How were APC windshields made?

[DEADLINE222]

After having much success machining several windshields for 37mm and one for a 75mm, I am experiencing great difficulty trying to make one for my 57mm M86.


I find that the area where the windshield should crimp onto the ballsitic cap leaves very little material on my windshield to work with, and almost negitive room for error.

I have considered turing material off of the 57mm's ballisitc cap, but I do not like to remove original material, and keep things as historically accurate as possible.

Is there and "easier" way?


And, how were these things origionally made? Were the machined, pressed or metal spun?

 

[DEADLINE222]

Ah, a very enlightening conversation we are having here.

A new day yeilds my typical progress.

This projectile will be set up as OD green and yellow, TNT loaded. Did these have tracers?

Enjoy:

 

[DEADLINE222]

I am no lathe expert, but I would think that making an ogtive would be one of the hardest manual operations one could preform?

I machine the ogtive closet to it's final shape as I can, and then finish it off with several types of discs on my angle grinder -while turning in the lathe.

There are usually several hours of multiple, confortable couch sittings where I stare at the product, and compare it to the original. This particular piece went threw no refinements and looks exactly the way it did when it came out of the lathe.

It usually takes a few days to get it perfect, but on this one; I am going to leave it alone as is.

 

[DEADLINE222]

Here are two other projectile I have machined parts for.

The 75mm M61 required a new, pressed on ballistics cap(made by me), in addition to the windshield. -this was a chore. If you look closely you can see the three press marks on the ballsitics cap.

The 37mm M13 only needed the windshield. However, it is pressed on and not screwed on as the original, as I have yet to master threading on the lathe.

The all original 75mm M61A1 (with the exception of the rotating band) is here for the laughs.

 

[Lou]

Kick ass work.

My opinion,just from having seen under a number of ballistic caps,they are machine stamped/pressed.

Yes,some of the 57mm M86s had a tracer. There are two base plugs that Ive seen,one flat flush,no tracer pocket and another that had a tracer pocket machined into it. Niether of those two were marked as far as I could see and both were for empty load,black painted M86s. It also carried base fuze M72 "green painted projectile""that served as a impact fuze and tracer element. Of which I would love to get my hands on,but have never seen.

You do good work sir,,,,,

 

[Slick]

Wow! "kick ass & good work" DITTO

The two identical 90MM caps I have were both pressed. Would assume that to be the more common industrial process involved in crafting these sorts of things. For the consistency that's in it.

Regardless, your efforts are superb.

 

[Lou]

I had the thought maybe to ask for a couple of the 57mm caps,but I know theres no way in hell I could afford it,,,,,,

 

[wichitaslumlord]

The finished product looks great. Very nice work! Pat

 

[HAZORD]

Due to the quantities of windscreens that were needed, they ver most likely drawn in a number of steps with annealing in between. They would not have been machined or spun.

All U.S. tank and antitank projectiles (armor piercing) have tracers, so the gunner can visualize where he is hitting. Non explosive APCpped projectiles had base plugs in the explosive chamber with a hole drilled for the tracer. The Explosive filled projectiles had a tracer in the fuze, 57mm, 75mm, 76mm/3 inch, and 90mm.

 

[SG500]

Great work Deadline 222, what you've made looks excellent.
Dave.

 

[Falcon]

Great work. Just a word of caution: be careful with that grinding disc dust on the lathe bed. If the carriage is moved along over the dust it is very bad for the bed.

 

[DEADLINE222]

Yeah, my lathe is very dirty. I consider it somewhat of a practice tool, since someday I plan I purchasing a much bigger and powerful lathe to handle 90mm and up.

Also, being from Harbor Freight, I do not consider it to be the most accurate tool in the world.

Hah, and with that said, I acctually have a video where I am unloading a ANM-64, 500 pound bomb casing from the back of my car. Using a ramp and/or slide I did not think the casing would move once it was on the ramp, and out of the trunk. I was wrong, and the casing shot down the ramp with tremendous speed; flying across the garage floor and hitting my lathe table and knocking it over, destroying most of the front controls.

Lou, I really do not enjoy making windshields as they are a real piece of work, but PM me and we may talk.

Here is the finished cartridge. OD green with yellow markings to indicate TNT/explosive filler, per TM 9-1901.