Sharps Infantry rifle Load chamber pressure?

[Smoothbore]

Anyone have any idea what chamber pressures are for a 59/63 Sharps infantry rifle with a 70 Grn service charge of powder?

Thanks, Dan

[Greg Ogdan, 11444]

Not enough to cause a safety problem, but plenty enough to cause premature pressure plate erosion. My suggestion would be for general shooting to limit the charge to around 50g of FFg. Using a heavier charge or using FFFg will just erode the face of the pressure plate faster.

[Don Dixon]

The more critical issue is accuracy.

In the Shiloh reproductions - that's what I have, so that's all that I can talk about - there is an accuracy sweet spot at about 850 to 900 feet per second of velocity. Why do I know? - I've chronographed a wide variety of loads. 45 to 50 grains of Swiss FFFg will produce that.

Larger volumes of powder might be useful at longer distances, but we are talking about N-SSA shooting here. Larger volumes of powder will, as observed above, also produce greater and faster erosion of the breech plate.

Regards,
Don Dixon
2881V