Salute to the big guns.

[lysanderxiii]

Also... 30mm is small arms? Naw. Once you get to to say 14.5mm (there are opinions where the cutoff is) it's a "cannon." Somewhere around 50-70 mm it becomes artillery, or a gun.

There is a lot of overlap. Stuff larger than .60 caliber (15mm) is generally called an automatic cannon, rather than a machine gun, but small arms ammunition includes ammunition up to and including 30mm.

 

[theotherwaldo]

Some folks say that if a person can hold a loaded round in one hand then that weapon is a small arm.

 

[CapnMac]

The line get blurry quickly once the bore gets to 1" or larger. Even the line between fixed, semi-fixed, and bagged ammo is blurry. USN fielded semi-fixed ammo for the Mk 16 8"/55 on the Des Moines class cruisers and had rates of fire high enough to be designated "dual purpose"--as in suitable for anti-aircraft fire as well as anti-surface fires.
The notion would be brought back, in my time, as the Mk 71 Major Caliber Lightweight Gun project.

One aspect of long-barreled naval rifles is that they are much like any other long-barreled rifle. putting the muzzle "out there" moves the effects "out there" too. Getting the barrel length out beyond 50 calibers or so tends to tame the muzzle blast. At least in naval rifles. And, luckily, the BOSS muzzle break would not be invented until well after heavy naval rifles fell out of fashion. []

Often people assume naval rifles have stupendous acceleration, too, and are surprised to find out the rounds are somewhat sedate at 2400 to 2600 fps at the muzzle.

Those Armstrong 100 ton guns are also unique in that they are rifled, too. The loading facilities at Gibraltar and Malta were set up to accommodate getting the driving bands to engage the rifling on loading. The Italian battleships wit h80 ton guns (that prompted the need for 100 ton guns) very very much limited in needing similar loading arrangements, where the muzzle had to be spun to the loading area between shots.

 

[jmr40]

Do punt guns count.



For those not familiar market hunting for ducks used to be legal. Such shotguns were mounted on small boats which were quietly paddled close to ducks sitting on water. One shot could kill dozens which were scooped up and sold at markets.

 

[CapnMac]

Back on the A-10--here's a long-ish video on loading one up

 

[shoobe01]

The line get blurry quickly once the bore gets to 1" or larger...

That.

Also lots of different terms. "Small caliber" is not directly related to "small arms." And even if you account for national preferences (we think over .50 is big, if you issue 14.5mm then that is often the cutoff...) then there's also context. If you are on a ship with any turreted gun, even as small as 70 mm, then all other guns are "the small caliber guns," and the same occurs when the organization defining stuff goes all the way up through acquiring artillery

I for one am very comfortable saying that it's only a "small arm" if it can be carried and fired by one man — it's not me, others use that sort of general definition. That DOES include some pretty big guns, but the usual cutoff is around M2HB, which people will occasionally load up and ruck as a whole kit on one guys back to prove to everyone it's a small arm vs whatever else ("crew served" is only sorta a useful term here) but really, precision rifles and AMRs aside, much over 7.62 is simply not a small arm to me.

 

[Pure2nd]

Is there a common reference for an explosive based projectile weapon?

 

[GJeffB]

Jayzus! And I thought my .45/70 was the nuts
Thanks for the great education, folks

-jb, and even more thanks to those who served

 

[jmr40]

Jayzus! And I thought my .45/70 was the nuts

Everything is relative. 45-70 was the original poodle shooter. The military went from 58 caliber down to 45. That was a bigger reduction in bore diameter than when they went from 45 to 30, and then from 30 to 22.

 

[Mauser lover]

Do punt guns count.

View attachment 1070132

For those not familiar market hunting for ducks used to be legal. Such shotguns were mounted on small boats which were quietly paddled close to ducks sitting on water. One shot could kill dozens which were scooped up and sold at markets.

View attachment 1070133

Does that thing use normal sized percussion caps, or was there a specialty size for them?

 

[jmr40]

Does that thing use normal sized percussion caps, or was there a specialty size for them?

I have no idea.

 

[I6turbo]

The A-10 gun.



The round.

