How accurate is your rifle at 34,000 yards?

[Jenrick]

Found an interesting article on naval guns. This is in reference to the 16"/50 Mark 7 guns on the Iowa class BB.

http://www.navweaps.com/Weapons/WNUS_16-50_mk7.htm

So if my math is right, this works out to .222 MOA?

As modernized in the 1980s, each turret carried a DR-810 radar that measured the muzzle velocity of each gun, which made it easier to predict the velocity of succeeding shots. Together with the Mark 160 FCS and better propellant consistency, these improvements made these weapons into the most accurate battleship-caliber guns ever made. For example, during test shoots off Crete in 1987, fifteen shells were fired from 34,000 yards (31,900 m), five from the right gun of each turret. The pattern size was 220 yards (200 m), 0.64% of the total range. 14 out of the 15 landed within 250 yards (230 m) of the center of the pattern and 8 were within 150 yards (140 m). Shell-to-shell dispersion was 123 yards (112 m), 0.36% of total range.

34,000 yards, means 1 MOA is 35604.7167406844 inches or 989.0199094635 yards, we'll round that to 990 yards. So a pattern of 220 yards is .222 MOA, not bad for a 15 rounds group. Smallest 8 group of 8 is .15 MOA, and the dispersion is .124 MOA.

So the next time someone is saying that they can shoot a .25 MOA or smaller group at 1K+ yards, before you say it's BS, you might ask if he's using a battle ship

Far as loadings go, how about a 13,300,000 gr (1,900 lbs) bullet if you like light and fast up to a 18,900,000 gr (2,700 lbs) if you believe in heavy and slower. Charges range from about 2,275,000 gr (325 lbs) for light practice loads, to 4,585,000 (655 lbs) for full power HD and hunting loads.

The D839 propellant grain used for full charges issued for this gun was 2 inches long (5.08 cm), 1 inch in diameter (2.54 cm) and had seven perforations, each 0.060 inches in diameter (0.152 cm) with a web thickness range of 0.193 to 0.197 inches (0.490 to 0.500 cm) between the perforations and the grain diameter.

Now time to find a bigger powder measure, as the Lee one I've got isn't going to meter those 2" long grains real well.

Just found this interesting, especially the relative accuracy of the weapon over the range.

-Jenrick

 

[jackdanson]

You really probably need one of these if you are hunting anywhere north of Iowa.

 

[General Geoff]

Big artillery guns will always be inherently more accurate in this sense, because gravity is more consistent than wind, which affects small arms projectiles far more profoundly than thousand plus pound projectiles.

 

[f4t9r]

How accurate is your rifle at 34,000 yards?

not very accurate at that distance. I did however make a good shot at 34 yards.

 

[hankdatank1362]

So, I found the OAL of the rounds... I guess the 16" refers to the diameter of the rounds?

And, holy moly, 280-350 rounds barrel life? That sucks!

 

[Almond27]

eh, I hit can hit a deer halfway behind a tree at 35,000 yards with my .300 winchester magnum, with the wind blowing at 24mph east. Its true I have done it before.

 

[Jeff F]

A whole new meaning to the term 'long range snipping'.

 

[oneshooter]

At Iwo Jima the Marines would locate a cave and mark it with smoke. One of the BB's offshore would fire a single 14" 1200lb HE round at the cave. The Marines would call in corrections as needed. The BB's were only 10,000 yard offshore so the HE rounds would strike at about 2000fps! A 14" 1500lb round could penetrate 8ft or more of reienforced concrete!!

The 250-350 round barrel life is using AP with full pressure charges.

Oneshooter
Livin in Texas

 

[gvnwst]

where can i get one? do i have to regester it as a DD?

 

[jerkface11]

If you were using the Iowa class against modern warships you wouldn't need the AP rounds none of them would be able to take a single hit from an HE and survive. Plus the Battleships would be totally immune to anti shipping missiles.

