Velocity vs. barrel length with BP loads?

[Oregon Bill]

I'm about to order an 1873 carbine in .38-40, and plan to shoot mostly BP loads in it. I am thinking with Swiss or Old Enysford in that relatively small case, I won't lose all that much velocity in the 19-inch barrel vs. a 24 or 26. Am I on the right path here?

[w44wcf]

Bill,
Don't have a 38-40 but there was about a 40 fps difference between a 20" & 24" 44-40 with a full charge of 40 grs of Swiss 2f or only 10 fps loss per inch.

w44wcf

[Fox Creek Kid]

In an Uberti 19" carbine I got 1,050 fps using 28 gr. BP and a 200 gr. bullet. SD was single digits!! I believe it was FFFg.

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[Oregon Bill]

Kid, my carbine should be in my hands Monday or Tuesday, and I have brass, dies and a new 190-grain mold from Tom at Accurate Molds. I'll load up some rounds with drop-tubed Swiss FFFg and chrono as soon as I possibly can. Unfortunately, we are due for up to 10 inches of rain this week.

 

[w44wcf]

Bill,
A drop tubed charge of Swiss 3F  will likely produce about 100 f.p.s. more than Swiss FFG so I would think that velocity will be at least 1,300 f.p.s. and maybe a bit more (assuming the actual charge weight is 35 grs or so).

Have fun!

w44wcf 

[medic15al]

w44wcf,
   How long a drop tube you using?

[w44wcf]

medic15al,
Actually, I don't use a drop tube, I was repeating what Bill had said.  I have found by dumping the powder slowly into the case holding the powder pan 4-5" above the funnel settles the powder as much as it does in the 44-40 from a drop tube.

If I am loading a block of 50, I will place all the charges from a powder measure, then place a loading block on top, place a little downward pressure with my left hand then lightly tap the bottom block with a hammer 15 times or so. That will also settle the powder.

w44wcf

[King Medallion]

I tap the edge of the cartridge rim a few times on the table, settles the powder, I think, more than a drop tube.

[Fox Creek Kid]

medic15al,
Actually, I don't use a drop tube, I was repeating what Bill had said.  I have found by dumping the powder slowly into the case holding the powder pan 4-5" above the funnel settles the powder as much as it does in the 44-40 from a drop tube.

If I am loading a block of 50, I will place all the charges from a powder measure, then place a loading block on top, place a little downward pressure with my left hand then lightly tap the bottom block with a hammer 15 times or so. That will also settle the powder.

w44wcf

Our of curiosity, when you used a drop tube was it as least 18" high and did you pour the BP very slowly?

[medic15al]

Thanks w44wcf!   I use Lee equipment and the funnel in in the powder thru expanding die and gives me about 4 in drop. I do tap out the scoop slowly. I can get a full 2.5cc scoop ( 40 grns) of FFFG powder in it and seat the 250 gn bullet. ( .45 Colt)

Was just curious if a longer drop tube would be better.

[Fox Creek Kid]

Years ago an objective test was done in the Black Powder Cartridge News journal on drop tubing BP in full sized rifle cases. They found that 18" is optimal and that you must pour slowly & consistently to get the best results. However, you can get the same results by using something vibratory, e.g., setting a pan of loaded cases on a running tumbler for several minutes.

I have drop tubed 40 gr. of BP into a 44-40 case slowly at 18" and it does allow you a little more breathing room, but you still get grain crushing when seating the bullet. That said, I couldn't tell a nickel's worth of difference between those loaded with 40 & those with 36 - 37 gr. Just my 2 cents.

[Cliff Fendley]

I don't use a drop tube on the pistol caliber rounds. I've been using the tap the block method w44wcf described. It's amazing how much several light taps will settle the powder.

[Coffinmaker]

HEY !!!!  OREGON BILL !!!!

Knock Knock!!  Where is the "report back" you promised??  Hmmmm   You know the one .... your Brandy Knew 38-40 Carbine??

WELL ?

Coffinmaker

[Fox Creek Kid]

I don't use a drop tube on the pistol caliber rounds. I've been using the tap the block method w44wcf described. It's amazing how much several light taps will settle the powder.

CF, I actually spin the case loaded with powder like a top between my thumb & index finger on the benchtop a few times to settle the BP with pistol cases.