Crown barrel indexing?

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AirSupply

AirSupply

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Jan 12, 2017
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Victoria, Australia
There are differing views on barrel indexing. Some manufacturers design there guns to make it possible to index the barrel and some shooters specifically ask for thimbles to be fitted to make indexing possible. 
Others don't think it's worth it. 
For those who don't know what it is 
It is the ability to turn the barrel in the block of the gun. 
Why? 
Because no barrels are dead straight. If you shoot at a target and can turn the barrel between shots you'll end up with a circle. 
Theory is if you position the barrel at 12 or 6 o'clock on the circle you can eliminate some horizontal dispersion at different ranges. 
What I'm asking is can you index the barrel liner on the smooth x barrels. That is can you turn the liner inside the outer barrel the same way you would do with a thimble? Would it work the same way?
Michael
 
IMO the ability to vertically index your barrel is very important for long distance shooting. 

Thats a wonderful question & I'll have to pull my liner out & check. The reason you cannot (easily) index most smooth twist barrels is because the transfer port is drilled into the brass adapter which is glued in place. I can't imagine the ST liner goes back that far. So I think you might be right. Thats an intriguing question & I must know the answer.
 
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he is talking about barrels shooting left right, not vertical up and down.
The liner is symmetric tube so it will rotate freely so i am sure you can put a mark on it and turn. The o rings are a bit weird -to me-but i guess the liner must be fixed at both ends.
Ideally they should be making barrels which shoot straight right, with no need for indexing.
it would be interesting if someone did an experiment on a full rotation, to see how big diameter the POI circle is
indexing is masking a problem actually. bending the barrel back would be the definitive solution
 
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indexing serves more of a purpose than just the scope being in line with the barrel. if there is a thimble used.
​it also makes the pellet go straight into the barrel too. I have seen smaller groups when the barrel was rotated in the desired degree with different types of pellets. its a fact. cuz ive have been experimenting with thimbles in air guns. and thimbles do work
 
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"aa_limited"indexing serves more of a purpose than just the scope being in line with the barrel. if there is a thimble used.
​it also makes the pellet go straight into the barrel too. I have seen smaller groups when the barrel was rotated in the desired degree with different types of pellets. its a fact. cuz ive have been experimenting with thimbles in air guns. and thimbles do work
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if you have a bent Crown barrel, it will remain still bent no matter how you spin its liner in it. I dont think you understand. the HW100 is different, you spin the whole barrel, and the pellet enters the barrel directly differently. I still believe if you have issues at bore out of axis/misalignement at breech end. you should send the barrel back as it is defect.

pellets spiral out of barrels when fired, but when the barrel is not aligned with the action (on the action the scope sits right. not on the barrel) by adjsuting the scope turrets you achieve nothing. so thats why you need to work with mainly the barrel. 
liner is just spinning in the outer barrel. 
it is just another variable.

imagine your barrel is pointing badly to right shooting off axis (from the ideal perfect one) then you spin the liner in it.
you will probably find the POIs will describe another off centre circle right there off axis.
maybe you can use both to cancel each other out. good luck with that
 
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"AirSupply"
What I'm asking is can you index the barrel liner on the smooth x barrels. That is can you turn the liner inside the outer barrel the same way you would do with a thimble? Would it work the same way?
Michael
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Yes Michael, the liner can be indexed in the Crown.
I have indexed numerous barrels over the years.
At just 25 yards the only one I have tested that made a less than half inch rotation circle was a Benchmark tight rimfire barrel I bought from Dan Brown for my FX Elite. It is an excellent .22 barrel .
Most others described arcs from an inch to three or more inches at that range. 
Regards, Harry. (Just for you - the experiment was successful and the results are stunning - but not ready to go public yet). Again, many thanks for your kind offer.

 
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Hi Harry, It did look like it would work from videos and pictures I'd seen. Will have to have a way of marking them so they can always be put back indexed correctly. If changing liners an indexing mark will also make it easier to zero the scope if a record of the adjustments is kept. 
Im sure you have it all sorted!
Great news things worked out. 
Don't forget I have a tin of Mk11 pellets with your name on them if you'd like to try them. 
Looking forward to hearing more. 
Michael

 
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The title says Crown barrel indexing. not liner indexing.

to index a proper barrel you do this
https://www.pimpmyairgun.com/viewtopic.php?t=1441

if you turn the liner, it will not index the barrel, these are related but not identical things.
if the barrel is pointing the wrong direction, no matter what you do to the inner liner, it wont shoot straight it will still shoot where the barrel points at.


for those who gave me the neg accuracy points, you'd better prove me wrong on this.
 
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"sirk"The title says Crown barrel indexing. not liner indexing.

to index a proper barrel you do this
https://www.pimpmyairgun.com/viewtopic.php?t=1441

if you turn the liner, it will not index the barrel, these are related but not identical things.
if the barrel is pointing the wrong direction, no matter what you do to the inner liner, it wont shoot straight it will still shoot where the barrel points at.


for those who gave me the neg accuracy points, you'd better prove me wrong on this.
Click to expand...
For the record, I for one did not give sirk a negative accuracy point. I have never given anyone negative points.

When my Crown replacement barrel unit arrives, I will be happy to take up the challenge to research this concept and I have noted sirk's point of view. Regards, Harry.
 
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He's an opinion from a newbie to this. After about 1500 rounds through my FX Wildcat MK II Compact poi started to open a little. Figured it was time to clean. Cleaned everything and re assembled just like when I installed the smooth twist x the 1st time. No where did it say to index. Everything ready 1st mag @ 50' about 3" to the right and loose grouping. Kept shooting and re-zeroing. Finally back to center. shooting ok. Prior to cleaning I could go 6 mils and a small line up and be dead on at 75. 16 or so up and be on at 100'. Set it at this have no idea where the rounds went. Started holdover and adjusting turret long story short almost out of up on turret at 75' Realized then there had to be something with the barrel after cleaning. Obviously found this topic here. Next step shoot rotate and to fine tune top center. Luckily with the Wildcat smooth twist barrel liners no ports to worry about. Evidently on initial assembly of the smooth twist X I came pretty close to top center accidentally and then lost it when cleaning. From now on the barrel will be cleaned without removal or at the least with index marks before removing. FX really needs to have this mentioned somewhere in its manuals. . Live and learn (Actually read live read and learn.)
 
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