Starting Charge Calculation For a New Rifle

[FishDFly]

Sometimes folks asks where to start with a load.

Bullet diameter cubed X 1502.6 = Bullet weight in grains

Bullet weight (in grains divided 7 X 3 = starting charge

For a .40 rifle

.395 X .395 X .395 X 1502.6 = 92.82 grains

92.82 divided by 7 X 3 = 39.78 grains of powder or 40 grains.

 

[64Springer]

Using the same powder charge volume as your bore diameter is much easier than crunching the numbers.

 

[FishDFly]

Lots of folks post here asking that question, thus the answer.

 

[ADK Bigfoot]

I have never seen this above. If I did my math right, a .62 rifle with a .610 ball would have a starting load of 146 gains. Seems kinda high....

ADK Bigfoot

 

[Idaho Ron]

On 45 and 50 with a conical I start out with 80 gr pyrodex P which is 64.5 actual grains

 

[64Springer]

I have never seen this above. If I did my math right, a .62 rifle with a .610 ball would have a starting load of 146 gains. Seems kinda high....

ADK Bigfoot

I got 146.17

Seems kinda, a lot, high.

Maybe starting with 62 grains of powder by volume for a .62 bore would be safer.

 

[smo]

I have never seen this above. If I did my math right, a .62 rifle with a .610 ball would have a starting load of 146 gains. Seems kinda high....

ADK Bigfoot

I confused too … I came up with.

 

[FishDFly]

For 50 cal. .490 comes to 75 grains.

 

[smo]

120 grains for my .653 bore

Is it the same for fg, ffg , fffg?

 

[FishDFly]

The basis for the formula did not say which powder, for the .62 I would think 2F, not 3F.

 

[64Springer]

Anyone with a Brown Bess and a .73 ball can start with 251 grains of powder.

Pull the trigger and throw the musket at the enemy.

Instant hand grenade.


A .32 squirrel buster using a .31 ball gets 19 grains of powder.

 

[64Springer]

Sometimes folks asks where to start with a load.

Bullet diameter cubed X 1502.6 = Bullet weight in grains

Bullet weight (in grains divided 7 X 3 = starting charge

For a .40 rifle

.395 X .395 X .395 X 1502.6 = 92.82 grains

92.82 divided by 7 X 3 = 39.78 grains of powder or 40 grains.

Where did you find this formula?

Calculating for the bullet weight is correct.

But is seems like something is off with the other parts of the formula.

Thanks.

 

[flconch53]

Sometimes folks asks where to start with a load.

Bullet diameter cubed X 1502.6 = Bullet weight in grains

Bullet weight (in grains divided 7 X 3 = starting charge

For a .40 rifle

.395 X .395 X .395 X 1502.6 = 92.82 grains

92.82 divided by 7 X 3 = 39.78 grains of powder or 40 grains.

Or you could just go with grs of powder to caliber. Don't over think it

 

[64Springer]

Or you could just go with grs of powder to caliber. Don't over think it

Or we could all buy .40 caliber rifles.

 

[Comfortably_Numb]

Ridiculous....

 

[tenngun]

I have never seen this above. If I did my math right, a .62 rifle with a .610 ball would have a starting load of 146 gains. Seems kinda high....

ADK Bigfoot

All the formula I’ve ever seen failed at some point.
Grain per caliber is good, 50 in a .50 is a good start. 35 in a .36 a little heavy. 65 in a sixteen bore a might light.
1/3 ball weight is good, till calibers get too big. Cover the ball with powder works, again till you get too big.
Start light move up

 

[Rich44]

Kind of blew that formula out of the water, or did it just sink at high sea?

 

[Art Caputo]

The easy route…

 

[N.Y. Yankee]

My owners manual says 100gr 2F max for roundball. That's where I start and go down 5 grains at a time.

 

[Johnny Tremain]

The easy route…View attachment 195018

Calculated without barrel length are bogus numbers.
The 45 cal is way under powered for my 42 inch barrel, using the davenport formula the MAX that will burn in my barrel is 75 grains. Above that charts numbers.