I am a first time poster to these threads but a long time viewer. I am sorry if this topic is covered in another thread. If so please direct me there. Here is what I have, I have a FN mauser action, ER Shaw barrel, Bell and Carlson Medalist stock, Huber concepts trigger, Leupold varixIII, and Leupold mounts and rings. Chambered in .284 Win. Barrel is free floated. I have loaded and shot 140 grain Nosler partitions, Berger VLD hunting, and 168 grain Berger VLD hunting bullets. I have achieved the best groups with the Berger VLD's. During load development I went to the range and shot very nice groups and found the seating depth I wanted with the Berger 140's. 0.41 inches at 100 yards with 3 shot strings. Here is the problem... Before I shot the three shot strings I actually had to shoot a warm up shot and then waited exactly 4 minutes in between every shot for the three shot group. POI change from the first shot and the three shot strings ranged from 1-1.5 inches. I attributed this to being able to keep the barrel temp very consistent etc. Didn't think much of it. I got some of the rifles favorite length loads loaded. I decided to go back and zero my rifle using 1 shot groups with 20 minutes in between. They were all over the map! 2-3 inch groups. I will only be using this rifle for hunting purposes and the first shot obviously is the one that counts. Am I not waiting long enough (20 min.) for the barrel to cool down in the one shot groups? Or is there another issue? I have not tried waiting an hour etc. Very disheartening as the rifle and myself are capable of shooting 1/2MOA once it warms up! Sorry for the novel just wanted to let everyone know the whole story. Thanks for any help of direction?