Making Full Metal Jacket bullets

[Danth]

I understand inserting jacket / core up-side down will produce a full metal jacket bullet, but the bullet will have an open base. Are there any detrimental effects in making a bullet in this manner?

[uncle dino]

You can fold jacket over the base over by reversing bullet in point form die to start fold. Core seat , reverse, point form. There are several ways to fold copper over base. This works best with short ogives. D

[Ballistics in Scotland]

Certainly not when the rear edge of the jacket turned over, but do you mean when it isn't? Probably not much, but it sounds like a good case for having the bullet core-bonded.

You might also find that the rear of the jacket, when it isn't turned over, becomes slightly uneven. Filing it square isn't the perfect solution it might seem, as it is likely to have got uneven in length by being uneven in thickness. I think it would be best to turn the edge over. You probably don't need an extra die for this, just an extra stage in the process, by very slightly boat-tailing the rear of the bullet in the ogive, and then finishing off with a flat punch on the base.

[Hardcast416taylor]

I recall reading about this practice being done in the mid part of the last century by professional hunter/guides in Africa if their ammo stock selection was running low or down to just FMJ ammo. They would pull their FMJ bullets and reverse them in the case. At close range accuracy beyond that of a charging lion wasn`t that important.Robert

[rickv100]

It can actually be an improvement. The bullet bumps up in diameter on firing to the diameter of the barrel. Good for military use when shooting out of worn rifle and machine gun barrels.

[Reverend Al]

Is your concern about having the lead core exposed at the base of the bullet? It hasn't been a big problem for over 100 years for military fmj bullets and they've loaded millions of them like that, but if you want to try it you could add a gas check to the base of your core and then swage the bullet and end up with a sealed base? Sounds like an unnecessary step to me, but you could try it if you like?

[Huvius]

The only FMJ boolits I have goofed with are these .358s made with a regular cup, a 32cal lead ball and a plated 8mm Nambu boolit on top.
Will punch nice round holes in paper but I bet they would fall apart on an animal since the cup edge is facing the front. I expect the lower half would just peel back like a banana.
I tried to go backwards but the jacket is too thin and ruptured the nose.

[GONRA]

GONRA makes 48.5 grain (and under) FMJ .380 ACP Boolits for .380 ACP Seecamp Pistol shootin'
on my Corbin CSP-2 Mega-Mite press with a mix of Corbin and my tooling.

Corbin die made to my specs, usual punches techniques per above FMJ posts.
Use .500 or .442 inch looong 38 cal. jackets.
Small lead "core" in front forms the ogive. (Made a "stripper" to seperate jacket and punch when it sticks.)
Corbin's "blue plastic ball" fills bulk of the boolit.
Just fold over and seal base per above FMJ posts.

These shoot Just Fine (no keyholing!) with 3.0 grains 231 powder.

[GONRA]

GONRA’s Jacket / Punch stripper for my Corbin CSP-2 Mega-Mite press.
(Maybe you've seen this stuff zillons tymes before, but couldn’t find it on this website.)

Two 5/16-18 bolts 3 1/2 or 4 inches long,
1 inch wide hollow square extrusion stock machined to suit,
(1 1/2 inch gap, leaving .220 inch wall height "U" in center,
also 3 3/4 centerline spaced 5/16 holes for bolts, central hole for Corbin punch),
2 return springs from Sears Hardware, nuts, washers is all there is.

1 1/2 inch diameter thick "fender washer" must be bored out for a selective fit on the Corbin punch.

This cured “jacket sticks” whilst using the 356 die, Corbin .442 inch long 38 cal jackets
and 356 C 330 punch, further modified by me. Verks slick!

Next post should hava foto. Crossyer fingers…

NOPE! Still haven't outgefiggered it all. Sorry.

[Sasquatch-1]

I have seen (but never tried) where a gas check is placed in the opening before point forming. Makes a completely encase bullet.

Looked for the video but couldn't find it.

[Sasquatch-1]

Here is a video on how to use gas checks to fully encapsulate your round. This doesn't show all the steps but gives you an idea of how it is done.

https://www.youtube.com/watch?v=PLtFCRtwRN4

[just bill]

This is one of those times pictures would just send the post over the edge.