It seems to depend on the specific rifle. I can't get accuracy with powerbelts above 95 grains of 777 but my brother with the exact same rifle (Omega in SS) gets great accuracy with 110 grains.

However, 90-95 grains of 777 is equivalent to 105 to 110 grains pyrodex, so that is plenty of powder for what I hunt (elk out to 100 yards)

I have heard that pyordex is a little more forgiving with powerbelts.

I am going to try American Pioneer Powder with cooler 209's (cci's) and see what kind of results I get. I like the clean up of cleaner powders vs pyrodex and I like the ease of using powbelts, so it is worth figuring out the accuracy issues.

Some, like bigcountry, like to push the envelope both in power and distance, but for me anything over 110 grains equivalent kicks the fire out of me and I think my accuracy suffers. Since I am limited to conicals (Colorado) and don't shoot over 100 yards because I only use open sights, powerbelts fit what I need to a "T".

So much for accuracy performance. However, I think the jist of the original question was terminal performance. And I do remember hearing several complaints in that regard. The first one was a guy that killed a cow elk and he was dissatified with them because they did not exit and give him a blood trail. After much searching, he foud the elk 20 yards from when she stood when he shot. He called this a "failure". I asked him at what point of the elk dying within 20 yards of where she stood constitute a failure.

The second was a guy that said he had a broadside "double lung" shot on a bull elk with a powerbelt but never found him. I asked him how he knew that he had gotten a double lung shot on the bull, since he never found him. I contend that if he had actually hit the bull with a broadside shot and double lunged him, the bull could not have gone very far. He didn't have an answer for me. I suspect he hit him too far back.