.50-70 '63 Sharps carbine

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SchuetzenDave
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Joined: Mon Jan 07, 2013 9:07 am
Location: St. Albert, Alberta

Re: .50-70 '63 Sharps carbine

Post by SchuetzenDave »

The early .50-70 rifles had a 48:1 twist barrel and were designed to shoot 330 grain bullets.
The later .50-70 rifles had the 36:1 twist barrel and were designed to shoot 450 grain bullets.
Have you checked the twist of your barrel to make sure you are firing a bullet of the correct length for your barrel?

63 grains of GOEX FFg will push the 450 grain bullet 1,195 fps so your 70 grain load and the more powerful Swiss should put you over 1,250 fps.
SchuetzenDave
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Joined: Mon Jan 07, 2013 9:07 am
Location: St. Albert, Alberta

Re: .50-70 '63 Sharps carbine

Post by SchuetzenDave »

For a 42:1 twist the gyroscopic stability factor (Sg) for your 450 grain bullet is:

Caliber 0.515 Inches
Bullet Weight 450 Grains
Bullet Length 0.972 Inches
Barrel Twist 42 Inches/turn
muzzle velocity 1200 fps
Temperature 50 degrees Fahrenheit (59 is standard)
Pressure 29.92 inches of mercury (29.92 is standard)

Sg = 1.28

Sg shouldn't be less than 1.4. It is not spinning fast enough and will tumble instead of flying straight.
It can also get worse under colder temperatures and higher atmospheric conditions.
Solution is to use a shorter bullet.
SchuetzenDave
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Joined: Mon Jan 07, 2013 9:07 am
Location: St. Albert, Alberta

Re: .50-70 '63 Sharps carbine

Post by SchuetzenDave »

If you only have a 42:1 twist you are best to use 400 to 425 grain bullets.

425 grain cast bullet 1,448 fps 1,979 ft. lb.

- since the 450 grain bullet was for use in the 36:1 twist barrels.
SchuetzenDave
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Joined: Mon Jan 07, 2013 9:07 am
Location: St. Albert, Alberta

Re: .50-70 '63 Sharps carbine

Post by SchuetzenDave »

If you have a 36:1 twist barrel the 450 grain bullet will have the correct gyroscopic stability.


Caliber 0.515 Inches
Bullet Weight 450 Grains
Bullet Length 0.972 Inches
Barrel Twist 36 Inches/turn
muzzle velocity 1200 fps
Temperature 50 degrees Fahrenheit (59 is standard)
Pressure 29.92 inches of mercury (29.92 is standard)

Sg = 1.74
bobw
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Re: .50-70 '63 Sharps carbine

Post by bobw »

It is distinctly possible that is a battlefield sight setting for 200 yards most trapdoors were set that way.
bobw
Don Kenna
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Location: Malta, Montana

Re: .50-70 '63 Sharps carbine

Post by Don Kenna »

Bear in mind that the .50/70 has a very arched trajectory, much more so than slightly later cartridges such as the .45/70. With a load very similar to yours, my .50/70 carbine shoots about as high as yours does at 50 yards. At 100 yards, it shoots even higher—roughly 15 to 16 inches high. That’s because the bullet is still climbing at that range. I found that the battle sight shot to point of aim at 175 yards. At 200 yards, I can either use the battle sight to aim slightly above the top of a 10-inch bull, or raise the leaf which, at its lowest setting, requires holding about 8 inches low.
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kenny s
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Location: Venice FL

Re: .50-70 '63 Sharps carbine

Post by kenny s »

I have an original 50 70 carbine too. lined barrel as most of them.
perfect bore, and I mean perfect. probably redone and not reissued.??

darn thing puts them all in 2 inches at 50 yards. same load you are using.
shells eject so hard I have to go looking for them.

This is the gun I would have carried 'back then' if I had a choice.

Nice piece of history....Ken
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