That's a discontinued .45 ACP bullet. The price is OK, but not great. If you want plinkers go for it. I wouldn't use them for hunting anything but small game because I just don't know if they were bonded or not.

See the current Speer 45 ACP bullets here: http://www.speer-bullets.com/ballist...nd=0&firearm=2

You can click on the PRODUCT SELECTOR section where is says "45 Auto" and change it to "45 Revolver" to see the rest of their line for 45's.

If you do a google search of " speer 4479 bullet" you will only get "About 178,000 results (0.15 seconds) " hits as to what the bullet is. I think some were in the 178,000 hits/links you will find the answere to your qestions.

I also saw the guy had some sabots for a .54 cal. rifle that held a .451 cal. bullet. I was really interested in it but wondered "What's the point?"

I got an answer from speer.
RE: Speer Bullets-Ask Speer Form
This was a Speer .451 pistol bullet, 225 grain Jacketed hollw point, with a crimping cannelure.
Crap, as I was copying the email and I lost it. Anyway, They said it has been discontinued. Does anyone know what a crimping cannelure is?http://media.midwayusa.com/productim...667/667170.jpg Midway has the bullet for $26.39 so $20.55 can't be too bad.

A crimping cannelure is the groove in the jacket for crimping the brass case into. Usually cases like 9mm and 45ACP dont use that style of crimping. Its far more common in 45colt or other calibers used in revolvers so the bullets dont move under recoil from the previous rounds.