Black Powder and Rate of Fire

pushmar wrote:It's been said before about just changing up ammo for the M96's, from black power to smokeless.

Won't work out too well.

The rifling twist rate on black power is way too "slow" - around 48-54 turns per inch, whereas smokeless power requires a faster twist rate, say, 1o to 18 TPI, depending on diameter (caliber) and bullet weight.

Accuracy would be drastically poorer. Almost like a smooth-bore.

Not to mention - have you ever seen a black-powder weapon loaded with smokeless powder? You'd be lucky to keep your fingers or hand on after. The chamber pressures are much higher with smokeless.

Unless, or course, the M96's were designed to handle that higher chamber pressure.

My 2 cents.

Which is exactly what they said they were doing, and they did mention that the rifling was different on the M96 rifles than on the older ones.

fallsfromtrees wrote:

pushmar wrote:It's been said before about just changing up ammo for the M96's, from black power to smokeless.

Won't work out too well.

The rifling twist rate on black power is way too "slow" - around 48-54 turns per inch, whereas smokeless power requires a faster twist rate, say, 1o to 18 TPI, depending on diameter (caliber) and bullet weight.

Accuracy would be drastically poorer. Almost like a smooth-bore.

Not to mention - have you ever seen a black-powder weapon loaded with smokeless powder? You'd be lucky to keep your fingers or hand on after. The chamber pressures are much higher with smokeless.

Unless, or course, the M96's were designed to handle that higher chamber pressure.

My 2 cents.

Which is exactly what they said they were doing, and they did mention that the rifling was different on the M96 rifles than on the older ones.

Yeah. The M96 was designed for smokeless powder. They're only still using black powder because they don't have smokeless production up to where they like it yet.

pushmar wrote:
The rifling twist rate on black power is way too "slow" - around 48-54 turns per inch, whereas smokeless power requires a faster twist rate, say, 1o to 18 TPI, depending on diameter (caliber) and bullet weight.

The twist rate needed for a particular gun is based on how fast you need to spin the bullet in flight to stabilize it. The velocity of the round and the bullet weight (which decides the bullet length since diameter is dictated by the bore diameter) are the defining factors. Propellent isn't a factor.

Using smokeless just means you have a capability to increase the velocity of a BP designed round. It doesn't automatically mean that the velocity increase will happen. It is quite possible (and easy) to duplicate the external ballistics of a BP era round using smokeless powder. Ammunition manufacturers do it every time they load a 250gr .45Colt round to 850-900fps and, as a reloader, I've done it countless times over the last 20 years for everything from .45 Colt to .44 Bulldog.

pushmar wrote:
Not to mention - have you ever seen a black-powder weapon loaded with smokeless powder? You'd be lucky to keep your fingers or hand on after. The chamber pressures are much higher with smokeless.

Unless, or course, the M96's were designed to handle that higher chamber pressure.

My 2 cents.

I've seen it done a lot but I won't do it personally. There are a LOT of original BP era shotguns that have been shot using smokeless powder that haven't had a catastrophic failure- including Damascus barreled guns. I won't take that chance and advise others to avoid it as well.

Actually, all of John Moses Browning's designs made the transition from BP to smokeless without any redesign. It was necessary in a couple cases to change manufacturing techniques or materials (like the Model 1887 Winchester barrels were made by using a mandrel and welding instead of the fluid steel barrels used in the subsequent Model 1901) but the actual designs were strong enough to make the transition unchanged.

If the design is 'overbuilt' (as military guns tend to be) enough for BP cartridges and the metallurgy is good enough (and it should be- RFC has stated numerous times that Safehold's metal working capabilities are par with early 20th Century Earth), then there's no need to rebuild or redesign the gun to shoot smokeless. All you have to do is match the velocity of the BP round and use the same bullet.

I figure the gun was designed with the transition in mind- via Owl's computational abilities and Howsyn's steering and input, so I'm not overly concerned.

Here is an example of an "automatic" weapon at the end of the Black powder era, about 10 years before the introduction of Poudre B.

http://www.forgottenweapons.com/manual- ... ng-cannon/

Steve

pushmar wrote:It's been said before about just changing up ammo for the M96's, from black power to smokeless.

Won't work out too well.

