Do you guys rotate liners?

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beerthief said:
I have Daystate and HW they shoot one hole if i do my part . Although if i tried to do things the gun isn't designed to do like 200 yards or slugs , then i guess you would index , but then your redesigning the gun aren't you ?
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I guess I should have asked why you think you need to index an fx barrel? You say you dont want an fx based on the fact you think you need to index the barrel. If you dont need to index a daystate or hw then why would you think an fx needs to be indexed?
 
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Well I guess we need to address the Real Question....
Is it REQUIRED to Index a barrel!!........No!

But Indexing the barrel is the proper way of Installing
A barrel . For the reasons given previously....
It is Also a part a Custom Barrel Tune...
Like I also re-crown all my barrels, on new guns or
Barrel Blanks....even Barrel-Liners.....
 
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beerthief said:
ok , this was fun , yes if you change the barrel, indexing would be a good thing , Still if the manufacturer does not build that way ? or maybe they do ?
I am wondering if any one indexing Edgun leshiy 1 when they change calibers ?
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I doubt daystate or anyone else building airguns in batches index each barrel on each rifle. That would create a major cost increase and production time.
 
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LDP said:
I doubt daystate or anyone else building airguns in batches index each barrel on each rifle. That would create a major cost increase and production time.
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I will go and state that they absolutely do not index guns. Anyone building guns that goes through the time and cost of indexing a barrel will be advertising that they do so as much as they can. They will need to justify their higher prices than their competitors. IMO unless they are advertised as index, they are not indexed at all
 
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rc4fun said:
The object is to find the best setting for your POI to be AT the 12 position. If that happens to be with your liner mark at 3:35 that will now be installed as the best position. 30 yds is plenty, longer the circle will get bigger. The object is to keep your POI vertical with the gun so you only need to adjust hold over/under and not need to also adjust right/left for given ranges.
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I have definitely noticed a difference in POI when "indexing" an FX barrel liner. However, with the addition of the newer Carbon Fiber liner tubes that fit snug (or can be glued), this POI difference is insignificant...
 
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The goal of indexing isn't really about correcting a divergent lateral POI. Granted it can in fact do that but so can adjustable scope mounts or shimming the scope or bending the barrel...or as is usually the case, simply twisting the windage turret of the scope.

Rather, the unique thing indexing does is it allows one to explore the nature of the barrel's harmonics to hopefully reduce the average group size. Every barrel vibrates when fired, and this vibration produces some movement of the muzzle which is one of the contributors to dispersion (scattering) of pellets on target. And no barrel is perfectly straight so that produces some bias to the direction in which the forces are acting to set up this vibration.

The idea is to orient the barrel so the vibration produces a predominantly vertical signature. Why does that help? Well, here's a practical experiment suggested by Hengehold on the accurateshooter forums:

"[The idea of]indexing a barrel in a 12 o'clock or 6 o'clock position is giving it the best possible state of harmonics to start with.

To illustrate what is happening you can try an exercise with a cleaning rod secured near the handle in a vice. First, flick the end of the cleaning rod straight up-and-down and watch the pattern of movement of the tip of the cleaning rod until movement comes to a stop. Second, try flicking the cleaning rod left and right and watch the pattern of movement of the cleaning rod until the mvmt has come to a stop. You will notice that when you flick the cleaning rod in an up-and-down motion that as the cleaning rod eventually stops whipping up and down it stays in a vertical plane. However, when you flick the cleaning rod in a lateral motion you'll notice that before it comes to rest the whip pattern of the cleaning rod is lateral then circular before eventually making a vertical motion. This cleaning rod is representing the action of a barrel that is whipping while being shot. A barrel that is whipping only in a vertical plane would have only one movement to overcome. A barrel with a lateral movement would eventually have to overcome not just the lateral movement but a circular motion and eventually a vertical mvmt as you will see demonstrated with a cleaning rod."

taken from http://forum.accurateshooter.com/threads/indexing-a-rifle-barrel.3902203/
 
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That theory of the difference in vertical movement and side movement with a cleaning rod is fine but you are seeing the change in vibration in the lateral position happen over time. A pellet will be long gone from a barrel before gravity effects that vibration pattern I would think. I would like to see some high speed camera footage of airgun barrels during the shot cycle. I dont think the barrel will be more than a cycle or two thru the vibrations before the pellet exits.
 
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This all makes sense to me after swapping barrels and adjusting headspace on Savage centerfire actions thousands of times over the years. I know nothing about FX barrels, but I am curious as to how you are able to rotate the barrel and still have the air port in the breech of the barrel line up with the port in the action. Does that brass piece on the breech end rotate freely on the steel barrel, or is there a full circle chamber around the air port in the breech, or is there something else I am not understanding? All my airguns have barrels that will only work at one position in the receiver.
 
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Geezerhood said:
This all makes sense to me after swapping barrels and adjusting headspace on Savage centerfire actions thousands of times over the years. I know nothing about FX barrels, but I am curious as to how you are able to rotate the barrel and still have the air port in the breech of the barrel line up with the port in the action. Does that brass piece on the breech end rotate freely on the steel barrel, or is there a full circle chamber around the air port in the breech, or is there something else I am not understanding? All my airguns have barrels that will only work at one position in the receiver.
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Fx liner/barrel is a solid pipe. Unlike other barrel like the benjamin marauder, it doesnt have a transfer port hole. It sit inside a steel sleeve. The brass end have the transfer port hole. You can not rotate it cause it have a grove that will line up with the breach. Since the liner doesn't have a hole, it can be rotate it and poi will change each time you rotate it.
 
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PigeonMan said:
Fx liner/barrel is a solid pipe. Unlike other barrel like the benjamin marauder, it doesnt have a transfer port hole. It sit inside a steel sleeve. The brass end have the transfer port hole. You can not rotate it cause it have a grove that will line up with the breach. Since the liner doesn't have a hole, it can be rotate it and poi will change each time you rotate it.
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Very interesting design. Thanks for the explanation!
 
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