Is there one out there? How about some homemade ones? Would a .50cal bullet for a pistol be the same diameter as the Powerbelts? Could they be loaded with a over the powder wad?

What you're looking for is a slip fit conical... I would try R.E.A.L. conicals or some No Excuses Conicals. I am not sure if you could put a .500 diameter projectile into a sub base and get good accuracy although you could try. I have some 440 grain .502 diameter bullets that I thought would do real well and they were a disappointment to say the least.

How did the .502's load? Would they stay on the powder?

They stayed on the load all right but the accuracy was terrible. I tried them out of three different inline rifles and with a lot of different powder charges but could not get them to group. I thought I would try them in the 1:48 twist rifles this summer and if they do not shoot, then I will melt them down and make roundball out of them...

The Buffalo bullets and ballettes are both of the same type.

From what barrel rifling and caliber?

Sabot's in 200-300 grain.
Conical's from 300-500 grain.

There is a close copy to the Powerbelts out there. They are made by a fine bullet company & are less expensive than Powerbelts. They come in 250 - 300 - 350 grain. The two smaller grain sizes are 15 for $8.78 and the big bullets are 12 for $8.78. Unfortunately, this store offers no photo.

Harvester Sabertooth ML Bullets

You probably already know this, but the hollow points are cheaper than the aerotips (20 per package instead of 15), so I use them for practice, and use the aerotips for hunting. Of course, they don't hit the same place unless you are really lucky, so you have to resight in when you change.

Wow T7!! $9 for 15 instead of $19 for 16? That's a no brainer. Have you shot these? Do they shot as well as the Powerbelts? I went to the mfg website and looked at the bullets they look well made. The petals look a bit funky in the pic but the recovered bullets made me not worry about that.

Be sure and keep us posted as to how well they shoot if you get any of them. Next time I place and order from Midsouth I will have to get a pack or two...