rye whiskey abv increase

[howie]

normally my barrels increase from 65%abv to about 68%abv due to my locality.
this is not a problem in my rum solera system.
however, i have 2 x small barrels of rye whiskey, both stored in the same place, the only difference is a hardwood bung and a cork bung.
the hardwood bung has gone from 65% to 68% as usual, but the cork bung barrel has gone from 65% to 78%
looks like the cork bung is the difference, losing lots more to the angels?
not sure if i should...
1) leave it as it is
2) i could dilute it with water
3) i could add some more rye whiskey at say 55%-60%
i'm not sure if 78%abv will pull the wrong flavours from the barrel?
maybe replace the cork with a hardwood bung?
(it tastes good)

[Ben]

65-78 seems like a lot of climb, is it possible the proof wasn't what you though when you put it in the barrel?

What is the volume loss difference between the two?

My experience has been cork seals better than hardwood in the small barrels. Less volume loss fitted with a cork than with a poplar bung plug. The tiny bung plugs don't have much expansion to seal properly.

[howie]

65-78 seems like a lot of climb, is it possible the proof wasn't what you though when you put it in the barrel?

What is the volume loss difference between the two?

My experience has been cork seals better than hardwood in the small barrels. Less volume loss fitted with a cork than with a poplar bung plug. The tiny bung plugs don't have much expansion to seal properly.

it is possible , but unlikely. i always use the same dilution calculator.
one barrel lost less than 200ml, the 78% barrel lost over a litre (which using reverse calculating is about right in a 6L?)
there are no leaks, i would know if there were, the barrels are kept in individual plastic crates.
at least i'm not losing alcohol