SAW/Rifled Barrel to Smooth bore

[627PCFan]

Recently I was traveling and got the oppertuntity to fire a Pre-86 SAW at a local range. All the ammo keyholed on the target, but the weight was 52 grain 223s. The rifling was virtually non-existent after years of daily shooting, so in esscence they had a full auto smoothbore. How does the ATF look at this? Once a rifled barrel, always a rifled barrel, regardless of condition?

 

[DoubleTapDrew]

I don't think it would be considered a smoothbore just because it's shot out. Aren't SAWs supposed to be shot with 62gr ammo?
I'd replace the barrel on it considering the last registered M249 I saw sold (a few years ago) went for over $40k.

 

[CoRoMo]

How does the ATF look at this?

It's a machine gun, period. It is not a rifle, handgun, or shotgun. The bore doesn't affect its classification. Neither does its barrel length, overall length, etc.