As others above mentioned, a bigger, more powerful caliber is called for. Here's a story for you.. 2 weekends ago I went hog hunting with my .308. The place I hunt is over-run with hogs and it is rare to ever see just one hog at a feeder. So, when multiple hogs are present, I always wait to shoot until 2 are lined up. That way I kill 2 hogs with one bullet. Well, on this day, the 2nd hog was only hit by bullet fragments as I spined the first hog and the bullet fragmented. The pieces that hit the 2nd hog took out his back legs, but for all intent and purposes-he was doing his very best to get out of dodge dragging those useless hind legs. I thought here's a chance to see how well my .40 will do on actual flesh. I walked up to that hog within 5 feet, and fired a 180 grain Speer Gold Dot into the chest cavity. This pig is small at about 50 lbs... It crept crawling, but was now picking up the pace! I fired a 2nd shot into the chest cavity which was now bleeding, but not as much as you would hope. That shot really got the pigs attention and he started to corral those hind legs to work again and he was almost up on all 4 legs! I fired a 3rd shot into the chest cavity which knocked the back legs down again, but still that darned pig was crawling toward the wood line! I finally got between the pig and the wood line and placed one right between the eyes which finally (Thankfully!) put him out for good. When we cleaned that pig, we found that only 1 of the 3 rib/chest shots actually penetrated the chest cavity. Yes, he would have died (slowly) from that shot but I wanted him dead right then, not a day or so later. The other 2 hit ribs, and instead of breaking them, the bullet simply followed the rib between the skin & rib. All 3 bullets when recovered showed ZERO sign of deformation. I can put them right beside a new, unfired Gold Dot and the only way you would know which ones were fired would be to look for the rifling on the bullet body.
So, please, if you want the animal to die quickly-choose another caliber. Or, plan on firing multiple shots as quickly as you can pull the trigger (empty the gun) and hope that you hit something vital that will stop the animal before it gets away.. Those are my thoughts do with them as you wish.