What granulation?

[tg]

My point was that in many guns the complete burn may be happening after the ball has left the bore, this is where a chrono would help determine when enough is enough and the energy with 70 gr. at 50 yds should do as well as the energy of 120 gr at 100+yds. Each gun and situation is different but I think many are "wasting" powder which is a choice that is a given right.

 

[Ohio Joe]

I agree tg,
You only gain about 37 Ft-lb of energy between the two loads at 70grns/50yds, and 120grns/100yds, according to Lyman's Black Powder Handbook. Not really enough to justify 50 more grains of powder from what I see... Where you lose is in drop at 100 yards if you need to take the shot from that distance with only 70 grains. 70grns @ 100 yds - drop 12.77 inches... 120grns @ 100 yds - drop 7.08 inches... Of course the opposite is true too, 120grns @ 50 yds - 1.43 inches of drop.
I know what works for me when hunting with my .54; 90grns @ 50 yds - 756 Ft-lb of energy, 2.03 inches of drop... 90 grns @ 100 yds - 490 Ft-lb of energy, 10 inches of drop...
These are based on a .535 roundball load, using 3fg... I prefer a .530 roundball, using 2fg, so my energy would be different, but I doubt enough to make any real difference in the figures above...

 

[Herb]

tg- No, 120 gr of powder in a .54 ain't passing the point of diminishing returns. But more powder kicks a lot more, and there isn't much practical gain at ML ranges, say 100-125 yards. To put this in perspective- Lyman Black Powder Handbook, 1975, shows loads for a 30" .54 cal test gun. Top load was 160 grains of 3F G-O powder with a patched .535 ball for 2,072 fps at 14,710 CUP (pressure). A 43" barrel gave 2,158 fps at 15,000 CUP.***Lyman BP Handbook & Loading Manual 2nd Ed, 2001, shows a .54 cal. barrel 32", 1/60 twist with a .535 ball and a max load of 120 gr Goes 3F at 1735 fps and 8300 psi AND a max of 120 gr Goex 2F at 1803 fps and 8300 psi. Of 193 .54 cal combinations of different barrels, powders and projectiles, 56 have maximums between 17,000 and 29,100 psi.*** The original Green River Rifle Works 1978 price list recommended their barrels be PROOFED with a single patched round ball and 2F powder. Charge for .54 caliber was to be 210 grains. Then the recommended MAXIMUM LOAD was 175 grains of 2F, to give about 2,000 fps. Note that this was their barrels, no longer available. Even Dr. Gary White, who owned the business, used only 150 gr of C&H black powder and a .526 ball at 1860 fps in a Leman Trade Rifle to hunt Dall sheep. Shot one in the neck at 50 yards and it ran off. Had to chase it and shoot it in the lungs at 150 yards to kill it.***The max load for .45 cal was 110 gr 2F, for .50 cal 150 gr, for .58 cal 200 gr, .62 cal 260 gr and .69 cal 300 gr, all to give about 2000 fps. I remember one GRRW employee at a match, shooting a .69 GR Hawken. Don't know what his load was, but the recoil turned him half around. Don't remember he ever hit anything. I was tied with Doc White in the finals of this match, using 35 gr 3F in my .45 Leman Trade Rifle. When we got to 200 yards, I doubled to 70 grains, didn't know the drop, and somebody beat us both.*** I'll come back later and give some of my test results.

 

[Stumpkiller]

I used to shoot 120 gr of FFg in my .54 when I was young and exhuberant. Now I shoot 90 gr, or 42 gr squirrel loads. I just don't need that much energy to nail a whitetail.

Something I haven't seen mentioned here. FFFg is not more energetic than FFg by weight. It is smaller in granulation size, so a given volume holds more. That is, a powder measure that holds 70 gr of FFg will hold about 75 gr of FFFg because there is less trapped air between the grains.

 

[tg]

I think in a sense with the shorter barrel you have passed the PODR as you have gained velocoty with the longer barrel with the same charge, that was where I was going...particularly with all the 28" barrels around....if the same load in a 42" barrel hase higher press/velocity then the shorter barrel cannot utilize that load to the max.

 

[sse]

It is smaller in granulation size, so a given volume holds more. That is, a powder measure that holds 70 gr of FFg will hold about 75 gr of FFFg because there is less trapped air between the grains.

This reminds me of a squib in one of the supply catalogues that said the powder measure advertised was calibrated for FFg. Which got me to scratchin the noggin. ::

Regards, sse

 

[roundball]

I think Stumpy is trying to say that the same 70grn by "volume" measure, would throw a "heavier" weighed charge of FFFg than FFg, due to the FFFg being smaller, less air spaces, more powder in the same physical space of the measure, etc.

 

[shmrck1]

Huntin
i have always used 3f in my .45 and under and 2f on .50 and above,but that just a personal choice. i have tinkered
around with other loads but this seems to work for me.
of course as we all know every gun is different.
I am snake-eyes

 

[bob1961]

i've started out with 3f and thought that was right....no problems so far.............................bob

 

Dave - I've yet to see a .50 or larger that didn't improve it's accuracy with a proper load of 2F over the best it would do with 3F. It's possible such a rifle is out there, but in 35 years of shooting BP, I've not seen one.
: 2f will give the same velocity as 3F "at it's max pressure for the rifle", but with lower pressures than 3F. This makes it easier on the patch & lube requirements. As far as fouling, a max load of 3F for the gun (for example, 15,000LUP as quoted by Lyman for most barrels) 3F actually seems to make MORE fouling than 2F at the same velocity. This could be due to being harder on the patch and lube due to it's increased pressure.