IMO, there is no reason not to...and speaking only for myself, I pay no attention trying to correlate a ML smoothbore load to any modern load...apples and oranges as far as I'm concerned...its a sturdy steel pipe...as long as normal pressures/safety issues are considered, I load what works best for a given situation regardless of what anybody else does or believes.
I copied this individual's turkey load in my .62cal and its been outstanding for me:
http://members.aye.net/~bspen/SmoothboreLoads.htmlAlso, speaking only for myself, I pay no attention to references of 'square loads'...ie: "if they're not square loads the loads aren't effective because they'll have longer shot strings for the given gauge diameter and that will automatically create holes in patterns."
However, I look at the excellent performance of a .410 shell with its 1/2oz and see that its matched by its big brother the 3" shell with 11/16oz load...both outstanding performers on my skeet range...no apparent problems with the length of the shot strings or holes on patterns...outstanding on a dove field too.
And consider the .12ga...while its .12ga diameter remains fixed the common set of offerings from every big name shot shell manufacturer contains larger and larger size shot charges in 1/8oz increments all the way up to 2+1/2oz...apparently no worries about long shot strings or holes in patterns there either, whether after turkey, crows, doves, ducks, geese, etc.
So personally, while being safe, I live by the old adage:
"little powder, more lead, shoots far, kills dead"
Other's mileage may vary and that's fine...