180 Grain 30-06 Federal Premium Nosler Accubonds

[Rol Page]

I am finding a variation of 158 fps between lots of Factory Federal Premium 180 grain Accubonds in my 30-06.  June 12th the average velocity for 3 shots was 2,760 fps.  Today, June 26th the average for 3 shots was 2,602 fps.
My hand loads are more consistent in velocity, but running about 2,660 fps average day to day.
Weather was similar, maybe a little warmer today.
My rifle is a Remington 700 CDL with a 24" barrel.
Any insight will be most appreciated.  Thank you in advance..  Rol

[charles p]

Could the condition of the barrel cause this?  Would a heavily fouled barrel increase pressure - or maybe decrease pressure.  Someone smarter than me may be able to assist us.

[shot1]

If you are shooting different lot numbers of factory ammo everything is NOT GOING TO BE THE SAME. The factory uses a different propriety powder made just for them to their specks. Different lots of powder and primers etc. will produce different results. That is why bench rest shooters and accuracy nuts like me handload. We purchase our components in as large a quantity of the same lot numbers as we can to keep everything as close to the same as possible. 

[Lloyd Smale]

like was said differnt lots can  vary.  Factory ammo can vary even in the same lot. I once pulled some bullets on some corelock 165 280 rem ammo to get the brass. I had no use for a 165 round nosed load and was given 10 boxes of them.  I was curious what powder rem used so i figured id weight 5 of them and look in a loading manual to see about what powders would give the speeds that ammo gave. They varied so much i ended up weighting 5 for each box. this was all the same lot number and the powder charge in that ammo varied as much as 5 full grains case to case. Funny thing is that one of my 280s shot that ammo into an inch at a 100 yards! Im sure though that when the range got out past 200 groups would open drasticaly with that much variation. Goes to show a guy though that worrying about a .1 of a grain differnce in charge weight is kind of silly.