50 cal ball speed

[mjm46@bellsouth.net]

In my .50 cal rifles I've been using 80 Grains of 3f powder just because it felt right and shot well never actuall knew the ball speed. Yesterday I had the opportunity to shoot through a chronograf. My barrel is a 44" .50 cal Rice barrel shooting a .490 ball patched with .020 lubed with Hoppes 9 + and it chronographed at 1766 FPS. I had estimated from seeing examples that I was up there maybe about 1600 or a little more. In general I am pleased.

[Daryl]

My .40 and .45 guns like a speed of just over 2,200fps when using Hoppe's or LHV/Shenendoah lubes. With spit or alcohol/water lubes, they'll shoot down to 1,600 to 1,700fps very accurately.  They want more powder for the slippery lubes. The .40 has a 48" twist and the .45, a 60", so rotational rate has less to do with it, than we thought - perhaps, as both rates of twist shoot well with identical velocities, yet have very different twists.

[northmn]

I chronographed my 50 with a 36 inch barrel and got over 1800 with 80 grains of GOEX 3f.  I have used as high as 90 grains but found the 80 grains to be very close in velocity.  Mine was a percussion rilfe.

DP

[hanshi]

In my .50 DeerHunter with a 24" barrel 100 grains gave around 1720fps.  The same load in my .50 Va rifle with 42" barrel it gave well over 2000fps.

[Daryl]

I found this data from my 22" .50 cal barrel on the Canoe gun I purchased a number of years ago.

Lube was Leehigh Valley Lube.  .495" Ohause mould pure lead ball, using .021" ticking - Bauska barrel, I was told.

70gr. 3F GOEX- 1,800fps, 1,796fps, 1,799fps, 1,806fps, 1,801fps - 7fps spread on 5 shots - pretty close.
80gr. 3f GOEX- 1,963fps, 1,955fps, 1,963fps, 1,960fps, 1,961fps -  8 fps spread on 5 shots - again, close.

[Leatherbark]

About 5 years ago I chronographed a Blue Ridge flintlock in .50 caliber. With 80 gr of 3
f Goex I was getting 1700 or so FPS. With 80 gr of Swiss it was doing over 1900 fps. Swiss was definitely hotter thats for sure.

Bob

[Daryl]

Interesting - makes me wonder why that 20" barrel beat the longer ones with 3F - GOEX.  It wasn't a chronograph error as I double check with 2 of them, giving no more than 4fps difference, shot to shot, ones screens placed in front of the other.

Ball fit as well as lube and barrel interior condition probably makes a difference as well. These three things could easily  make shorter barrels faster than much longer ones.

[Dr. Tim-Boone]

In my .50 DeerHunter with a 24" barrel 100 grains gave around 1720fps.  The same load in my .50 Va rifle with 42" barrel it gave well over 2000fps.

Interesting - makes me wonder why that 20" barrel beat the longer ones with 3F - GOEX.  It wasn't a chronograph error as I double check with 2 of them, giving no more than 4fps difference, shot to shot, ones screens placed in front of the other.

Ball fit as well as lube and barrel interior condition probably makes a difference as well. These three things could easily  make shorter barrels faster than much longer ones.

Daryl, Why does Hanshi's long barrel shoot faster than the 20" with the same load?

[Daryl]

That is how it should be - given similar fit. The expanding powder gasses, having a longer tube to expand in, increases the speed of the projectile.