4 replies to this topic

[Dirtnap]

Good day, all!
I was looking into the Mk.22 3"/50calibers anti-aircraft gun and found that they had two distinct duel-gun mountings. The Mk.27 and the Mk.33.
The issue Is that, beyond a statement that the Mk.33 had "an improved slide" I can't seem to find the specific changes, nor if there were any other distinctions between the two mounts.

I was directed to ask here by a friend.

[Dave Franklin]

Sorry Dirtnap, all I found with a little "Google fu" was the statement on Navweaps "Mark 27 was the original twin mount, Mark 33 was an improved twin mount with a different slide and Mark 34 was the single mount version."  The data in the Gun Characteristics table lists Rate Of Fire at 45 - 50 rounds per minute.  Absent any other info, I might guess the Mark 27 was on the low end, and the Mark 33 and 34 were on the high end?

 

Dave

[Jim O'Neil]

I went through my library and found little more other than the Mk 33 was made in far larger numbers.  The gun itself was the standard 3" seen in pedestal mounts everywhere. he Navy just designed an automatic loading  system adapted to that gun. My guess is that the slide system for the Mk 27 was not up to the doubling of the rate of fire and was upgraded; the single manual mounts could achieve 25 rounds a minute or better, if the ammo supply could keep up. The twin automatic guns doubled that to around 50 rounds per minute. It would seem that these automatic 3"/50s  did not see use in WW2 and were applied in 1948, although that doesn't fit with my understanding. Naval Ordnance and Gunnery had little of use, and Campbell''s Naval Weapons of WW2 provides little information on them, as does Friedman's NAVAL WEAPONS.

[Dirtnap]

The Mk.34 mount I know to have been the Single gun mount, but I can't find anything specific on anything else effectively.
Thanks anyway.

[Jim O'Neil]

The single manual gun is better covered in all the book I mentioned above. It was widely used on many different sorts of ships and seems to have been readily available.