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UNUSUAL 25MM APFSDS-T Round - UNDERWATER CAVEATING?

apfsds

Well-Known Member
Premium Member
Been busy unpacking my collection after the construction of my new house and came across this unusual 25mm APFSDS-T round. To be honest, I don't even remember buying it LOL. In any case, the tip design of the of sub projectile dart is unusual. Instead of tapering to a sharp point or having a separate windscreen incorporated to reduce aerodynamic heating like most APFSDS rounds, this one tappers then straightens out on the last mm with a blunt tip. Tool marks indicate that it was not simply cut blunt, but rather fabricated this way with a lath type tool. I have read about some 25MM or 30MM APFSDS rounds designed with blunt tips so that they caveate when fired at underwater sea mines. Could this be one? Weird either way.

Jason
PS: One photo is of a drawing I did to try and detail the unusual tip tapper. Very hard to see in photos of the actual projectile as it is subtle.
 

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I have not heard of any of the super-cavitating APFSDS projectiles being made in 25 mm calibre: for the RAMICS anti-mine programme they were developed in 30 x 173, and are still made in that size (Mk 258 Mod 1) although now for shooting through waves, so they can hit small boats. However, it is possible that these rounds (also known as hydroballistic or "Swimmer") were made experimentally in 25 mm - the nose tip on your projectile looks to have the right shape.
 
Hi Jason,

I have only seen this type of supercavitating round referenced in 30x173. Nammo is making a APFSDS-T Swimmer round, the Mk258 Mod1. This is intended for anti mine and anti small vessel warfare. (I see Tony just beat me to it)
Mod 0 and Mod 1.JPGNammo-swimmer.JPG
 
Thank You Both SOOOOO MUCH!

The tip looks exactly like the MOD 1 30mm Swimmer you guys are talking about. I was thinking that my 25 could be an experimental because each sabot petal is hand engraved with a #1, #2 and #3 which I assume is for recovery and study? Thank you, Both!

Jason
 
PS: I also have an Israeli 40MM APFSDS-T round with this same tip design feature.

Jason
 
I used to work on the 25mm chain gun that was used on LAV's and am not familiar with this projectile. The first cut away picture definitely looks like a 25mm shell casing.
 
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