As I while the time away waiting for warm weather to return, I am thinking of p.p. for an original .40-70 Ballard using black.  The only other caliber I have p.p. was the .22..the .40 is alot easier!  But I had trouble with fliers..my thinking was patch must seperate from bullet at nearly the same instant as it's other group members...and wet patching results in a very tight fitting patch.  so tight the patch must be destroyed in trying to remove.  So, my thinking now is trying to use a dry patch.  So far, I have been using gage pins to determine dia. over patch with various paper thickness.  Dry patching is alot harder than wet..have to pull harder & hold to keep tension.  It seems I will have to have cases charged, wads including lube wad if used..all set to go & seat bullet in case mouth with twist motion in order to prevent unraveling.  The dry patch should in theory anyway leave bullet more positively than the wet.  What do you experts think?  Has anyone tried this?

22-5-40,
It's combination of what works for you and what doesn't. The rifling also has a bearing on the matter. Many rifles have grooves 5-6 thou' deep others like precision target rifles may only have grooves  2-3 thou' deep. Providing the bullet is large enough and soft enough to bump up on firing, the lands should cut through the paper patch so that it separates in the first few inches of free flight. Failure to separate may not mean much if your hunting in timber, but if you shooting at 1,000 yards range at targets, the accuracy will be terrible even assuming you get everything else right. 
The Sharps Rifle Company used to paper patch bullets by the thousands each day and employed a large number of girls to do the patching by hand. Later Hugo Borchardt designed a machine to do it. This machine had a paper patch magazine which was spring loaded and presented each new patch in front of a low powered jet of steam. The speed that the machine worked at meant the individual patch was barely moistened before it was used, this moisture slightly shrank the patch after it was applied and dried, so it was a tight fit. Lube was invariably put beneath the bullet in-between two card wads. All Sharps ammo was made like that and so was all of the ammunition supplied to the British Army and Empire troops in tens of millions. 
All PP bullets should be smooth sided without grease grooves, the latter just slow the bullet down faster at longer ranges. Grease on the patch will not help with patch separation at all, it may even make it stick harder to the bullet. I am aware that some PP ammo has been found that looks as if the patch is greased or oiled. I would suggest that this was likely applied later by accident or design by individual shooters, an oiled, waxed or greased patch will pick up dirt and other muck over time and that won't do any good at all to a rifle barrel. 
In the end, you pays your money and takes your chances. Experiment, see what works for you.

Harry.

I wet patch but will be experimenting with dry patching a bit this year.  Brent Danielson dry patches and has been doing quite well these last few years.  I find it a bit more fiddly, but like the idea.  I have no issues with patches not coming off at the muzzle when patching wet though.  Generally they are shredded like confetti.   

Chris.

.22-5-40,

If you have difficulty taking the paper off of a wet-patched bullet, you need a different paper.  My wet-patched bullets will shed the paper easily if handled too much.

Keep on hav'n fun!
MikeT