At 30 yds, either one will work. There is no dead, deader, deadest- only dead. The .17HMR does carry more energy than the .22 LR (@ 30 yds, 17 HMR 208 ft lbs, .22 LR 114 ft lbs) it shoots flatter, and it costs more (about $13/50 rds, vs $2.50/ 50 rds. The 17 really comes into its own for very tight groups, and at about 100 yds.
What we have here is... failure- to communicate.