The rifling twist rate on black power is way too "slow" - around 48-54 turns per inch, whereas smokeless power requires a faster twist rate, say, 1o to 18 TPI, depending on diameter (caliber) and bullet weight.

Accuracy would be drastically poorer. Almost like a smooth-bore.

Not to mention - have you ever seen a black-powder weapon loaded with smokeless powder? You'd be lucky to keep your fingers or hand on after. The chamber pressures are much higher with smokeless.

Unless, or course, the M96's were designed to handle that higher chamber pressure.

My 2 cents.

Just a not so irrelevant nit. That's inches per turn, not turns per inch. 48 turns per inch is fine on a small machine screw (standard for a number three,) but it would be a ridiculous spinner on a rifle bore.

ksandgren wrote:
Just a not so irrelevant nit. That's inches per turn, not turns per inch. 48 turns per inch is fine on a small machine screw (standard for a number three,) but it would be a ridiculous spinner on a rifle bore.

Talk about excessive barrel wear. Maybe they can leak that to the church as a way of hyper stabilizing the rounds for increased distance and accuracy.

fallsfromtrees wrote:

ksandgren wrote:
Just a not so irrelevant nit. That's inches per turn, not turns per inch. 48 turns per inch is fine on a small machine screw (standard for a number three,) but it would be a ridiculous spinner on a rifle bore.

Talk about excessive barrel wear. Maybe they can leak that to the church as a way of hyper stabilizing the rounds for increased distance and accuracy.

Thus is born project "The Marine Who Never Was".

fallsfromtrees wrote:

ksandgren wrote:
Just a not so irrelevant nit. That's inches per turn, not turns per inch. 48 turns per inch is fine on a small machine screw (standard for a number three,) but it would be a ridiculous spinner on a rifle bore.

Talk about excessive barrel wear. Maybe they can leak that to the church as a way of hyper stabilizing the rounds for increased distance and accuracy.

Having too fast a twist rate can literally spin a bullet apart in midair.

Saw it happen back in the early '90's with a guy shooting either a .22 Hornet or a .22-250 (it was almost 25 years ago, so the memory has gotten hazy) at the Ft Benning, GA Pistol and Rifle Club range. He'd changed bullets (and bullet weights)for his hand loads for the gun and was testing them. they grouped fine at 50 and 100 yards but he couldn't find paper at 200. He asked me to spot for him to see if I could see the dirt fly up where the bullet was hitting. I couldn't see where the bullets were impacting, but I did notice a little gray smudge in the air about 150-175 yards out every time he fired. Come to find out, it was the bullet falling apart in mid air.

The .22 centerfire rounds are really bad about it happening. You have to match bullet weight to twist rate on the gun you are shooting. If you go too light on the bullet, they tend to fall apart after a couple hundred yards. If you go too heavy, the bullet isn't stabilized well enough to shoot accurate, consistent groups.

ksandgren wrote:Just a not so irrelevant nit. That's inches per turn, not turns per inch. 48 turns per inch is fine on a small machine screw (standard for a number three,) but it would be a ridiculous spinner on a rifle bore.

I stand corrected. You're right. Thank you.

jtg452 wrote:...
Having too fast a twist rate can literally spin a bullet apart in midair.

Saw it happen back in the early '90's with a guy shooting either a .22 Hornet or a .22-250 (it was almost 25 years ago, so the memory has gotten hazy) at the Ft Benning, GA Pistol and Rifle Club range. He'd changed bullets (and bullet weights)for his hand loads for the gun and was testing them. they grouped fine at 50 and 100 yards but he couldn't find paper at 200. He asked me to spot for him to see if I could see the dirt fly up where the bullet was hitting. I couldn't see where the bullets were impacting, but I did notice a little gray smudge in the air about 150-175 yards out every time he fired. Come to find out, it was the bullet falling apart in mid air.

The .22 centerfire rounds are really bad about it happening. You have to match bullet weight to twist rate on the gun you are shooting. If you go too light on the bullet, they tend to fall apart after a couple hundred yards. If you go too heavy, the bullet isn't stabilized well enough to shoot accurate, consistent groups.

As for cartridge, what you may have seen was a .22 Hornet optimized projectile (see Sierra 40/45 gr) being fired from a .22-250.