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Old 4th November 2014, 08:26 PM
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Brian.Samson Brian.Samson is offline
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Join Date: Jun 2009
Member of: Pontefract, Doncaster Airgun Range
Location: Doncaster
Posts: 2,324

Originally Posted by flyfisher View Post
In my eyes, the only valid reasons for not using "heavy" for the FT would be that their manufacturing quality is worse or that their balistic coefficient would be less than 0.0235.
Manufacturing quality isn't the only factor that has an effect on BC.

Here's an example for you - you can take a single tin of pellets

Fire 10 shots over a downrange chrono in one rifle, Fire 10 shots over the same chrono at the same muzzle velocity but in a different rifle and end up with 2 different average BC's for the same pellet.

Something to consider... pellets don't come out of the barrel the same shape as they went into the barrel. rifling, air delivery, twist rate, choke etc etc etc can and do all have a significant effect on BC.

I have two different batches of JSB 8.4's here - one gave a BC of 0.022 at 50m and the other tin gave a BC of 0.026-0.027 - outwardly the pellets look the same with no obvious manufacturing defects.

And that's my point...

With 8.4's you have 50 different dies and 3 different head sizes to choose from
With 10.3's you have perhaps 10 dies and 1 head size - 4.52
You have suspect quoted BC values from an unknown origin you are using for your on paper comparison.

So... in summary - on paper using suspect inputs, there may be an advantage with 10.3's
In the real world in your rifle there may not be, and the chances are that with 8.4's you have better odds of finding a better barrel match than you do with 10.3's. (50 batches vs 10 batches)

However - If you manage to find a 10.3 batch that groups well in your rifle and has a high BC, then theoretically that's a good choice in pellet.
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