Hi Patrick, for your information the twist rate of the new .30 cal. STX Superior Liners is 1:22", and the twist rate for the .30 cal. STX Superior
Heavy Liner is 1:18". I will take this as an opportunity to speak to this issue regarding STX barrel liners. Since the beginning when FX first came out with this Smooth Twist X Barrel System there has been some confusion surrounding the names given to the different iterations of barrel liners. Such as Pellet A or Pellet B or Slug A or Slug B or Superior this or that... I have often thought that FX could clear up the present confusion and rumors and such surrounding all this by simply referring to each and every separate barrel liner by its Caliber & Twist Rate. PERIOD! And then simply make mention of how a certain Caliber & Twist rate is better for Pellets or better for Hybrids or Both, or is better for Heavy Slugs.
As of a few weeks ago I grew tired of waiting for one of the new "Superior Heavy Liners" to become available, and was on the verge of ordering a new barrel from TJ Barrel Liners. But before I ordered one I Googled "fx barrel liners" and found a new release from FXUSA showing the Caliber & Twist Rate for all the new STX Superior & STX Superior Heavy Liners thank God. So then I spoke to one of the guys at Utah Airguns whom confirmed that yes the new STX Superior Liner had a twist rate of 1:22" - I made him go in the back and measure one for me to prevent any future conflict because they don't accept returns on barrels, and I told him if they shipped me anything but a 1:22" liner that I would be returning it regardless.
So anyway, with this new STX Superior Liner's twist rate confirmed at 1:22" I went to my JBM Ballistics Stability Calculator and entered all the pertinent factors in there and lo and behold according to the Stability Calculator those FX Hybrids looked like they would be completely stable with a twist rate of 1:22"...so of course I went ahead and purchased one... and you read the results of my testing yesterday so the Stability Calculator was right on the money. You know target photos can be easily faked but photos of one Hybrid hitting the one in front of it squarely in the ass cannot! With this STX Superior Liner you can stack these .30 Hybrids on top of each other...and same goes for the FX Pellets!
Here is a photo of the JBM Ballistics Stability Calculator input box and results - and just so it makes sense to you understand that a result between 1.3 to 2.0 is great! A result of 1.45-1.5 is the US Military Reqirement. So as you can see in the photo a result of 1.66 is almost perfect! Please also understand that the result is the same all the way down to 900 ft./s, and that the projectiles stability is based on its length as well as some other factors I won't go into here now.
And here is the new twist rate chart published by FXUSA recently - I hope this clears up some of the confusion in relation to FX liner twist rate charts published in the past. I called FXUSA two weeks ago to confirm this twist rate chart is the most current up to date chart and that all twist rates are valid, and this was confirmed for me by FXUSA! So here ya go...hope this is helpful Patrick.
https://fxairguns-usa.com/fx-superior-stx-liner-twist-rates/ P.S. FXUSA also absolutely confirmed for me that all the new rifles being shipped from Sweden will have the new "STX Superior Liner" in them...regardless of caliber. What you see on that twist rate chart is what you will get in your new FX Air Rifle. Please call FXUSA if you have further questions on this subject so you can get an answer straight from the horses mouth...so to speak.
Best regards, Chuck
. From there on out she was known as HELGA THE HORRIBLE!!!
