Make the crown look like this, and heavily patched balls are easier to seat into the muzzle and easier to push down as well.
Make sure you are using enough lube. Some folks skimp on the lubricant.
You can make your muzzle look like these by using the end of your thumb & rotating it with emery or wet/dry 320 grit in the muzzle
as shown in the last picture. 15 minutes or less. Push a patch down an inch or so, then after finished, retrieve it with tweezers or needle nose pliers.
If the boe is smooth, loading is easy. If the crown is smooth, not just factory cut with a tool, seating the patch and ball into the muzzle, is also easy.
Just a smack of the hand on the starter knob and it's done.
The only thing a thinner patch will do, is decrease accuracy and reduce the bore cleaning that happens with a good thick patch. Every time I own, shoots
well with a 10 ounce denim patch. Same patch in every one. .682" ball in the .69, .495" ball in the .50, .350" ball in the .36", .596" ball in the .62 smoothbore.