DISCLAIMER: If you decide to follow the below installation instructions, this will be at your own risk. Neither I nor anybody else, except yourself, will be liable for any accident in relation with these instructions. Make sure you follow ALL the usual safety rules when you work on your air rifle.
Yeah, I know, the Streamline is not a hot topic anymore Nevertheless, there might still be people who haven’t tuned theirs yet, because they’ve been lacking a how-to guide. Hence this post.
A few months ago, I sent Chuck a pm, and asked him if he would accept to guide me for the installation of the Huma reg on my FX Streamline .22 cal. He first tried to make me replace the SL with a Dreamline .25 cal
But I explained that it would be tough to sell the SL. He then kindly accepted to help and provided very detailed instructions. 99% of what follows was provided by him. I just added a few comments here and there.
FX Streamline Exploded View Drawing : https://fxairguns.com/wp-content/uploads/2019/10/streamline.pdf
A. Installation of the Huma Regulator
1. Remove the dust cover from the air pressure gauge and slowly loosen the gauge 1/2 turn to bleed the air tube. Use a 11mm open end wrench that is thin enough to fit on air pressure gauge nut (grind if necessary). Once all the air is out, re-tighten the gauge and replace the dust cover.
2. Unscrew the air tube.
Comment: on a FX SL .22, the air tube is shorter than on the .25 cal. Therefore, remove the action from the stock first to have a stronger grip on the tube.
3. Press the open end of the air tube against a pillow… Insert the fill probe into the air tube and then SLIGHTLY and SLOWLY open the valve on the scuba tank. This will pop the old factory regulator out of the air tube onto the pillow. CAUTION: Keep the open end of the air tube pointed at the pillow for safety.
4. Put a small amount of silicone grease on the O-rings on the Huma regulator, then insert it into the air tube with the brass adjustment screw facing forwards, and then insert the 7mm plenum spacer ring.
Comment: The vent hole of the reg must be at the 12 o’clock position, as per the instructions provided on the Huma website.
5. Now screw the air tube back on the rifle and fill it up to 230 bars.
B. Removal of the Hammer Spring Tension Adjuster
1. Remove the HST adjustment nut (B14 on the FX SL parts drawing). The nut usually has to be heated up to loosen the Loctite thread lock used at factory. Just heat it up with a micro torch and turn it counter clockwise with a 5mm Allen wrench. CAUTION: Be very careful and make sure the nut is hot enough. Turn it a little at a time until you get it all the way out. You do not want to strip out the hole where the Allen wrench goes!
Comments:
- I used a high-quality wrench, like the WERA Hex-Plus 013334, and unscrewed this nut very slowly. There wasn’t a lot of thread lock on my rifle, and therefore I didn’t have to use the micro torch.
- If you want to get a spare nut before doing this operation then you can order one from Bagnall & Kirkwood (UK).
2. Next after everything cools off, clean up the threads using Acetone to remove the old thread lock junk.
C. Adjustment of the Hammer Spring Tension
1. Begin to screw the HST nut into the block and make a registration mark at the 12:00 position on the face of the nut where it just begins to screw. This will give you a reference point.
2. Now using the reference mark on the nut, screw it into the block say four full turns using the mark as your guide.
3. So now that you have the HST adjuster four full turns in (one complete rotation equals a “full turn”.), shoot a few shots over your chronograph, then turn it 1/2 turn in, shoot a few more shots over your chrono, etc. Keep doing this until the velocity reaches its peak. At this point you can determine if that is high enough velocity for your pellets or not.
4. If the velocity is too high then you can turn the hammer spring nut counter clockwise to lower the velocity to your desired setting. For a .22 rifle shooting the JSB 18 grain pellets your velocity should be 880-890 fps…no more than 900 ft/s or they will not be too accurate.
Comment: As recommended by other knowledgeable airgunners on YouTube and forums, you should actually lower the velocity (~3-5% lower than the peak velocity, also called “plateau” velocity) in order to avoid waste of air.
5. If the velocity is too low for your pellets then you will have to remove your regulator and set it up say 1/4 turn higher (counter clockwise = higher pressure). See instructions provided by Huma-Air: How to Adjust the Huma Reg Pressure
6. Setting the reg pressure higher will require you to adjust the hammer spring tension all over again using the method described above, until you find the peak velocity and then you can reduce it as necessary by turning the tension lower.
7. Once you get your rifle set up to shoot your pellets at the velocity you want, then you may put a tiny drop of Mild thread lock on the threads by the hammer spring nut with a tooth pick, which will hold it in place so that it will not back out on you from vibration. This will necessitate heating it back up if you want to readjust it in the future, but I think you will find that once you have it set where you want it you will not have any reason to go back later to re-adjust it.
Comment: Another method, found on the Internet, consists of using the FX Streamline Rear Cap UK – part# 16043 – as a jam screw behind the FX Streamline Hammer Spring Adjuster – part# 11541 – in order to avoid the use of Loctite blue each time you adjust the hammer spring tension. I’ve used this method and it has given an excellent result.
Thanks to Chuck’s clear instruction, I replaced the factory reg with the Huma reg in a very short amount of time and safely. I want to thank him once again for his patience and for the time he took on a Saturday night to write what I needed for a successful installation.
Now, once you have installed your new Huma reg, you will have to test the precision of your rifle at this reg pressure and at this velocity. You might have to change the velocity, and may be the reg pressure, until you obtain very tight groups. There are few good videos and posts that talk about barrel harmonics, “knee” velocity, efficiency, pellet stabilization, etc.
