking was smooth as stock form no catching, binding, or any indication of this modification changing anything operational. Hammer still is free-floating just added spring tension when cocked. A benefit...
Now, at this point let me remind you that the AMP regulator is set to 140 bar, transfer port is @ .25/.30, and hammer spring dial turned to MAX. With these settings chronograph testing returned 890 - 895 fps with the 23 grain NSA slugs! Wow, I was doing something right here!
Okay, I thought... She has the hammer spring tension to push the valve open, now I’ll increase the AMP regulator pressure slowly (in 5 bar increments) and chronograph test again.
FINAL AMP REGULATOR SETTING 145 BAR (which gave me the 900 fps)
FX DREAMPUP 31 SHOT STRING OVER CHRONOGRAPH USING NSA .218 23 GRAIN SLUGS
This tune gives a 903 fps average, that is 41 fpe with 23 grain slugs, and 42 shots from a 230 bar fill.
5 shots for every 10 bar of air used down to 145 bar regulator pressure.
230 - 145 = 85
85 / 10 = 8.5
8.5 x 5 = 42.5 shots per fill
Lastly, (and the best of all) after zeroing in the DreamPup and a lot of range practice. I shot my first sub MOA 10 shot group! Still in disbelief!
50 YARD 10 SHOT GROUP DREAMPUP & 23 GRAIN SLUGS
100 YARD 10 SHOT GROUP DREAMPUP & 23 GRAIN SLUGS
Like I said,”Full Disclosure”.
Needless to say, I am very happy!
