I've been doing some load development for a new to me M1 Garand. It is a beautiful 1945 Springfield Armoury. I'm getting a consistant issue of having two distinct groups within a single 5 shot group. It seems like almost every load I try will have 3 rounds in one "group" with the other 2 rounds in another group usually about 3 inches apart. The separation is mostly verticle although some have a bit of lateral in them as well. Some of the loads look very promising with 3 and sometimes 4 rounds in a group of an inch and even less, then 1 or 2 rounds in another nice tight group but 3 inches higher or lower. Looking for some clues as to what may be causing this. Due to the range being busy and my spotting scope not very good I haven't determined if its the first or last rounds that are spread either. I have checked the receiver/stock fit and it seems nice and tight with no play. As well I don't think it is the shooter as I shoot other rifles with similar sights on the same trip to the range with nice 1 1/2"- 2" groups. I should add shooting is done from a solid bench with a good rest.