FX FX Leopard liner swap from heavy liner to standard pellet liner .30cal

I recenlty purchased a 600mm .30 leopard with the tube (no bottle) and was planning on shooting slugs out of it. I had Utah Airguns tune it to shoot the Impulse Air HBT 44.5gr slugs at around 945 FPS. It shot ok but not the accuracy I was use to with shooting .30 and .25 cal pellets at the 50-100 yard range. Most of my shots are 35-120 yards and decided I was going to tune back down and shoot pellets out of it only. I think the twist rate is too fast for pellets because it appears they are destabilized and possibly corkscrewing if i shoot them at the speed i would like to shoot them at 900-935FPS. They shoot fine around 830-850FPS but as soon as i turn up the reg and hammer they start to go all over the place. I ordered a standard superior STX superior liner and am going to swap out the slug liner. The heavy liner is a 1:16 twist and the regular STX liner is 1:40 twist rate in .30cal.

Has anyone else had similar problems with the superior heavy liner with pellets, and does anyone have a video or link to how to safely change the liner on the leopard since it has compressed air around it? I know how to change the liner on my impact and wildcat but there is very little info on the leopard at this time.

Any other Leopard owners if you could let me know what reg pressure you are shooting .30 cal pellets at that would be appreciated as well. Since I had Utah Airguns tune it before I received it i dont know what the approximate factory reg pressure was. I have tried anywhere from 115-145 with no success shooting pellets at over 850FPS. I have tried 4-5 different pellets (light and heavy and all different brands)
 
I recenlty purchased a 600mm .30 leopard with the tube (no bottle) and was planning on shooting slugs out of it. I had Utah Airguns tune it to shoot the Impulse Air HBT 44.5gr slugs at around 945 FPS. It shot ok but not the accuracy I was use to with shooting .30 and .25 cal pellets at the 50-100 yard range. Most of my shots are 35-120 yards and decided I was going to tune back down and shoot pellets out of it only. I think the twist rate is too fast for pellets because it appears they are destabilized and possibly corkscrewing if i shoot them at the speed i would like to shoot them at 900-935FPS. They shoot fine around 830-850FPS but as soon as i turn up the reg and hammer they start to go all over the place. I ordered a standard superior STX superior liner and am going to swap out the slug liner. The heavy liner is a 1:16 twist and the regular STX liner is 1:40 twist rate in .30cal.

Has anyone else had similar problems with the superior heavy liner with pellets, and does anyone have a video or link to how to safely change the liner on the leopard since it has compressed air around it? I know how to change the liner on my impact and wildcat but there is very little info on the leopard at this time.

Any other Leopard owners if you could let me know what reg pressure you are shooting .30 cal pellets at that would be appreciated as well. Since I had Utah Airguns tune it before I received it i dont know what the approximate factory reg pressure was. I have tried anywhere from 115-145 with no success shooting pellets at over 850FPS. I have tried 4-5 different pellets (light and heavy and all different brands)
I tried a heavy slug liner in my 700 mm .22 impact M3 and it didn’t like pellets at all. Thought the AEA 25.4 would do well but not the case. Went back to standard liner
 
Probably be a good idea to call utah about the liner swap. I would assume the leopard is similar to the dynamic platform where the end section of the shroud is actually only a shroud and not part of the plenum. It can be removed and the liner easily accessed. I would call them to verify. What pellets have you tried ? I remember Steve from AEAC on YouTube having very good luck with AEA 50 gr at like 930 or 40 out of that liner. Don’t own a leopard but I do run my 600 mm .30 wildcat BT at 115-117 bar and it sweet spots 44.75 right around 900.
 
I have the Leopard in 600mm, but in .22. I have been thinking of going with the standard liner, but for a different reason, to shoot pellets. Instead, I purchased an FX Impact M4 Compact .22 to shoot pellets and am keeping the Leopard with the Heavy liner for heavier pellets and slugs. I am going to follow this thread, as I am curious where you end up. There is not much information out there on the Leopard!
 
