223 Brno query

Hi All. As some of you know I have a ZKK 601 brno. Im no expert on projectile weights so I'll leave this for experts to decide. I currently use SP 55gr remington ammo and always have. However, I've never shot a big bodied stag which I hope to do maybe this roar with this 223 (touch wood). Is going up to a 62-63gr going to make a hell of a difference on bringing down the big boys at close range (bush hunting only). Or can I even go higher? Twist rate is 1:12 I believe. I know shot placement is important and will let him walk if need be, but just been thinking can I go heavier and if so what are the advantages/disadvantages of doing so?

Cheers in advance.

Check your twist rate with a cleaning rod. 55gr is bout max for 1:12. You want penetration on bigger animals and the lighter 223 bullets aren't designed to give that. The copper ssts and the like may give the desired penetration but they don't have the oomph to do the business if they miss something vital.
I firmly believe that 1000flbs at the target is the min you should use on reds and above. You do hear of people dropping them with 222 and 223 but you never hear of the ones that got away with no jaw, or a football size hole in the shoulder that only goes in an inch or so.

Cheers Marty for your input. I have a pull through not a cleaning rod so can't check myself. I know exactly about the oomph factor and that's half the reason why I'm asking this question. Shot placement will be key in my mind as I don't take silly shots.