 

[General Geoff]

I've always wondered about that, how effective any modern anti-ship weaponry would be against an Iowa.

 

[Disgruntled]

"Big artillery guns will always be inherently more accurate in this sense, because gravity is more consistent than wind"

eh, not to pick a nit, but you might be thinking of inertia, not gravity.
Gravity is constant.

 

[W.E.G.]

You think that's a trick.

Don't forget about the trick of getting the outboard guns to fire simultaneously so they are not only accurate, but also so they don't rip the turret right off if fired out of sync.

 

[General Geoff]

eh, not to pick a nit, but you might be thinking of inertia, not gravity.
Gravity is constant.

Inertia is a constant as well. I'd say a perfectly constant law of physics is pretty consistent, don't you think?

 

[sarduy]

good to go varmint hunting

 

[Jorg Nysgerrig]

I've always wondered about that, how effective any modern anti-ship weaponry would be against an Iowa.

The original version? Very. The refitted version? Not quite as much. You have to keep in mind that they reactivated the Iowa class ships in the 80s and modernized them.

 

[C-grunt]

I've always wondered about that, how effective any modern anti-ship weaponry would be against an Iowa

I would think that a Tomahawk or similar type missile would do some serious damage to any ship. I would think that an anti-ship missile would have a warhead designed specifically for sinking boats.

Didnt the British lose a ship in the Falkins (spelling) to a missile?

 

[Powderman]

If you're curious about ASM and their relative effectiveness, look up some specs on the Silkworm, and most notably, the "Moskit" or "Sunburn" missiles.

Remember, you don't have to SINK a ship to render it combat ineffective.

 

[aspade]

Plus the Battleships would be totally immune to anti shipping missiles.

Yes and no. The protected parts of the ship - the main artillery, the magazines, the engineering spaces - would obviously be largely invulnerable to ASM warheads designed to destroy unarmored structure.

But the eyes and ears of the ship above decks - all the more so the electronics refitted later - are as vulnerable as those on any other ship.

USS South Dakota was soft killed at Guadalcanal by Jap 6 and 8" shells which are a lot less destructive than 700 lb Sunburn warhead.

 

[RecoilRob]

Double check the math....

Circumference of the circle @ 34,000yds = 3.1416x34000= 106814.4yds/360=296.707per degree 296.707yds/60=4.945 yds per minute

Edit: Just tried my math on 100yds and something is wrong....so the above isn't correct. Man, it is late! For some reason, the above method seems to be half of what is should be...but I am unable to see why right now. Perhaps it can jog the correct answer from someone.

Correct # is close to 29.75 feet. Math is funny sometimes when you cannot figure it out....

 

[Swampy]

RecoilRob is correct.....

1 MOA at 34k yards is somewhat on the order of 29-30 feet.... not 990 yards.

Best to all,
Swampy

Garands forever

 

[Walkalong]

Mine won't reach that far.

 

[Dr. Tad Hussein Winslow]

13 million grains for the light n fast crowd - tee hee.

 

[DPStx]

Math Problems.....

Gotta love math, my calculations are thus.....

Formula for circumference of a circle is C = 2piR or piD where R=radius, D=diameter.

c= 2 x 34000 x pi = 68000 x3.14.... which = 213628yds circumference.

divide this by 360 degrees and you get 593.4 yds per degree,
divide this by 60 minutes per degree and you get 9.89 yds per minute of angle

I believe this is one MOA at 34000 yds

 

[Coronach]

As aspade pointed out, there is a differnce between a hard kill and a soft (or mission) kill. A hard kill is a sunken (or badly crippled) ship. A mission kill is a ship that is damaged enough that it cannot complete its mission. Hard killing a modernized Iowa with missiles would be a difficult task. Soft-killing her would be easier.

The real danger to the old battlewagons would be torpedoes and mines. Modern torpedoes don't run into the sides of ships like they did in WWII. They run under them and detonate beneath the keel. The Iowa class BBs are no better protected against this than any other ship.

Mike