 

[bangswitch]

16", 2700 pound projectile. The Mark 7 50 caliber naval gun could fire these at 2700 feet per second, about the same speed as a .308 rifle cartridge. Quite a kick, huh?

I get to Wilmington NC occasionally and the USS North Carolina batttleship is docked there and has been turned into a museum. I've been a couple of times. As battleships go it is smaller than some. It was designed right after WW-1, and served during WW-2. But those are still some big guns.

Prior to WW2, the South Dakota class of battleship were the largest US battleships to date

Yes and no. The North Carolina class ships (USS North Carolina and USS Washington) are longer than the South Dakota class, but the South Dakota class ships are heavier by 3000 tons. The extra weight is due to thicker belt and deck armor. The shorter length was to compensate for the heavier weight to maintain the same speed capability, as both classes use the same propulsion systems. They also carry the same armaments. The North Carolina class is only 1/2 knot faster. The North Carolina class ships were commissioned in April and May of 1941, the first of the South Dakota class was commissioned in March of 1942.

The recoil from 9 16”/50 cal guns is enormous, but an Iowa class BB is enormouser.

The 16" guns on the Iowa class are 50 caliber, so a broadside from any of them would be similar. The North Carolina and South Dakota class had 45 caliber 16" guns, the barrels were seven feet shorter than the 50 caliber guns. The 50 cal. had an effective range of 45,100 yards, the 45 caliber was good for 35,000 yards.

I had heard that 16" gun accuracy was mediocre. There were efforts during Desert Storm to improve the accuracy of the Missouri and Wisconsin 16" guns. In testing, they found the aggregate accuracy was within about 220 yards from aim point at 19 miles (33,500 yards). When you do the math, that's better than 1 MOA !

Some pics of the "Showboat", the nickname for the USS North Carolina:

 

[CapnMac]

I had heard that 16" gun accuracy was mediocre. There were efforts during Desert Storm to improve the accuracy of the Missouri and Wisconsin 16" guns. In testing, they found the aggregate accuracy was within about 220 yards from aim point at 19 miles (33,500 yards). When you do the math, that's better than 1 MOA !

Naval rifle accuracy is a complex topic.

Normally CEP is used to express the accuracy as being more apt in implementation.

The concept is that you want to hit an ellipse of about 600' wide by 200' deep, at a range of 15 to 20 miles.

The flight time at 15 miles is a bit over 30 seconds. And, as designed, you were shooting at targets that were moving.
So, 15kts is about 25 feet per second. In 30 seconds, that's 750 feet of movement. And, that's discounting your own movement, too. Which is why the Ford Instrument Company (not related to Ford Motor Company) built elaborate computing machines that not only solved for various Pythagorean and trigonometric problems, but also dealt with the curvature of the Earth, Coriolis effects, and every other measurable variable.

Now, what will make a long-range hit on a moving ships is not as ideal as a nice, fixed shore target. During Korea, Missouri was tasked to close a railway tunnel via offshore gunnery. The expended about 100 rounds to hit that 30 yard target at 12 miles' range.

 

[tactikel]

You must be referring to the Goldwater Air Force gunnery range in Arizona. Many times driving from Phoenix to Rocky Point Mexico I watches the A-10s come in low and “brrrrt” at the target tank hulks in the valley. Very cool.

My Dad served on the light cruiser Wilkes Barre in WW II she only had 5 and 6” guns but he said that when they lit off a broadside the entire ship jerked a couple of inches.

 

[herrwalther]

One of the many ranges I trained at in the military shared land with a General Electric R&D office. That would frequently do test fires of the Gau-8 Avenger 30mm, outside of an A-10. The training range is thousands of acres and the Gau-8 can be heard for miles. One time we wandered over there to watch it being fired and some of us got to "pull the trigger" on it, blowing up a tank carcass down range.

 

[Ignition Override]

The same basic engines used on the A-10 power the Canadair CRJ "Regional Jet".

 

[kwguy]

Even though a niche may be specialized, hopefully aircraft like the A10 will stick around. Politics and congress can have a way of getting rid of good pieces of equipment and capability for no good reason.



.50 cal HE rounds are nice too!