I read an article that compared velocity -vs- barrel-cylinder gap several years ago but can't find it right now. As I recall there was less difference than you'd think between a tight gap & a wide gap.
And that test was on the same gun (Dan Wesson, IIRC). You're comparing two different revolvers. It's widely acknowledged that two revolvers that are the same model, cartridge, ammo, & barrel length will not produce the same velocities. (Reference Speer #9: Why Ballisticians Get Gray!)
There maybe 100-200fps difference between two "identical" revolvers. Barrel-cylinder gap is not the only factor that affects muzzle velocity. Even if you knew definitively what difference the B-C gap "
could" make, comparing your two guns wouldn't take into account all other factors that could be affecting the MV differences.
I don't think I'd lose any sleep over it until it exhibits other problems like excessive lead/debris spitting.
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PS: Here's the link to the web page
skipnsb mentioned:
BBTI - Ballistics by the Inch :: Cylinder Gap
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