Muzzleloader powder charges seem to be all over the board. Published data seems quite low which follows along with smokeless powder. How does one go about developing safe loads for a muzzleloader?

I pretty much follow Lymans black powder load data book...

Max charges? In all my years of ML shooting I never found heavy charges to be the most accurate, and to me accuracy trumps power. (Hint: the deer won't tell the difference. Case in point, the most accurate half-stock rifle I ever owned was an old Ithaca .50 percussion gun. It would put its balls into a ragged hole not much bigger than a single bullet hole at 50 yards all day long, with a charge that many would find to be ludicrously light: 50gr. FFFg. I also killed as many deer with that gun and load as I did with anything else too.)

When I see a guy show up to shoot and he walks around bragging about his 120gr. loads and conical bullets I think "newbie", but sometimes give him the benefit of the doubt if he's prepping for a big bear hunt or aiming to kill a moose (which is never the case).

For 50 cal, ML, 290-300grv bullets, 100 grains seem to be the recommended load. I had a TC Black Diamond that was good for 150 grains, but I have killed a lot of elk with 80 grains of BH209.

For a gun of recent manufacture, I stick with the manufacturer's recommendations. That's what they've pressure tested to. Going beyond that, regardless of whatever logic you apply, seems foolish. Unlike cartridge guns it is pretty hard to pressure test a muzzleloader.

For older guns usually there are some rules of thumb. I tend to push a bit beyond where I want to actually shoot, set the gun up lashed/bungee-d to an old tire, and fire it a few times via a string around the trigger. How many such shots are needed to determine safety? Not sure. Whatever you do is a gamble. As an example, I have a rifle made in 1842 as best I can tell. That suggests flintlock converted to percussion some time in the far past by a gunsmith of unknown skill / competence. I've seen "rule of thumb" suggestions of putting a round ball in your hand and add powder to cover the ball, then pour the powder down the barrel. I've seen rule of thumb suggestions of ratios of ball weight to charge weight. I don't recall for sure but it was something like 7/4 lead to powder. Those two put me around 40 grains plus or minus for my .40 cal (or whatever it is). On the other hand I've seen specific recommendations around 70-75 grains max for a .40. With a gun that old I prefer caution so it mostly just hangs on the wall where shyte doesn't blow up.

Regarding that gun, I have not figured out ideal diameter. It seems to be looser at the muzzle. It's roughly a .40 or slightly below. .395 round balls don't want to go down the barrel. .390 round balls go further but don't quite want to seat on the powder. .385 round balls are friggin' loose even with a thick patch. Someday I may have more time to struggle with it but for now .. it's nice to look at.

What kind of ML and what kind of powder?
Or did I miss that?

CVA Accura MR-X and I've got Tiple 7 and BH209 on hand.

I shoot Goex black and patched roundballs. But a buddy shoots the same CVA, I just texted him asking what he's using with it.

for any and all muzzleloader i shoot, i start with a square load.
50 cal, 50g of fff. that is all i use fffg.
45 cal i start with 45g of fff. etc.
work up and don't be afraid to work down too.
i have 15 muzzle loaders and one wanna be inline. they range from .30 cal to .62 cal
most work best with a square load x 1.5. just my experience.

The manufacturers provide load recommendations and so do the propellant companies. Don’t exceed either. You gain little or nothing by going balls to the wall. Accuracy and bullet choice are important. Many shoot pistol bullets in sabots, but some are too soft for the higher velocities of ML rifles. If you provide more info on what and how you plan to hunt, there is a lot of expertise here you can tap into.

Thanks for the response, folks.

Goal is to hunt elk in Washington (requires open sights, no glass optics). Farthest shot will be in the 200 yard range. So far I have Powerbelt 300 gr ELR, Powerbelt Copper 295 gr, as well as Hornady Bore Driver 290 gr. Open to other bullets, those are just initial purchases. Based on what I've read thus far Powerbelt ELR is a good elk bullet.

With black powder, modern steel barrels wont burn enough powder to case any harm. They just blow unburned powder out of the muzzle. So over loading one is just a waste of powder and there is no benefit in loading max loads. You run into the wall of diminishing returns. It doesn't take a heavy load to kill game. My 50 caliber rifles will exit deer with 60 grains of powder, every time. Accuracy diminishes as you approach maximum loads as well.

When I work up a load for a hunting rifle I start with a "Square" load (50 grains in a 50 caliber) and work up until my groups begin to open up. That's where I stop.

Simple use published data for substitute powders, they are not like old school black powder.

Agree
Most times 80gr volume (not weight) is all we need. Average deer-kill distance nationally remains very close to 100 yards.

Never exceed powder charge numbers in your gun's owners manual. That's your blackpowder church gospel. Not the outside label writings on the powder's dispenser can or package

Why would anyone want to risk finding out?

I prefer weigh all of my charges. I shoot 84 grains weighed of Blackhorn 209 in my T/C Omega. It shoots a touch over an inch MOA at 100 yards with the Barnes T-EZ 250 gr. bullet and a Harvaster Crush Rib sabot. I have an average velocity of 2,136 fps with this setup. The 84 grains weighed is the max charge recommended by Blackhorn. There are some muzzleloaders out there that will take a bigger charge than 84 grains. The CVA Paramount is the only one I know of but there may be more.

Was a high schooler when I bought a .50 T/C Hawken.
Heard lots of stuff about blowing up, or not blowing up muzzle loaders.
"Can't burn enough Black to hurt them, 2 balls, 3...."

So, I tried!
200, 300 grains of 3F? It kicked a little harder.
2, 3 balls? It kicked harder.
Double charge and 2 balls? Kicked.
Stopped there. Wasn't trying to build a bomb!

My "first" test shots were fired holding the gun over a log pile with the stock against
a log. After 1, they were fired normally.


Everyone seemed to agree that a gap between powder and ball was the most likely
way to blow one up, so I never tried that.


Always ised 90gr FFF for hunting.
My eyes don't see open sights real well, and I'm not the best Flintlock shooter.
Could hit stuff out there, killed deer.
Guess it was Bubba Stylin' the 19th Century!

I watched a couple guys at the range increasing powder charge with each shot, shooting thru a chrono. I think they used Pyrodex, and were shooting .50 cal with buffalo type bullets maybe 300 grain. Any how, velocity increased a little with each shot, from 60 grains up to about 90, then stayed at 1800 fps all the way thru 120 grains. They concluded 80 grains was good enough. Then they got out a Win 1886 in 45-70 and said it kicked too much and would I like to buy it for 300 dollars. I still kick myself for not grabbing it.

I sold an 86 30 years ago for 3500.00. if i had passed on one for 300.00 i think i would seriously consider seeing a shrink!

RB - charge = caliber
Conical = caliber + 40%

Both by volume, not weight.