FX 600 mm Superior STX barrel liner

[perazzisc3]

After replacing my 600 mm stx barrel liner on my Crown to a 600 mm Superior liner I experienced a loss of fps with the 25gr JSB'S.

I am aware the twist is different.

Is it normal that there is a need to re-tune? 

 

[Eaglehorn]

I would expect needing to retune it since it's a whole new barrel

 

[harrymoreland]

I guess a retune.

If that is not better, please let us know.

thank you.

 

[DShepard]

How many shots through the new liner, and how much velocity loss? My Impact has gained some speed after it's initial tune and a couple tins of pellets.

 

[perazzisc3]

I guess a retune.

If that is not better, please let us know.

thank you.

Initial few shots are disappointing,I loss up to 26 fps and e.s. increased substantially, but I will confirm performance after a tune.

 

[biohazardman]

Lets see now change pellets re-tune, change reg pressure re-tune, change altitudes re-tune, change barrel port re-tune change hammer weight re-tune, change hammer spring re-tune, change or remove moderator or shroud re-tune. So when changing the barrel I would say you will likely need to re-tune. All of these things will affect the tune of your gun so for the most part you will have to re-tune. Every now and then things won't have much of an effect so you will not need to re-tune but that is seldom the case. The only way you will know for sure is to shoot it and check.

26fps will likely not even be noticed unless you are shooting at long distance or you are shooting over a chrony. ;^).

 

[DShepard]

Did you clean the new liner? When new, my Impact had a lot of gunk in it.

 

[perazzisc3]

Did you clean the new liner? When new, my Impact had a lot of gunk in it.

I cleaned it before I installed it. It looked like a mirror after 2 felt pellets and a couple patches with ballistol.

 

[perazzisc3]

Lets see now change pellets re-tune, change reg pressure re-tune, change altitudes re-tune, change barrel port re-tune change hammer weight re-tune, change hammer spring re-tune, change or remove moderator or shroud re-tune. So when changing the barrel I would say you will likely need to re-tune. All of these things will affect the tune of your gun so for the most part you will have to re-tune. Every now and then things won't have much of an effect so you will not need to re-tune but that is seldom the case. The only way you will know for sure is to shoot it and check.

26fps will likely not even be noticed unless you are shooting at long distance or you are shooting over a chrony. ;^).

I had the oem stx liner pushing the 25gr JSB's avg. 905 fps s.d. 7 fps, after a few shots with the superior liner it was 874 - 890's.

I will re-tune and cross my fingers, before I ordered the new liner the merchant assured me how GREAT it is.

 

[jwrabbit123]

does the pellets push threw barrel easier with that the new liner if you pushed threw with a cleaning rod ?then pushed a pellet threw your other one , which has less resistance ?

I heard the new liners were just a bit larger diameter , so this would make sense if it was and a tiny bit of air escaped ? let us know please

 

[perazzisc3]

update

I did a rough tune and the accuracy with the 25gr JSB'S out of the superior liner appear to have increased from the oem STX liner.

I have to now tune the rifle for the hybrids to see how they perform.

 

[JoeKool]

Here’s my results, my Crown is power tuned though but accuracy is better!



https://www.airgunnation.com/topic/first-30-shots-after-installing-a-new-fx-stx-superior-25-600mm-in-my-fx-crown/

 

[perazzisc3]

Here’s my results, my Crown is power tuned though but accuracy is better!



https://www.airgunnation.com/topic/first-30-shots-after-installing-a-new-fx-stx-superior-25-600mm-in-my-fx-crown/

What reg pressure are you set at, is the hammer tension maxed?

 

[JoeKool]

Here’s my results, my Crown is power tuned though but accuracy is better!



https://www.airgunnation.com/topic/first-30-shots-after-installing-a-new-fx-stx-superior-25-600mm-in-my-fx-crown/

What reg pressure are you set at, is the hammer tension maxed?

It has a high output Huma regulator set @ 175 bar and it is “Maxed”. It is not a stock Crown.

 

[triggertreat]

Thanks Joe! I am headed in that direction coming up.

 

[Drumsnguns]

I’d shoot a few tins of pellets through a new barrel to break it in. And then if the speed hasn’t come up some I’d re-tune. Don’t rush it.