Quoted:
Hey there,

Oddball Ideas here. Was flipping through one of the latest firearms magazines earlier, reading an article on a 5.45 upper, when these thoughts came to me.

Does anyone make a .224 bullet with the internal design of the 5.45 military round?

You know, a bullet designed on the edge of stability with a hollow tip, lead filler, and a steel penetrator that shifts forward and upsets the round whenever the bullet encounters something dense (a.k.a. human flesh).

No, they do not. They do make bullets with equally impressive terminal ballistics, though! And a greater range of styles, performance parameters, and weights!

Barring that, has anybody necked a 5.56mm casing down to 5.45mm and loaded it with Russian(etc.) 5.45 military bullets, in order to alleviate magazine problems? 5.45x45mm?

What would be the point? For one thing, the ogive of the 5.45 bullet is a lot longer and it probably could not be loaded to magazine length in an 'x45mm casing. Also, the reason why there are so much interest in the 5.45 round is that it's cheap factory made ammo that can be made to run in a 5.56 and has similar performance. Take away the "cheap factory" part and there is no point. If you're going to go through all the hassle to load 5.56x45, it doesn't make any sense to try and use 5.45x39 bullets with all the .224" projectile options out there.

Can you even get those bullets in component form?

No, they are a military production item, and I don't believe they're even made any more. I believe they've replaced the 7N6 round we're buying as surplus with the 7N22. They're not commercially available. .