I use boosters in old #2 longs nearly exclusively now for coyotes, fox, and cats. They hold everything I get in them, and I got a bunch of old #2s for a song a few years back, so ended up with a great predator arsenal for not much investment. The boosters don't necessarily make them hold any more than without...long springs hold well by design anyway. The boosters made them a bit faster and stiffer though.