I talk about this with customers and knowledge seekers all the time. Caliber is a question that really doesn’t make such a huge difference as most cartridges are throwing the lead in a similar trajectory until you get into some extreme differences. So your old .30-06 vs .270 question is moot. Most guys get the bigger caliber and then shoot the cheapest bullets through it. This is not advisable. Your bullet selection plays an important, critical part. Because the rifle doesn’t make the kill. The bullet does. You need to match the bullet to what you want to kill with it.