Yeah, I know, the Streamline is not a hot topic anymore Nevertheless, there might still be people who haven’t tuned theirs yet, because they’ve been lacking a how-to guide. Hence this post.
A few months ago, I sent Chuck a pm, and asked him if he would accept to guide me for the installation of the Huma reg on my FX Streamline .22 cal. He first tried to make me replace the SL with a Dreamline .25 cal
But I explained that it would be tough to sell the SL. He then kindly accepted to help and provided very detailed instructions. 99% of what follows was provided by him. I just added a few comments here and there.FX Streamline Exploded View Drawing : https://fxairguns.com/wp-content/uploads/2019/10/streamline.pdf
A. Installation of the Huma Regulator
1. Remove the dust cover from the air pressure gauge and slowly loosen the gauge 1/2 turn to bleed the air tube. Use a 11mm open end wrench that is thin enough to fit on air pressure gauge nut (grind if necessary). Once all the air is out, re-tighten the gauge and replace the dust cover.
2. Unscrew the air tube.
Comment: on a FX SL .22, the air tube is shorter than on the .25 cal. Therefore, remove the action from the stock first to have a stronger grip on the tube.
3. Press the open end of the air tube against a pillow… Insert the fill probe into the air tube and then SLIGHTLY and SLOWLY open the valve on the scuba tank. This will pop the old factory regulator out of the air tube onto the pillow. CAUTION: Keep the open end of the air tube pointed at the pillow for safety.
4. Put a small amount of silicone grease on the O-rings on the Huma regulator, then insert it into the air tube with the brass adjustment screw facing forwards, and then insert the 7mm plenum spacer ring.
Comment: The vent hole of the reg must be at the 12 o’clock position, as per the instructions provided on the Huma website.
5. Now screw the air tube back on the rifle and fill it up to 230 bars.
B. Removal of the Hammer Spring Tension Adjuster
1. Remove the HST adjustment nut (B14 on the FX SL parts drawing). The nut usually has to be heated up to loosen the Loctite thread lock used at factory. Just heat it up with a micro torch and turn it counter clockwise with a 5mm Allen wrench. CAUTION: Be very careful and make sure the nut is hot enough. Turn it a little at a time until you get it all the way out. You do not want to strip out the hole where the Allen wrench goes!
Comments:
- I used a high-quality wrench, like the WERA Hex-Plus 013334, and unscrewed this nut very slowly. There wasn’t a lot of thread lock on my rifle, and therefore I didn’t have to use the micro torch.
- If you want to get a spare nut before doing this operation then you can order one from Bagnall & Kirkwood (UK).
2. Next after everything cools off, clean up the threads using Acetone to remove the old thread lock junk.
C. Adjustment of the Hammer Spring Tension
1. Begin to screw the HST nut into the block and make a registration mark at the 12:00 position on the face of the nut where it just begins to screw. This will give you a reference point.
2. Now using the reference mark on the nut, screw it into the block say four full turns using the mark as your guide.
3. So now that you have the HST adjuster four full turns in (one complete rotation equals a “full turn”.), shoot a few shots over your chronograph, then turn it 1/2 turn in, shoot a few more shots over your chrono, etc. Keep doing this until the velocity reaches its peak. At this point you can determine if that is high enough velocity for your pellets or not.
4. If the velocity is too high then you can turn the hammer spring nut counter clockwise to lower the velocity to your desired setting. For a .22 rifle shooting the JSB 18 grain pellets your velocity should be 880-890 fps…no more than 900 ft/s or they will not be too accurate.
Comment: As recommended by other knowledgeable airgunners on YouTube and forums, you should actually lower the velocity (~3-5% lower than the peak velocity, also called “plateau” velocity) in order to avoid waste of air.
5. If the velocity is too low for your pellets then you will have to remove your regulator and set it up say 1/4 turn higher (counter clockwise = higher pressure). See instructions provided by Huma-Air: How to Adjust the Huma Reg Pressure
6. Setting the reg pressure higher will require you to adjust the hammer spring tension all over again using the method described above, until you find the peak velocity and then you can reduce it as necessary by turning the tension lower.
7. Once you get your rifle set up to shoot your pellets at the velocity you want, then you may put a tiny drop of Mild thread lock on the threads by the hammer spring nut with a tooth pick, which will hold it in place so that it will not back out on you from vibration. This will necessitate heating it back up if you want to readjust it in the future, but I think you will find that once you have it set where you want it you will not have any reason to go back later to re-adjust it.
Comment: Another method, found on the Internet, consists of using the FX Streamline Rear Cap UK – part# 16043 – as a jam screw behind the FX Streamline Hammer Spring Adjuster – part# 11541 – in order to avoid the use of Loctite blue each time you adjust the hammer spring tension. I’ve used this method and it has given an excellent result.
Thanks to Chuck’s clear instruction, I replaced the factory reg with the Huma reg in a very short amount of time and safely. I want to thank him once again for his patience and for the time he took on a Saturday night to write what I needed for a successful installation.
Now, once you have installed your new Huma reg, you will have to test the precision of your rifle at this reg pressure and at this velocity. You might have to change the velocity, and may be the reg pressure, until you obtain very tight groups. There are few good videos and posts that talk about barrel harmonics, “knee” velocity, efficiency, pellet stabilization, etc.
All the best, CHUCK
