Been lurking for years, finally was able to get registered, stupid computer, anyway, I have been casting my 45acp and 9mm rounds for years. Recently, started casting for my 45LC, so I am not unfamiliar with the casting process. So here we go, I wanted to cast some rounds for my 308 Win bolt action rifle, Ruger American, just for practice. I researched extensively with several other casters and the internet, Youtube, etc... Was able to put the rounds together and everything seemed great. Until I took them to the range for testing. I was shooting at a 9" target at 75 yards. Out of 16 shots, I only hit the paper 5 times. I was stupified!!! I thought I have messed up my scope, so I tried 2 factory rounds. Put both of them within 1" of the bullseye. So It was not the scope. Am very frustrated!! The rounds themselves are 160 grains. sized to .309, tumble lube design, using 41.5 grains of IMR4064. They chronoed at 2534 fps. I can't think of what might be the problem. The factory rounds that I used were also reloaded by myself using factory bullets. I did notice that when I tumble lubed them the 2nd time, some of the gas checks came off. I am wondering if perhaps the gas check is coming off in flight, causing the inaccurate hits. Would it be better to slow down the rounds and go without the gas check?
Any help would be greatly appreciated!!!!!