Shaman ,if you want more speed or power get a 300 Savage or a 308 Win. Having one of your 30-30's reamed isn't the answer, put a scope on the 340 ,put a receiver sight on one of the 336's and leave the other with barrel sights . Work up a load that works in all of them ok, so no matter what gun or what box of shells you grab heading out the door it will work perfectly every time. Just think it could be that damn simple. ONE load 3 guns and they all work perfectly everytime now that's an outcome to shoot for.(pun intended) MB
