When installing the barrel shroud,does it put a slight tension on the barrel as it is bottomed out on the threads?
FX Impact X barrel tension?
- Thread starter far_shot
- Start date
I do not own an impact. But on the wildcats with the shroud which screws on the end of the barrel, there is only a O-ring centering it on the other end. So if the impact use the same method, there would be no tension on the barrel itself. There will be a litle tension on the outer tube on the barrel if the liner is thightened to much.
Upvote 0
The impact barrel is a different set up. The muzzle of the barrel is threaded for the shroud.
Upvote 0
The "liner" which is the important bit is actually under compression! unless you are talking the old "part rifled" style which I think had the thread actually on the barrel itself?
Upvote 0
Does the shroud bump up against a spot on the scope rail? If it does and can tighten more than yes. But from what I've seen I don't think they are as they can slide out easily meaning the barrel as a whole isn't tensioned. From what I've seen though so I'm not 100% sure. Technically the barrel liner inside might be but not the whole barrel.
Upvote 0
Looks like the shroud is the same style as the Wildcat MKII...it fixes only at the front - muzzle end with threads - on the barrel nut for lack of a better term.
It should bottom out on that nut rather than on the sleeve. If you crank on the shroud too much when tightening it, you could exceed whatever torque you used when you secured the barrel liner.
That nut only needs to be firmly snug, and the shroud just lightly snug. That worked well for me on the Wildcat.....I never had problems with it loosening up on it's own.
https://youtu.be/Be_Lq35MFDQ
Upvote 0
Well duh,all I had to do was take a closer look. The shroud is about 1/2 inch short of touching the barrel breach block. So now I wonder if a precision spacer was slid into that gap, that was a couple thousants longer than the gap ...to actually put tension on the barrel....would it change the harmonics. This was a trick that centerfire bench rest users did and it works well. There are three cannons in the area made from the same barrel tubing and mine is the only one with a tensioned barrel inside the outer tube. It out shoots the other two so bad that there is no contest.
Upvote 0
Just to add some general information, you always want tension (stretch) on the barrel and never compression. Tension makes the barrel more rigid while compression greatly exaggerates harmonic distortion.
Upvote 0
I took an even closer look. The barrel is captured in the liner by the barrel muzzle nut...and is under compression! The shroud simply threads onto the exposed threads of the barrel nut. The tighter it is,the more compression on the barrel tube. Seems so wrong, but that's the way it is. I would say don't get crazy with tightening the moderator or the shroud.
Upvote 0
I saw this early on with my smooth x barrels. I didn’t
say anything because I thought maybe it was a local (Australia) problem. I bought what you in the US would have as a air stripper from FX to make my own shroud. That piece when treaded onto the barrel doesn’t tread all the way home. So the more you tighten the shroud the more you tension the liner. Whenever I attached an air stripper accuracy was shocking. If I didn’t use the shroud and put the airstripper direct on the barrel it treaded all the way up to the barrel sleeve and tightened against it. Then accuracy was good. I only use the shrouds now with a different way of supporting them and now have no problems. Interesting to read this after so long dealing with the issue thinking it must be just me.
say anything because I thought maybe it was a local (Australia) problem. I bought what you in the US would have as a air stripper from FX to make my own shroud. That piece when treaded onto the barrel doesn’t tread all the way home. So the more you tighten the shroud the more you tension the liner. Whenever I attached an air stripper accuracy was shocking. If I didn’t use the shroud and put the airstripper direct on the barrel it treaded all the way up to the barrel sleeve and tightened against it. Then accuracy was good. I only use the shrouds now with a different way of supporting them and now have no problems. Interesting to read this after so long dealing with the issue thinking it must be just me.
Upvote 0
Upvote 0