Working up a load

[tsmgguy]

One of the experts at our local range (we have many) shared his rule of thumb for working up initial black powder loads. He said that a nice comfortable short range target load would be the same number of grains of ffg as the rifle's caliber. In the case of my Baker, 62 grains for .62 caliber. He then said that a good full charge for hunting would be the rifle's caliber times 1.5. Again, for the Baker, about 93 grains. He said that this is a good place to start for any muzzle loader.

I've read that the British used 90 grains in their Baker Napoleanic War era cartridges, so this would seem to fit.

What say you all?

 

[paulvallandigham]

All these " rules of thumb" are interesting, and as long as you are using BLACK POWDER you are not going to be far wrong. The caliber size, and 1.5 caliber size rule has been around for many years. It works in some calibers, and not so well in others.

I don't think you need 90 grains of 3Fg powder behind a PRB in a .62 cal rifle to kill anything, short of Cape buffalo, or Elephant. Depending on stock design, recoil at those loads can be substantial, or " manageable".( At the top of the index to this forum under Member Resources, I have an article I wrote on how to handle Heavy recoiling guns.)

There are folks here who will swear by loads that use a lot more powder than the formula suggests, on the other hand. I always ask them if they have ever done any comparison testing with those heavy powder charges.

With the .62, you have to remember that you are sending a ball that weighs 3/4 oz. down range, at that within 100 yards, its a regular Freight Car coming at you. Rarely is any such ball recovered inside the animal's carcass. Its the weight of the ball that controls depth of penetration, NOT Muzzle Velocity.

A friend used his .62 cal. rifle to shoot a 200 lb.+ Wild Boar in the front of the chest at about 20 feet. The ball went completely through the Boar, being found under the skin in the opposite side rear ham. It had penetrated lungs, heart, liver, kidneys, stomach, and intestines along its path. Penetration( primary wound channel) was in excess of 30 inches. I believe he used a load of 80 grains of 2Fg powder.

 

[MikeChapin]

I use the caliber as a starting point when I am working up a load. I go up and down with charge to find the load that gives the best groups at 50 yards. Whatever it is it will give me my 25 and 50 yard target load. For a 100 yard and hunting load, I start at about 1.5 and adjust from there until I am hitting at 100 yards with the same sight picture I was using at 50 yards.

The charge depends upon patch/ball used with the load. Last month I was trying out a .520 ball with a denim patch in my Santa Fe. I wanted to use the .520 ball instead of the .515 I use because the .520 mold is a double cavity and the .515 is a single.

I benched it using the 50 grains I use with the .515 ball. The group was terrible - a good six inches sprayed on the target. It was bad enough that I was wondering if I could still shoot from a bench. I fired 5 more shots using the .515 balls and they could be covered with a fifty cent piece. I checked the patches I was using on the .520s but they were fine.

The weather was getting iffy at the time so I packed up and went home. It looks like this rifle is going to need a full workup for the .520 balls.

My .58 comes pretty close to the rule. I use 60 grains for 25 and 50 yards with 85 grains for 100 yards and hunting. As for hunting a .570 ball with 85 grains will go through an elk's chest at 70 yard with no problem.

 

[tsmgguy]

Many thanks, Gents! It does sound as though this 1.0/1.5 rule of thumb might be a good starting point, but a starting point only.

I know for a fact that the Baker with 90 grs. of Ffg is a brutal kicker, and is (for a given ball/patch combination) far less accurate on the bench than lighter loads of 60-65 grs.

There's anecdotal evidence to suggest the Baker armed British troops would often try to pour out part of the powder charge, just to spared the recoil! I can understand why.

We have Javelina in our part of the country. I'd not hunt them with a flintlock as I've had the value of follow up shots demonstrated to me too many times!

 

[renovato]

That rule of thumb mirrors my own experiences pretty well. I had always started with a powder charge the same as the caliber and worked up 5 grains at a time. I would find a weight near my starting load that always grouped well. Then as I worked up, I'd end up finding another "sweet spot" in the 1.5 range and use that as a hunting load. Some guns keep a pretty regular group during load workup and some show distinct sweet spots. Why this is, I couldn't tell you.

I had always figured on twice the caliber as an absolute maximum load, though I have never had any of my guns group as well when loaded that hot.

 

[hanshi]

I also agree that the formula works out okay, for the most part. I say for the most part because it starts to fall apart just a bit when you get out of the mid caliber range. Say from about .40 - .60, give or take, is where it applies best. For instance starting a .32 at 32 grains & going up to 48 grains is missing the point. The best .32 loads seem to be in the 15 - 30 grain range.

 

[tsmgguy]

Agreed. I doubt that I could cram 45 grs. of black powder into each chamber of my Colt's M1860 pistol!

 

[paulvallandigham]

The " Rule of Thumb" was intended for rifles, only. Not handguns. The sub-calibers are one area where the formula fails, and the very large calibers are the other. If you are shooting .40, .45,.50, and maybe .54, the "formula " works sorta.

 

[Lostrifle]

I've read that the British used 90 grains in their Baker Napoleanic War era cartridges, so this would seem to fit.

Remember that the British used some of the powder in the cartridge to prime the weapon.

 

[paulvallandigham]

Also remember that the quality of the powder was not on par with what we use today. To get close, you need to use Fg powder sold today.