40MM and 37MM questions


#1

Thanks to a comment in a post from Tony Williams, I took a relook at my 40MM collection and noticed a difference in the cases of the 40 X 364 and 311R. Considering the lack of a base groove on the 364, I assume these were not considered for loading in clips, to be loaded individually. If anybody has a fuse cap for the 364, please PM or email me. Inert Filled projectile has an ID of 28.73MM/1.1" , TPI 24. Is there a different option for projectiles between the 311R and 364?

This is a spent 37MM projectile. Fuze appears to be a solid chunk of a not too hard metal. Appears aluminum in color, but a little tougher. Spent tracer crud is apparent in the base in a hole about 10mm in diameter. My guess is it’s a 37 X 223R loading. Anybody know?
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#2

Rick, the 40mm projectiles are all different and not interchangeable between both cases. The 365mm one with the HE shell requires a proximity fuze. This round was made for the Sgt York AA system (tracked vehicle).


#3

Rick,

Your fired 37mm projectile is the M55A1 TP-T, used in both the Mk.III Series and M17 Series cases during WWII.

Jim


#4

Thanks for the ID, guys.

Jim,
Are the MkIII and M17 series the guns or round designations? Found one pic of a 37MM with the loads. The HE round looks VERY similar to the TP round. Color is just about the only exterior difference. The fuze tip is a little different but appears to be of the same material. I’m playing like they’re HE. Did the HE have a tracer as well? I have 2 of them.


#5

[quote=“slick rick”]Thanks to a comment in a post from Tony Williams, I took a relook at my 40MM collection and noticed a difference in the cases of the 40 X 364 and 311R. Considering the lack of a base groove on the 364, I assume these were not considered for loading in clips, to be loaded individually. If anybody has a fuse cap for the 364, please PM or email me. Inert Filled projectile has an ID of 28.73MM/1.1" , TPI 24. Is there a different option for projectiles between the 311R and 364?

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Rick,

Both the 40/60 and 40mm L70 rounds used a four-round clip. The clips are, of course, different because of the lack of a groove above the rim on the L70 and its larger rim diameter. The UK 40mm L70 guns ran at 250 rounds per minute so a gunner would have to be fast on his feet if single-loading.

gravelbelly


#6

Thanks gravelbelly. Having read up on it a little more, I noted the rates of fire for the L70. That would be one busy fellow. Now all I have to do is acquire an L70 clip.


#7

Rick,

When I find where I have put mine I will post scans/photos of some of these clips.

gravelbelly


#8

Please advise if you have an extra L70 clip.


#9

Here are my “regular” 40MM clips(I think that’s a .30-06, I took these a while back):

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#10

Here are some pics of a 40/70 clip.

Cheers,
Andy




#11

Thanks Andy


#12

Rick,

The Mk.III and M17 designations are those of the cartridge cases, and will be found stamped on them.  The 37mm TP-T was the M55(or M55A1) and was fitted with the M50 Dummy Fuze.  The HE-T was the M54 (or M54A1), and was fitted with the M56 PD Fuze.  Other than stampings (on the rotating band and fuze), the M56 PD  has a large brass screw in the side, which the M50 Dummy Fuze lacks.  Note that inert loaded M54 HE-T projectiles fitted with inert M56 PD Fuzes are known.  These will be marked "INERT" or something meaning the same, but if fired, that may not be evident.  Normally, impact will severely damage the M56 PD Fuze, inert or not, as it is fairly thin-walled to contain the internal components.  The M50 Dummy Fuze is a solid piece of aluminum normally, although multi-piece ones are also known.

Jim


#13

Jim

Whew! These are definitely dummy projectiles. Thanks much for the details. One can never be too careful.