Can any one tell my why they recomend the TNT for the 222 , can't understand it .
Thanks Bill

The tnt has a pretty soft jacket and probably can't take the speed of the swift. I played with it in a 300 wby and it couldn't take max loads like a nosler bt could. It's still a good bullet for most your "regualar speed" cartridges.

There is a warning on the side of the tnt box that states not to exceed 3500fps as it will explode in thin air.

Larry

You can use them Bill, just don't exceed 3500fps by much. I used to have a Swift & played w/ the Sierra 50grBlitz a bit @ speeds above 3500fps. Sometimes the bullet made it to the target & sometimes it didn't. I can only assume the bullet jacket came apart in flight & the bullet spun off to who knows where.

Ever hear the phrase going like a blue streak?
if you drive a Speer TNT too fast you'll get to see one....Atomized lead in mid-air forms a blue haze.

Between the heat from combustion of the propellent plus the friction of the barrel heats the bullet to near the melting point of lead.

It has been suggested that:
Friction through the air heats the bullet further and the rotational forces spin some of the lead up and out through the nose, what happens after that is equally interesting.

First, do you know how to identify Raw eggs from hardboiled ones without opening them?

Set them on the countertop and spin them.
the hardboiled egg will spin smoothly a raw egg
will not and will slow rapidly.

The same thing happens to a bullet when the core melts, this results in spin loss and then instability and the bullet basically goes into a flat spin and blows the molten core out.

In extreem cases the jacket will simply break up without a solid core to support it.

ANY of these things can happen and a bullet breaking up in flight is sometimes a combination of these factors

And in any case the bullet goes nowhere near point of aim, even if it does not break up.

I've actually found empty (distorted but intact) bullet jackets on the ground downrange after some visible
mid-air failures when testing some really hot handloads in a 25-06.
the bullet? 75gr Hornady Hollow point
The propellant? Norma MRP (Now known as RL-22)

I was playing "how much can I force into a neck sized case
without flattening primers" I won't say how much, but it was a lot.... (Hot enough that cases used that way five times developed loose primer pockets, IOW way too hot)

Think that's bad? I once had to help a friend remove
part of a bullet jacket from the barrel of his 223rem Ruger M77. Seems he was trying to drive hornet bullets too fast, melted one and blew the base and core out of the barrel and the cylindrical portion of the jacket stopped about 4" from the muzzle... fortunatly he realized something was wrong from the "odd report" (and lack of a hole in his 25yd sight-in target) and didn't fire another round...
Fortunatly it came out fairly easily with a 6mm cleaning jag that would just BARELY fit through the 22cal bore.

It coulda been ugly... or should I say "even uglier"?

AllanD

Rate of twist has as much to do with how well they hold up as all out speed. They will hang together in my 22-250 1-14 twist at 3700 fps. but in my old 1-12 twist same load destroys them.