2 things, the group you mentioned works out to 1.2" wide and 3.6" long at 100m. Vertical stringing is usually a sign of breathing for you and bedding for the rifle. That load is too hot and it does put WAY TOO MUCH preassure at the gas port and will damage your opp rod by bending it in the wrong place!! It's also hard on the other operating parts of the rifle. The NRA has some wonderful data on thier webpage for the M1 as far as match loads. You might also find when you start reloading that 4064 and a 168 grain boat tail, hollow point match bullet will help cut down that group size a lot out at that range!
Scott
Scott




















































