I am developing a load for a Ruger#1.(26 inch barrel) (YES, I know Ruger#1s are not a Long Range Rifle) 7mm Rem Mag. Winchester Case(new) CCI250 160 gr Accubond Retumbo My chamber has long throat. The lands measure 3.521. My OAL is 3.506.(.015) off the lands. I did a ladder test earlier this week and confirmed that around 70-72 gr was where I was getting tightest grouping. This morning I went to the range and shot a few 3 shot groups. When I got to 72.5 I was getting around 2940 fps. No pressure signs. This was after I had fired about 9 shots. I usually try to let the barrel cool a lot between groups. The barrel was probably still warm. So I decided to clean my rifle. I dry patched and fired off 1 of my 71 gr fouling rounds. I then shot my 72.8 gr 3-shot group. Much to my surprise the velocity was well over 3000. I had 1 shot @ 3063, 1@ 3064, and 1 @ 3080. 1 of the cases had a slightly cratered primer.(Not bad just a little raised). So obviously that sign coupled with the speed shows I am probably a little over the max. Both of these groups showed MOA potentional. (2 rounds @1/4 inch and 3rd hitting 1 inch away) the 3rd shots were probably be my fault. So now the question. When a barrel is clean and cold will it run 50-70 fps faster?...and can I assume that the 72.5 gr load may be actually closer to 3000 fps when it would be fired in a clean cold barrel. I am going to confirm this in next couple of days. This is an early 70's Ruger so I suspect it isn't the best barrel. The rifle will shoot MOA when shooter does his part. 1 day I plan on re-barrelling it but it will have to wait. I shot a Mule deer buck at 328 yards last Fall(1 shot), and I can hit steel silhouettes out to 500 yards with it so I am happy with it as a 400 yard deer rifle. Seems this rifle is very tempermental. I think I will load a bunch of 5 shot rounds.(starting at 71.5 and slowly working up with 72.5 as a max.) I will make sure to leave the barrel cool more and clean and foul in between each string.