In my case...
Oklahoma has small deer. I hunt my own property and generally I harvest deer in the 125 pound range. And shots are short... 35-50 yards is the normal thing. You can't even see 100 yards through the brush so that's no temptation.
I love .357 SIG and it is my normal carry round. (HK P2000 LEM) I reload the cartridge but my carry load is what the Air Marshal's carry... Speer 125 grain Gold Dot. My Air Marshal (old Army buddy) talks to other AM's and some of them have used the cartridge for deer hunting. He said some had poor results... inconsistent expansion? No details.. not sure why that would be... it kills everything I shoot with it. So I decided to call MGM and order a custom T/C Contender barrel. I went 12 inches, stainless, cool spiral flutes, full bull. Since I was going to use it to shoot deer, I decided to try the Hornady 147 grain load. Burris scope. It shoots great on paper, puts one bullet on top of another at 50 meters.
But... I've only shot one deer with it this year and "something went wrong." I hate to believe it was me... but I guess it probably was. Decent buck walking right to left. Shot was fired at 50-60 yards. Held behind the front leg, midpoint vertically. Seemed like a clean shot at the break. He did the jump straight up in the air in a C shape thing. Hit the ground, took off running. Like they always do. Went about 40 yards to my left into heavy brush. Then I swear he sort of leaped sideways and fell on his side. I saw feet. I started making everything safe, and climbed down the ladder. Took extra equipment off myself, then started trudging out there. Couldn't find him. Went back to the stand and climbed up... marked in my mind exactly where I saw him go down. Went out there... nothing. Called my wife to come out and bring one of the Malinois. The dog hit on the exact spot where I saw the deer go down. The dog found two good splashes of blood there. But no deer. We searched in circles and around and around for literally hours upon hours. Never found the deer. I hate it... that never happens to me!
So I'm kind of on high center on the cartridge out of the longer Contender barrel. Obviously it gave great penetration and my expectation was that the higher velocity would make expansion even greater... so it should work fine. Maybe it was a fluke and I could shoot ten more and never see that again. Or maybe I should try the standard 125 grain load instead? I know I would get some violent penetration out of it coming out of a 12" barrel... but then I'll be wondering about penetration.
I love the cartridge and use that barrel for lots of small and medium varmints around the farm... but I sure would like to be able to use it for deer hunting from a stand. Very accurate, virtually no recoil out of that scoped barrel. I don't know...maybe it was strictly a shot placement error on my part.. .hard to make a conclusion based on one animal... but I also hate to shoot another one and have another less than clean kill! My .445 Super Mag Super 14 Contender barrel wouldn't do that! Or my .357 Herrett or even the .357 Maximum... but there's the whole issue... you move up to higher velocity and you just blow right through both sides of the ribcage of our small deer.... not sure that really improves "right there" killing power. Larger diameter, sure... bigger hole lets out more blood, lets in more air.