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thimbles for barrels and do they work

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A

aa_limited

Member
Jan 27, 2016
1,229
36
ontiaro, Canada
hey guys do you find your air gun barrels work? rwa is a good example they offer the bm500 with a thimble now.
​as well I know of some custom makers will do a thimble as well for your gun.

​do any of you guys use a thimble on your rifle and if so how do you find them.
​do you find rotating the barrel improves accuracy with all pellets to a degree
​or do you find they help all pellets shoot more accurately to a degree.
 
Turns out that even for the most precise barrels, the bore is not exactly aligned with the barrel's outside surface. Also, there may be a slight curve to the bore - an arc rather than a straight line. Therefore if you were to lock down the gun and rotate the barrel, POI would rotate around a circle like hours on a clock.

Some shooters believe that barrels shoot best at 12 o'clock or 6 o'clock because of resonation/harmonic patterns. Also, 12 o'clock can help with scope alignment. Finding the ideal rotation is called indexing.

Thomas air rifles are made so the barrel can be rotated by the user, though Mike pre-indexes the barrel. RAW and others use a transfer port, so indexing requires an adapter. The adapter (thimble) keeps the transfer port aligned while allowing barrel rotation.
 
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aa I am glad to see you started this thread. I learned about indexing 40 + yrs ago, when my gunsmithing bud was setting up my 6.5mm long range (500-1000 yard) rifle. I had no idea that this technique was being applied to air rifles. It did make a major difference in my rifle back then. I know there will be the experts wannbee or real who say it does not make a difference. I personally would disagree. I cannot see any air rifle company going to the expense or using the type materials it takes to even make a bbl that is 1/1000 true even 3/1000 which is rather rare even with the top dollar pb rifles. I am getting ready to purchase a rifle for FT competition and would like to know of a source to get a thimble installed on it.
 
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indexing does 3 things
​
​1 it helps with the set up of the scope. windage left and right and your poa going to the left and right of your zero at any other range other than your zero range.
​2. it helps with tuning the barrel.
​3 it helps your from not maxing out its elevation turrets in the scope when set at the 12 oclock position.

​I feel I made the best and most knowledgeable air gun purchase of my life ,
I feel it has the potential to be one of the most accurate air guns out there,
​I'm getting a raw 500bm action with thimble set in a l r t stock.
​it will be about 4 months or so till its in my hands but iit will be worth the wait... I'm sure of it
 
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Guys tks y'all, so much to learn yet and I love it :) AA it looks like you are like me in making sure to know what I am getting and what the expectations should be. Well done brother and you are dead on about what indexing does regardless of what type of shooting discipline it is. In long range shooting if you had a bbl that was indexed at 3 or 9 oclock then along with wind drift you had to factor in that indexing too. That was a real PITA ! I can very clearly see the advantage to doing this with an air rifle. I would think that air rifles would benefit even more than a PB rifle.
 
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