Hello. First time posting on this forum, bit very active on others. I am primarily a bolt gun guy, but I'm working on developing loads for a friend for his 450 BM for MI hunting. I wanted to start by saying that I do not believe that my problem is a reloading problem, I think and hope that it is a buffer weight problem. Here are the details of the issue and what I have done so far:
1. The point of impact shifts significantly between the first shot of any string and then shifts back on the third shot.
2. The shift is aprox 3-5 moa between the first and second and then almost returns to original point of impact from the first shot.
3. The problem has been consistent over two different 450 uppers onnthe same lower.
4. The problem has been very similar when shooting 250 grain factory ammo and 160 grain reloads.
5. The problem has persisted between two different scopes.
6. *** The problem goes away almost 100% if I load one round in the mag, put it into battery and shoot, and then repeat two more times. So, I am replicating the same feeding scenario with each shot.
7. All groups referenced are three shot groups.
1. Action open, 3 rounds in chamber, depress the varying button.
2. Second round is loaded automatically after firing the first.
3. Third round is loaded automatically after firing the second and the action locks back as mag is empty.