75mm Recoilless Rifle - M-309 (A1) projectile


#1

Some may remember my thread on the 120mm cartridge - viewtopic.php?t=8352

Well, I have another itch that needs scratched.

I have a 75mm case (or two) and think I need an M-309 projectile. Since I can’t seem to find one, I suppose I will build one.

This project will be on my metal lathe. I need to practice my skills - or perhaps develop my skills? - on the metal lathe. I like to turn aluminum because it is easy, so this project will be aluminum unless I can stumble upon an appropriate sized chunk of steel. So far I have produced a couple of projectile “fuzes” from aluminum.

Anyway, does anyone have the measurements for the M-309 projectile for the 75mm Recoilless Rifle? I have a M-557 PD fuze I will be using.

I have some photos of the projectiles and TM 43-0001-28. If I have to, I will draw it out in my CAD program. Close enough will be close enough, since I am not trying to fool anyone (aluminum, remember?).

Thanks in advance.


#2

Might it be easier to just take a regular 75mm and alter it?


#3

Maybe and willing to consider all options.

Got any “regular 75mm” projos - or know where I can get one?


#4

Turning the projectile will be easy. But, the recoilless rifles use “pre-engraved” rotating bands with about 30 rifling grooves about 3/16" wide cut across them at a slight angle. That will be a bit harder to do.

57mm Recoilless projectiles are not that scarce, but the fuzes seem to be hard to find. I think Indiana Surplus had some recently, and that would be much more authentic, and a lot less work than making your own.


#5

[quote=“JohnS”]Turning the projectile will be easy. But, the recoilless rifles use “pre-engraved” rotating bands with about 30 rifling grooves about 3/16" wide cut across them at a slight angle. That will be a bit harder to do.

57mm Recoilless projectiles are not that scarce, but the fuzes seem to be hard to find. I think Indiana Surplus had some recently, and that would be much more authentic, and a lot less work than making your own.[/quote]

Yes, I agree with the “pre-engraved” rotating band part. It might be difficult, but I bet I can do it - somehow.

I do have a 57mm projectile is my collection (also without a fuze). I believe you are correct about the availability of the 57mm fuzes. I am still looking for one.

Perhaps a fuze for the 57mm will be a project before this 75mm projectile project.

It is kind of ironic. I have a fuze for the 75mm, but no projectile - and - I have a projectile for the 57mm, but no fuze.

I checked with Indiana Army Surplus. They had a variety of 57mm, but no 75mm projectiles - and no fuzes listed for the 57mm either.


#6

Someone was making resin copies of the 57mm recoilless fuzes- fantastic quality, including marking details. I do not remember who, though.


#7

That 120mm TPCSDS-T you made was a work of art and extreme craftsmanship! I am really looking forward to seeing your next creation :-)

Jason


#8

Priced some 3" x 12" aluminum today = $38

1018 Cold rolled steel at the same size = $42

That surprised me. I thought steel would be less expensive than aluminum. Not a problem, since aluminum is easier to turn.

I think I will spend some time tomorrow and try to find some more aluminum. The piece I priced was in Omaha, NE (about one hour West of home) and I could not get it today, (when I was over there this afternoon) due to their schedule.

Options? Find one closer to home - or make another trip to Omaha.

Nothing is easy, when you do things the hard way. :>)


#9

I found a fairly good photo of an M48 projectile that seemed to import well into my CAD program, so at least I have somewhere to start.

I will try and post photos, as the project comes along. No promises of a timeline. I am a fairly busy guy for a retired guy.


#10

Over all length is all I can find at the moment, TM 9-1300-203; 1967:

Brian

P.S.- Diagram:


#11

Gunnut

You don’t need a solid round of steel to make a projectile. Get a piece of tubing with the correct outside diameter and a hole the same size as the fuze thread. It will be a lot cheaper and easier to work with. I use On-Line Metals for all of my stock. You can also get a short piece of copper round to make a rotating band.

Here are three VT fuzes that I made. The ogives are cast fiberglass. MT fuzes can be made the same way except you can’t use fiberglass for the ogive.

And, a 3" projectile I made. The fuse is an original.

Ray