Burnt shredded pieces of patch are very difficult to find.
I tried .015" patches and got just that from my .010" deep .40. Yes - it takes more effort to load a tight patch - oh well. I found I could use the .015" patch with a ball that was .002" larger than than the bore, but a .019" patch was more accurate.
If innacuracy is OK, then by all means use whatever you want, Dennis. Afterall, it's probably a hunting rifle for you, not a trail rifle - if you can hit a 6" circle at 50 yards, it's a 50 yard deer rifle. If you want it to be able to shoot under an inch, you'll need to feed it differently.
Changing light conditions can cause elevation or windage error quite easily. Going from 'mostly shade' to sunny or varrying lighter sky easily causes one to hold more or less front sight - or to one side or the other depending on it's location.
Too, gas blowby reduces velocity, and residual fouling takes up some of that windage from the too-thin patch, producing more, then more velocity as the load gets tighter and tighter shot to shot. The result is usually elevation. some guns shoot lower with more velcity, some shoot higher.
A good smoothbore will shot a 1" group at 25 yards. I suspect a smoothbore with 2 sights would shoot 3/4" down to 1/2" or better. 25 yards is pretty much a waste of time trying to find an accuracy load, but is good for roughing in your sights while checking patches.