Info wanted 3.5 Inch Rocket fuze

[Madbomber31]

Hey guys i need some info on the 3.5 Inch rocket fuze.

The holes and form of the safety pins in the fuze whats the differds between the Prac and the HEAT.

Dutch, UK and US made versions.

Thanks for your help.

[Slick]

Madbomber

Here are some scans from TM 43-0001-30 that show the difference in the Practice, HE and Smoke(WP) fuzes. Along with external pics of some in stock examples.

[blu97]

For the Dutch the HEAT is square and the prac is round. I read somewhere that in the US the early ones was round , but these werent used in Holland.

[Madbomber31]

Hi guys,

Thanks for the replys.

Just one more

slick are thees in your own colection?
Can you make one more photo of the Live one when the safety pin is out from the hole and the complete rocket showing the hole in the fuze??

[Slick]

Yes. They are in my collection. The safety pin does not come out. At least not by twisting or pulling. The hole is round but the pin, as can be seen, has a square shank. Sadly, I don't have a safety pin for either of my practice rounds, so can't confirm the square vs round as noted by blu97.
And to clarify, none of these are "live". The M28 has been inerted and the M29s are spent.

[Madbomber31]

Hi Slick,

Thank you for your help so far.

[EODGUY]

I cannot find any reference to square or round safety pins in my manuals or drawings. Normally that level of detail is not placed in manuals so it would have been lucky to find it. I have attached a portion of the engineering drawing for the M404A2 fuze, but it does not address the pin shape. Neither does the drawing from TM 9-1950, Feb 1958 which I also attached. The M28 (T80E2) HEAT warhead used the M404 or M404A1 fuze. The M28A2 HEAT used either the M404A1 or the M404A2 fuze. The spike nosed version, the M35 (T205E1) used the M408 and the M35A1 HEAT used the M408E1 fuze. The M29A1 and M29A2 Practice rounds used the M405 fuze. The Practice M36 (T206E1) version of the M35 had no fuze. The T127E2 Smoke used the M404A1 and the T127E3 Smoke used either the M404A1 or the M404A2 fuze. The manual mentions nothing about the differences in any of the fuzes. The difference between the M404, the A1 and the A2 could be slight design changes (such as a square versus round pin), different materials used, etc. The drawing from the manual shows a round pin for what that is worth. The M405 is basically an inert body assembly of the M404 series fuze. The manual states that it is an inert fuze similar in appearance to the M404A2 to simulate handling and pin ejection. It does say that it uses a bore-riding, round ejection pin. Sorry but I can't pin it down. To the best of my recollection I do not recall seeing a square pin on a US round, but when I was dealing with them that was a level of detail that normally I didn't get into. The only example I have is an M-1 HEAT version made by CEV in Brazil. It is basically a copy of the US M28 and the pin is round.

[inertordnance]

My M404A1 BD Fuze Example Dated 9-1953, uses a square shaft safety pin in a square hole. The hole is also slightly counter-bored round on the surface of the fuze body for the safety pin spring. When the safety pin and spring are inserted in the fuze body, the hole appears to be round from the surface.

[Madbomber31]

Thank you EODGUY that is the drawing iam looking for, i didn't find it in my documents.
Thank you Inertord for this Photo.
Also thanks to the guys how PM me about it.

[Slick]

Just took a closer look after readinginertordnance's comment and seeing his pic. The safety pin hole in mine is akin to that pictured vs my previous description as being round.