I'm very new at reloading so bare with me. I've been trying to build up a good load for my 338 lm. Its a 26 inch barrel 1-9.3 twist. I've been shooting it at 100 yards trying to develop an accurate load and have come up with nothing be horrible groups. 3+ inches. It has been extremely erratic. I've stretched it to 200-300-and last night 400 yards. with the same results. Initially thought it was the bullets. I was using 300gr accubonds and just figured the gun didn't like them. Using lapua brass I started .020 off the lands and 90 gr of retumbo. Then worked my way up to 92 gr and just felt like something wasn't right with the bullet. Again, I'm new at reloading so I was like "whats a few more grains of powder going to do"? So I switched to bergers 300gr EH. I started all over and began at 89 then 90gr with the same horrible groups. Well last night, going after some 10 inch steel at 400 yards, I was able to hit it but at 2.6 mils high. Using noslers load data I thought I should be around 2600 fps which should get me around 1.9 mils at 400 yards. Only guessing, I'm actually around 2300 or less. What could be the cause for this low velocity? Could this also married with my crappy groups? I have a feeling its all tied together but i don't know where to go next.