See this thread originally was started back in 2006, no matter, if information is good, still good info. You can stuff 60 grains of black powder, preferably FF or FFF in the cylinders of a modern day repo Walker but I've found that 50-52 grains works the best. Larger does such as 60 will not burn completely and has no real performance needs such as trying to down a Mexican or Commanche horse. Try 60 in close to a white paper target or if you live in snow county, fire over new snow. You'll see alot of unburned/partially unburned grains of black. That long barrel on a Walker (or even a Dragoon) isn't long enough to have a complete burn. You're just wasting your powder.
Read an article some years back that FF has a slower pressure curve than FFF and has a 'more harmonious outcome' in large loads such as high 40's and 50 plus grains. Article advised is true to any black powder loadings. I use FF over FFF when reloading 44 Colt and 45 Colt brass cartridges. Have noticed less sharp recoil. Article also showed that using F in large bore cappers such as a Dragoon or Walker (and especially in the Navy and Army calibers) was not recommended and there was no advantage to doing so. I did a test with my Walker and two of my Dragoons comparing FF and FFF and for my style of shooting (alot of point and 25 yards or less) there was no real difference I could see.
Anything less than say 48-50 in a Walker or less than 40-42 grains in a Dragoon is to light (Mouse Faxt, powder puff loads-whatever handle ya want to call em), a waste of time. The Walker/Dragoons were meant for taking authority. I've heard of some guys loading their black powder revolvers heavy for attention at the range, try and see how much shock and awe to impress others or themselves, but those types usually fad away. My 44 caliber 1860 and 1851 get around 30 FFF and my 36 caliber 61 and 51 Navys around 18-20. Use round ball's only. I have tried conical's but they're a pain to get started right and am happy with the rounds. The one guy (nkbj) who posted about using 45 caliber cast bullets for 45's and then sizing the bottom half or so, that is interesting. Might have to try that just to see, I have several 45 ACP molds.