As long as you don't pour the powder down the barrel with the barrel vertical, so the barrel becomes a drop tube, the powder is not going to " compress ". I "Feel" my ball crunch powder when I seat it the first time I am working up a load, and then mark my range rod so I load to the mark thereafter. I do not leave an air space between the powder and the PRB. However, I don't try to compress the ball or seat it " firmly " as I used to do with my percussion guns. The Chronograph indicates that my " touch the powder " technique gives a small SDV, although velocity is a little less. The velocity issue can be solved by adding a few more grains of powder to the charge.
With percussion ignition, Use FFFg powder, and hold the barrel vertical when you pour the powder in the muzzle. That makes the barrel a " drop tube", so that gravity compresses and packs the powder together. With percussion caps, and that semi-closed ignition chamber, flame is actually INJECTED into the compacted powder, to ignite the powder quickly. That is as it should be for consistent burning, and pressure build-up, before the PRB begins moving forward.
Again, as with Flintlocks, most percussion calibers are aided with the use of either an OP Wad or Filler, as they not only seal the gases, but they delay the movement of the PRB foreward for a few millicesconds, and that allows the pressure to build higher, and the temperature to build up so that the powder burns completely leaving very little residue.
As your caliber increases in diameter, the weight of the ball also increases, and the need for a OP Wad or filler to create consistent velocities seems to lessen. I am still working with my .62 caliber smoothbore, and I have not yet done the before and after testing with OP wads, or fillers, and just a PRB. I have a gunsmith friend who owns a .62 cal. rifle, so I want to see what difference are occuring with the rifle vs. smoothbore, too.
In small caliber flintlocks, (.40 and smaller) you use much less powder, but the size of the chamber behind the ball is made less by both the smaller powder charge, AND the caliber. I find using FFFg powder in these guns either flint or percussion, to work just fine, but using an OP Wad does benefit consistent velocity production here even more so than in the middle calibers(.45,.50 & .54). That is because the weight of the ball being fired is so small, it offers little resistance to the building pressure, especially in percussion guns, where the percussion cap alone is sufficient to move the ball up the barrel.
You do need to use a chronograph to learn these things, and if you are not a target shooter, you won't get the benefit of all of them. I followed all kinds of " rules of Thumb" before I owned a chronograph, and even then, did not begin to use the Chronograph to challenge long-used practices until I stumbled onto differences in performance based on changing one thing or another. My brother has been using his chronograph extensively when shooting his .40 caliber rifles( and a .28 caliber gun!), and that is what alerted me to differences with smaller caliber rifles.
However, the changes in how you load your gun will help you in both getting that Ball where you want it to go on that rare long shot while hunting, and the benefits for cleaning the gun are worth the effort. YOu have enough problems just trying to adjust your cleaning process to the weather ( Temperature and Humidity) depending on where you live, and where you shoot, and what God has decided to visit upon you on a given day. And, what works when you load the gun at dawn may not do so well at Noon!
When the switch was made from Black Powder, to Smokeless powder, people thought, " Now, we have a One size fits all ", situation with firearms, and we won't have to spend so much time cleaning guns to keep them shooting accurately.
Wrong!
Tell that to the veterans of the Early years in Vietnam, when the new M-16s were not even provided with cleaning kits, and the powder used in the new cartridges in the chambers that were NOT chromed, were causing the guns to jam in the middle of firefights.
My point is that mankind has been seeking that KISS solution to making guns shoot since the first gun was made, and things haven't changed. Part of the deal with shooting traditional rifles is learning how to keep them functioning in all kinds of weather.
The stuff I am discussing here is what I think of as " Set-up" issues,- choice of powder, choice of OP Wad, or loose filler, choice of ball diameter for a given caliber and dimension, choice of patch thickness to use with that diameter ball, and choice of lube to use. Once those decisions are made, you forget about them. Its not something you have to do every time you go shooting.( When you get older, it helps if you write down the powder charge, ball diameter, patch thickness, lube choice, etc. for each of your guns, so you don't have to re-invent the wheel when you shoot a gun for the first time, 5 or 10 years after you last shot it!)
I am always looking for, and reading my patches, after each shot- a habit from the days when I didn't have a chronograph. I look for them in the woods when I shoot a deer, too. I read those spent patches, and put them in a pocket to take the trash out of the woods, or off the range.
I read the cleaning patches I use to tell me how wet or dry the barrel and residue is, so I can adjust my cleaning procedures a bit.
I pay attention to wind direction, temperature, and relative humidity- now based on those cleaning patches and how slick and damp the residue appears, and feels to my fingers when I pull that first cleaning patch out the barrel. Watching the Wind direction is a habit I have used for years hunting, but here in the Midwest- a change from the prevailing wind direction for a given time of year tells me that the weather is going to change- getting either wetter, or dryer( and colder).
Since MLer shooting is basically a one shot deal, these changes in loading and cleaning procedures that require a bit more time to do are NO handicap. That seems to be the hardest adjustment for new MLers to make when they have prior experience with Breechloaders, only.
It seems everyone wants to find a way to shoot a second shot faster. I was there, too, until I watched one of our club members shooting a Leonard Day Swivel Breech rifle, and watched my pocket watch to see how fast he got the second barrel turned, and the shot fired. He was only a bit faster than some of the members who were loading using premeasured charges and a Ball block.
When I was deer hunting in a treestand the next Fall, I use my watch to time the movement of deer who were within sight, but behind too much brush to get a clean shot, and found that even browsing, most deer would be gone before even that swivel breech rifle could give a second shot.
Once you have crossed into the Dark Side of Flintock shooting, IMHO, you have accepted all the challenges BP shooting has to offer. You understand that this is a One Shot, One Kill hunting sport, and that "speed of loading" and firing is not used in the same sentence as Flintlock.
Yes, you can surprise each other with how fast you can load the rifle( especially using a bare ball), and get it to fire, but you probably won't be surprising anyone with how accurate a long range shot you can make loading your gun fast.
