Ok, next artillery Q

There is a slight difference between "calibre" (caliber, take your pick of spelling) which is the diameter of the bore, and the "calibre length" of the barrel. The latter refers to the length of the barrel measured in terms of the bore diameter.

The length of the barrel of your 155 mm (about 6 inches bore) 39 calibre barrel would be 39x155mm, or about 20 feet. The 155 mm 52 calibre barrel would be 52x155mm, or about 27 feet long.

Another example is the Navy's 3"/50. 3 inches bore, 150 inch barrel length.

The distinction could be important. For example, the Bofors 40mm/60 was quite a different gun from the 40mm/70.

Barrel length is an internal measurement and does not include things like muzzle brakes, breech mechanisms, etc. It's not usually a useful measurement for modelers.

Cheers,

Doc

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Doc Hopper
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I have a Hobbycraft AS-90 SPG which is going on the bench as soon as the Humvee is done (another Hobbycraft kit). In the destructions it shows a barrel add-in piece to change the 155mm gun from 39 caliber to 52 caliber. I remember Naval guns being referred to as 5 inch 38's, which meant 5 inch

38 caliber. Hmmm, ok, I guess. In small arms, caliber refers to bullet diameter (.50 cal is .500", .45 cal is .450", etc), but apparently not in the big stuff? I'm ex-Navy, but I was in the aviation end of things (F-14 squadrons), so all the heavy gunnery stuff was pretty much irrelevant.
Reply to
Disco58

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