When I first heard about Remington Leverevolution ammo, I thought that pointed rubber tip was the answer to improved trajectory and increased range on the 30-30 and I was very eager to try some.
Every rifle reacts differently to different factory loads. So one Marlin 336 may do well using the Leverevolution and another may not do so well. My Marlin 336 shoots 1" groups at 100 yards using Federal Premium 150 grain Sierras. I tried Rem Leverevolution and man I was really disappointed because the group grew to about 5". I've tried several times and the results are always about the same. So I won't use them in my rifle.
BTW, I use a Rem 700 30-06 with Fed Premium High Energy 180 grain Nosler Partitions for elk. Although a lot of elk have been killed with the 30-30, I don't use a 30-30 for elk because I don't want to give up 100 yards of range. IMHO 200 yards is max responsible range for 30-30 on elk. I'm sure some other will dispute that and some will claim they have killed elk using 30-30 at much longer ranges. But that's my limit.
