Someone on falfiles gen weapons disc was asking about 47 or 74, and somebody put a whole new spin on the penetration and delivery of energy from 5.45:
I have a SAR-2 and really like the little 5.45 round. It is just too darn bad the Ruskies didn't standardize on a .224" bore diameter and we could really have some fun with them. I would love to play with one in a .223 size bolt action rifle or maybe a Contender rifle. But I would have to be able to reload them and you can't do that (not yet anyway). The ammo is still so cheap that it is a great blaster in an AK.
True story that happened last week. I've got a stock pond up close to the barn. I _thought_ I totally shot it free of turtles a couple years ago. Haven't seen any little heads in a long time. But I just kept losing little ducklings. They had to be going somewhere. I went to look and saw a few very tiny little turtle heads but nothing that should have been a threat. A week went by and more ducklings disappeared. Exasperated, I carried a lawn chair, binos, and the 10/22 down to the pond. I ended up shooting quite a few little heads. One floated to the top and took multiple hits. That one was a snapping turtle (to my surprise). He was decent sized (about dinner plate). Maybe he was the one? I finally broke it off for the day and went inside.
The next morning I came out to check on the goats and couldn't believe the pond. It looked like a bunch of logs had broken off the trees and were floating. Closer examination showed six more floating snappers. And one of them was so frigging big he could have been on exhibit somewhere! Wow, he would have had no problem eating my little birds. But then they just kept floating and starting to stink. Hmm, it would be better to sink them and they could at least decompose under water. I went in the house and got the SAR-2. (Finally, relevance!) It was amazing. I was using the Barnaul 59 grain ammo (blue box). Every shot that hit turtle literally sent pieces flying way up in the air and over to the other side of the pond. I saw one complete leg from the really big one go at least 30 feet.
I came away from that experience with a very firm conviction that I wouldn't want to get shot with that round!