Sorta. Depends what you mean by "penetrators".
18 USC 922(a)(7) bans the manufacture or importation of armor piercing ammunition.
18 USC 922(a)(7) said:
It shall be unlawful—
....
(7) for any person to manufacture or import armor piercing ammunition, unless—
(A) the manufacture of such ammunition is for the use of the United States, any department or agency of the United States, any State, or any department, agency, or political subdivision of a State;
(B) the manufacture of such ammunition is for the purpose of exportation; or
(C) the manufacture or importation of such ammunition is for the purpose of testing or experimentation and has been authorized by the Attorney General;
In addition a federal licensee may not sell or deliver AP ammo.
AP ammo is defined in 18 USC 921 (a)(17)(B):
18 USC 922 (a)(17)(B) said:
The term “armor piercing ammunition” means—
(i) a projectile or projectile core which may be used in a handgun and which is constructed entirely (excluding the presence of traces of other substances) from one or a combination of tungsten alloys, steel, iron, brass, bronze, beryllium copper, or depleted uranium; or
(ii) a full jacketed projectile larger than .22 caliber designed and intended for use in a handgun and whose jacket has a weight of more than 25 percent of the total weight of the projectile.
9mm certainly fits the "may be used in a handgun" part, but the definition is very specific. If you were to make the projectile core out of some other, dense, material it wouldn't fit the federal definition of AP, and as such isn't banned
at the federal level*. Performance would depend on exactly what you used.
I suspect you don't see 9mm AP projectiles sold because to make one outside the federal definition would be prohibitively expensive, a niche market, and a PR nightmare.
CANNONMAN said:
As far as pistols, are you allowed to sell, buy or own them
I assume you mean AP pistol ammo. Obviously we can own, buy and sell pistols.
If you came across some AP 9mm that predated GCA '68, you could possess it, and as long as you are not any level of FFL, you could sell it. If it were only projectiles you could not load them into live cartridges (manufacturing) I honestly have no idea if any legit, legal 9mm AP made it into the country or is still floating around. On a practical matter I would hate to be trying to prove some steel core 9mm I had was old enough.
*I only looked at, and quoted, US federal law. State laws can, and do, vary widely and you would need to research your local laws before any attempted loading near this line.
**The quoted USC is mirrored in 27 CFR 478.37.