Difference between FMJ and copper clad...

[Quack Addict]

I've been reloading for several years and have loaded rounds for my .223 using "FMJ" bullets. One of my favorite target loads for the 223 includes a bullet which has an exposed lead base encased in a relatively thick copper jacket. I am pretty sure these are not SS109, but they are similar profile.

I have loaded FMJ bullets for my 40 S&W that were plated with copper, all the way around. I think these are referred to as "copper clad".

Question... What is the correct definition for FMJ - Full Metal Jacket -- a bullet with an exposed lead base (thicker jacket) or a copper clad projectile with a jacket only a few thousandths thick? Can a bullet with an exposed lead base truly be considered a FMJ?

[Huntsman27]

There are plated bullets out there, its a cost effective way of bringing bullets to the market. Instead of using copper guilding metals [much thicker] the electroplate is cheaper for them to make bullets with. With the costs of copper and brass skyrocketing, manufacturers will surely be looking for ways make cash with alternatives. Wolfs Bi-metal bullets are one example of this. Cheaper than FMJ copper guilding, and lets them bring their ammo in below what Win/Rem/Fed and sell a lot more.
As Rugers comment shows both styles of bullet can be fully encased or have an exposed bottom. The Jacket really only need cover the cone of the jacket to be FMJ.

[alex-v]

Originally Posted by Ruger1

Not sure what the difference is between "FMJ" and "Ball ammo."

The "ball ammo" terms goes back about 100 years and refers to the standard bullet profile that is still used for the 45 ACP. The rounded nose fed up the feed-ramp without hanging up. When loaded in a 45 ACP case only the nose stuck out since the sides of the bullet were inside the case unlike many revolvers bullets. This makes it look like a "Ball".

These days many of the 230 grain 45 ACP RN bullets are copper jacketed. The ball look to the loaded round is just like the older style lead bullets so many will refer to copper jacketed as ball ammo.

It is the profile of the bullet and not the materials.