Most guns that I've ever fired always seemed to load and work best with .015 TC factory patches.
I have most all of the common commercially made patch thicknesses, but it seems that 9 times out of 10, the .015 patch fills the bill.
Especially when shooting a round ball that's
.010 under bore diameter.
And I also like to rub a liberal amount of Bore Butter into the patch which much of the excess gets squeezed out at the muzzle during loading.
Having acquired a nearly lifetime supply of unlubed TC .015 factory patches also helped me to maintain using a consistent patch thickness "standard" over many years.
They were probably made by the old Ox-Yoke Originals company which is now Eastern Maine Shooting Supplies.
TC having been located in New Hampshire, that's an assumption on my part due to Maine and NH being neighboring states that share a long common border,
and due to TC's previous home location of Rochester, NH being just a stone's throw away.
But there always seemed to be a lot of similarities between Ox Yoke patches and TC factory patches. --->>>
https://www.emshootingsupplies.com
My guess would be that .015 patches are the most popular patches of modern time, if not all time.