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There's a book by Bryan Litz that covers this (and other things) called "Modern advancements in long range shooting"
Apparently yes there is 5ft/sec in it. In both theoretical and practical testing....

Does it effect wear and total life of the barrel? I know that's not the OP of the thread but i'm looking at replacing my barrel which is 1/8 with a 1/7.5 or 7 to be able to stabilise the longer...

No two 'identical' barrels produce the same velocity either, further skewing any results. Or rather it could be almost impossible to make identical barrels. I reckon this question could only be...