I agree M855 are considered ball ammo by the military. Unfortunately, that is one of the ammo types specifically targeted by this rule change.
Also, a steel core is not a requirement under the current AP definition. It is a projectile OR projectile core. Plus it can be made entirely or in combination from any of the listed alloys (see BATFE definition below). The BATFE reasoning for going after the M855 ammo does not make much sense, which is why this rule change is very suspect.
18 U.S.C., § 921(a)(17)(B)
•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
•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.
Once again, I point out that those two lines you cite are no applicable to M855. In particular, the first one. There is no alloy of the metals you list which “construct entirely” the round. The majority of the rounds mass is lead.
The projectile core is not constructed entirely of steel. Steel is ~15% of mass, and it’s not alloyed or compositionally part of the whole core.
The projectiles jacket is not 25%+ of the mass.
While they may get their way rule wise from bureaucratic inertia, their argument would never stand a legal interpretation of the rule (with competent and uncorrupted judiciary of course).
Heck, you could probably make a real AP round that would pass this definition as non-AP and exceed M855 penetration specs by having a 76% hard lead alloy or bismuth core and 24% jacket of something like titanium or tungsten or chro-moly steel...
The proper way to explain it to a non-smoker is that Obama is specifying this, this, and this (implying that he is being, um, "selective" and "commonsensical" - - lie, lie), when in fact he's going after all ammunition of every type.