4 replies to this topic

[Jim O'Neil]

I was skimming through Koop & Schmolke's GERMAN LIGHT CRUISERS of WW 2 and became curious about

the claim that the the 149 mm/L60 gun of the German Light cruisers was an unusually powerful weapon for the time.

 

Some checking makes me feel that the gun was a mediocre performer although fairly heavy for its caliber.  The Germans

themselves eschewed it for any further use too. I made a rough comparison, using NavWeaps and such sources as I have

available and have found this much so far.  I have some requests out for more data, specifically on the Italian guns.*

 

​* And the response was amazingly quick!  My Italian Contact obviously is well thought of and has good connections!!

 

European 6” guns firing AP.

 

Muzzle velocity_________ ~10,000 Yards__________ ~16,000 yards

 

Germany

APC L3.7  100.3 lbs

15cm/60 SK C/25 ______10000 m/ 10940yds______ 15,000 m/16400 Yds

3150 FPS [960 mps] _____1460 fps [445 mps] ______1,043 fps/318 mps]

 

Britain

CPBC 112 lbs

6”/50 BL Mk XXIII ________10,000 yds_______________ 15,000 yds

2758 fps [841 mps] _______1371 fps [418 mps] _______1,098 fps [335 mps]

 

Italy

152 mm/53 Mods 26 & 29  APC is 109.3 Lbs. for both guns (per the Italian Navy in response to my request the shell

weighs 50 kg [110.23 lbs]

3281 fps [1000 mps]_______517 m/s (1.696,19 ft/s)______ 378 m/s (1.240,16 ft/s)

2789 fps [850 mps] derated

 

152/55 Mdl 1934 & 1936

2986 fps [910 mps]

900 m/s (2952,76 ft/s) _____ 435 m/s (1.427,72 ft/s)_______ 324 m/s (1.062,99 ft/s)

 

 

NOTE- Comparing vertical penetration numbers with the US 6”/53, the Italian gun penetrates 86 mm at 90º at 14,000 meters (vs homogeneous armor) and the US gun penetrates 2” at 13,800 yards  [12,620 meters]. The British 6”/50 Mk XXIII penetrates 3” at 12,500 yards [11,430 meters] vs NC armor. The document I have does not state muzzle velocity, butI have to assume it is the original higher number.

 

France

152/55mdl 1930

2,854 fps [870 mps]

 

USA

6”/53  105 lb common ________10,000 yards_______________ 16,000 yards

3,000 fps [914 mps] __________1580 fps [482 mps] __________1147 fps [350mps]

 

6”/47

105 lb common

2800 fps [853 mps] ___________1447 fps [441 mps] __________1106 fps [337 mps]

 

130lb APC

2,500 fps [762 mps] ___________1428 fps [435 mps] __________1129 fps [344 mps]

[jwsleser]

Just looking at the muzzle velocities at range, the Italy guns appear to hold a higher velocity than everyone else. The velocity of the German gun drops at longer ranges and is in the bottom of overall performance. Of course, there are other factors that affect the performance of guns besides velocity, but I am not reading anything special in this data set. 

 

v/r  Jeff

[Jim O'Neil]

Well the "Very Powerful" German gun isn't; it's a lighter projectile that  loses velocity more quickly than most of the others.

That said, I now can't find the place where I could swear I read about how heavy and powerful the 149/60 gun was.  

That's more irritating and what I get for not making note of it.  I would hate to have misspoken.

 

Ah Ha !!  I did misspeak, it wasn't Koop & Schmolke  at all, it was the intro for the gun in NavWeaps: 

"This weapon was used on light cruisers built in the 1920s and 1930s and was slightly more powerful than the 15 cm guns used on

battleships and destroyers. The Germans considered this weapon to be too heavy and powerful for any other 15 cm (5.9") application."

 

The Italian gun is  impressive in these numbers but had a very large longitudinal spread in its salvos. That is why there was a derated version made

to get the spread size down. A hit could be potent, but they were harder to get, and only hits count in the end.

 

The US 6"/53 performs a bit better than the German gun, but wasn't a very impressive performer in reality either.

 

Both the US 6"/47 and the Italian 152/55 are given high marks in overall performance at the end of the war, as is the British 6"/50 Mk XXIII, a slightly less powerful performer but still a great weapon that did yeoman service during the war.

[Jim O'Neil]

In searching the Internet I stumbled across this site:  https://www.navygene...iser-main-guns/

 

It is only interested in the gun performance itself and ignores fire control and other outside issues. So not the most effective guns, just the best for range, payload and velocity i assume.  That said, it is interesting to see which guns it rates best. In actual combat, I'd still take a BROOKLYN or CLEVELAND, but other guns were a bit better.

[jwsleser]

Interesting comparison. As the author states this isn't absolute in terms of overall effectiveness.