Size Nominal diameter Pellets/oz
0000 ("quadruple-aught") .38" (9.7 mm) 5
000 ("triple-aught") .36" (9.1 mm) 6
00 ("double-aught") .33" (8.4 mm) 8
0 ("aught") .32" (8.1 mm) 9
1 .30" (7.6 mm) 10
2 .27" (6.9 mm) 15
3 .25" (6.4 mm) 18
4 .24" (6 mm) 21

As U can see OO is a load of 33 Cal balls. The question is, will 33Cal lead balls kill a buck if hit in the lunges. The question should be, will I be able to hit a buck in the lunges at 50 yrds. with OO.
Based on your pattern tests, what do you think?