daveg.inkc
Hunter
Then add in the year .30'06. Then the powder charge .45-70
Musings of a newbie
- Thread starter Durango Dave
- Start date
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OP wrote,
"Of course the barrel can't be exactly 9 mm or bullets simply wouldn't fit. Power may force the bullet out the barrel with a lot of wear"
Two issue to understand. Metal hardness and pressure.
Hardness
Bullets don't fit because they aren't suppose to. Soft bullet lead must get squeezed into the hard steel barrel grooves which changes whatever diameter they started as. If the squeezing doesn't happen, the hot gases escape past the base of the bullet and melt lead to the barrel (very bad). Accuracy is gone.
Barrel wear does not occur because the steel is much harder than the soft lead.
Pressure:
Friction is not bad. We need it for the cartridge and the gun.
Pressure starts to build in the case as soon as the primer starts to burn (not explode) the powder. Friction is required between the brass case and the bullet for the Pressure to build before the bullet exits the brass case.
Did this help at all in answering your questions?
Prescut
"Of course the barrel can't be exactly 9 mm or bullets simply wouldn't fit. Power may force the bullet out the barrel with a lot of wear"
Two issue to understand. Metal hardness and pressure.
Hardness
Bullets don't fit because they aren't suppose to. Soft bullet lead must get squeezed into the hard steel barrel grooves which changes whatever diameter they started as. If the squeezing doesn't happen, the hot gases escape past the base of the bullet and melt lead to the barrel (very bad). Accuracy is gone.
Barrel wear does not occur because the steel is much harder than the soft lead.
Pressure:
Friction is not bad. We need it for the cartridge and the gun.
Pressure starts to build in the case as soon as the primer starts to burn (not explode) the powder. Friction is required between the brass case and the bullet for the Pressure to build before the bullet exits the brass case.
Did this help at all in answering your questions?
Prescut
More detail on pressure:
Heavier bullets are harder to push and create more pressure than lighter bullets. More pressure gets more velocity.
More pressure is built as the bullet travels past the forcing cone and into the barrel grooves. Pressure continues to push the bullet while it travels down the barrel. Therefore, pressure/velocity increases with barrel length.
Pressure is the key to understanding ballistics. Pressure is how everyone measures what is going on. Understanding pressure is what keeps all of us from blowing up.
Prescut
Take notes, there will be a test !
Heavier bullets are harder to push and create more pressure than lighter bullets. More pressure gets more velocity.
More pressure is built as the bullet travels past the forcing cone and into the barrel grooves. Pressure continues to push the bullet while it travels down the barrel. Therefore, pressure/velocity increases with barrel length.
Pressure is the key to understanding ballistics. Pressure is how everyone measures what is going on. Understanding pressure is what keeps all of us from blowing up.
Prescut
Take notes, there will be a test !
coach
Hunter
Best comment yet.contender said:
I still learn things I never knew, forgot or learn about new developments in the topic after 30 years.Pal Val
Buckeye
Caliber is an instance of a word evolving through use. In the early days of cannons, the gunner had to make sure the ammunition, which often was a stone ball, would fit in the cannon bore. The bore inside diameter was known, and a small amount of extra space was added, called "windage", to prevent the gun from exploding from excess pressure caused by a stuck ball. The tool used to make these measurements was a caliper. The tool "caliper' got its name from the Latin word for steel, as calipers were often made of steel, due to the heavy use given to them. Somehow, the word evolved from "caliper' to "caliber", with the oldest references to the new word being in French texts.
There are stories of Spanish gunners of the Great Armada failing to "caliper" their ammunition before facing the English with the result of many gun failures, contributing to the defeat. They had to do this because they were firing guns made in Italy and ammunition made in Holland, with different measurement standards. English guns had been standardized previously, with guns classified as to the weight of iron balls they fired. This gave us the "six-pounder", the "eight-pounder", etc.
There are stories of Spanish gunners of the Great Armada failing to "caliper" their ammunition before facing the English with the result of many gun failures, contributing to the defeat. They had to do this because they were firing guns made in Italy and ammunition made in Holland, with different measurement standards. English guns had been standardized previously, with guns classified as to the weight of iron balls they fired. This gave us the "six-pounder", the "eight-pounder", etc.
22/45 Fan
Hunter
Every one of those cases you show use the same 9 mm (0.355") bullet and all are 9 mm cartridges. The cases vary in length, head size and other dimensions (and allowable pressure) but they are all true 9mm cartridges.Durango Dave said:While I used to think caliber always meant the diameter of the bullet. I now realize this term does not have a standardized meaning. Sometimes it's the diameter of the bullet, sometimes the casing, sometimes the barrel and sometimes the caliber does not correlate to any specific dimension. For example it seems that a 9mm bullet was originally 9mm in diameter. Then they made variations on this cartridge and nothing is 9mm any longer.
Cartridge nomenclature is obscure enough. Don't make it any more difficult than necessary.
Durango Dave
Single-Sixer
The diameter at the top is the bullet. Most 9 mm bullets are more than 9 mm. Here's a more complete list:
https://en.wikipedia.org/wiki/9_mm_caliber
https://en.wikipedia.org/wiki/9_mm_caliber
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