Probably be a good idea to call utah about the liner swap. I would assume the leopard is similar to the dynamic platform where the end section of the shroud is actually only a shroud and not part of the plenum. It can be removed and the liner easily accessed. I would call them to verify. What pellets have you tried ? I remember Steve from AEAC on YouTube having very good luck with AEA 50 gr at like 930 or 40 out of that liner. Don’t own a leopard but I do run my 600 mm .30 wildcat BT at 115-117 bar and it sweet spots 44.75 right around 900.
I have tried JSB 44.75 they are 2nd best shooting 1.5" -2" groups at 55 yards, Hades shoot the best but has to be around 850FPS 1-1.50" groups, ZAN 48gr they are 2.5"+ groups, and JSB Heavy 50.15 are 2.5-3.5" groups. I have experimented at various different speeds and they all shoot better between 850-865, as soon as you get into the upper 8's or low 900's the groups spread way out and you get some ridiculous flyers that will be 4+" off target. I don't have a scope cam but it looks like they may be cork screwing or some type of tumbling action.

I will receive my 600mm 30cal standard pellet liner from Utah Airguns tomorrow when I get home from work. I shot the gun below the reg and cracked the bleeder screw above the reg pressure gauge and degassed the gun. I took off the moderator and the barrel cap came off with a set of snap ring pliers or small needle nose pliers, it was not overly tight. The jam nut for the liner was exposed and came off as expected. The factory heavy liner does have the FX carbon sleeve on it. I was expecting alot more work but it turned out to be very simple.

I will let you know what kind of results I have with pellets after I get the Standard/Pellet liner installed. I plan in starting with a 110-115 reg pressure and working my way up from there. I hope to have much better results with pellets after i get this Standard twist pellet liner installed.
 
I have the Leopard in 600mm, but in .22. I have been thinking of going with the standard liner, but for a different reason, to shoot pellets. Instead, I purchased an FX Impact M4 Compact .22 to shoot pellets and am keeping the Leopard with the Heavy liner for heavier pellets and slugs. I am going to follow this thread, as I am curious where you end up. There is not much information out there on the Leopard!
Liner was very easy to change see my previous reply for a few additonal details.
 
End.jpg

end cap with holes for small needle nose pliers or snap ring style pliers. It came off easily with gun degassed

Assembly.jpg

picture of end cap removed with liner jam nut and carbon sleeve
 
I have tried JSB 44.75 they are 2nd best shooting 1.5" -2" groups at 55 yards, Hades shoot the best but has to be around 850FPS 1-1.50" groups, ZAN 48gr they are 2.5"+ groups, and JSB Heavy 50.15 are 2.5-3.5" groups. I have experimented at various different speeds and they all shoot better between 850-865, as soon as you get into the upper 8's or low 900's the groups spread way out and you get some ridiculous flyers that will be 4+" off target. I don't have a scope cam but it looks like they may be cork screwing or some type of tumbling action.

I will receive my 600mm 30cal standard pellet liner from Utah Airguns tomorrow when I get home from work. I shot the gun below the reg and cracked the bleeder screw above the reg pressure gauge and degassed the gun. I took off the moderator and the barrel cap came off with a set of snap ring pliers or small needle nose pliers, it was not overly tight. The jam nut for the liner was exposed and came off as expected. The factory heavy liner does have the FX carbon sleeve on it. I was expecting alot more work but it turned out to be very simple.

I will let you know what kind of results I have with pellets after I get the Standard/Pellet liner installed. I plan in starting with a 110-115 reg pressure and working my way up from there. I hope to have much better results with pellets after i get this Standard twist pellet liner installed.
You should be money with that liner. I have had excellent luck in 3 different 30 cal fx guns with the pellet liners.
 
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Did you add the carbon fiber sleeve to the liner yourself?
No it must be standard from the factory now. I purchased it new from Utah and i know they don't give things away for free :ROFLMAO: so it must be a standard option on the Leopard. I think they should advertise something like that since most people will typically buy at least a few accessories for their new rifle. I would have been a little but frustrated if i ordered a carbon liner with my new gun and it already had one installed from the factory.
 
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