I have been getting my big gun ready to go shoot an elk, but am having a duhhh moment for some reason. I am loading 140grs of H50BMG in a 338-408Ct improved. Most everyone else in running 142grs. I shot one case 11 times and primer pockets are still tight so I know I am not way over pressure. The guys running 142 are reaching sppeds in the 3300 fps range. Here is my issue, it only takes me 11 MOA to get to 800 yards. Which id the .818BC is correct means my bullet should be running 3400 fps.
I know there is no way I am at 3400 fps. When I first realized that 11MOA was perfect for 800 I decided that my 100 yard zero must be off. This afternoon I confirmed my 100 yard zero, no problem there maybe 1/4 MOA high. My sight height is correct. My enviromentals are correct as downloaded and check via kestral. I am accounting for the 2 degree downslope.
I decided it must me the scope dialing. So a couple minutes after I confirmed my 100 yard zero I dialed up 20 MOA then shot at the same target. Using my NPR2 reticle the 2nd bullet hole was exactly 20MOA higher than the first.
I decide to try my 600 hundred yard target elevation was perfect there.
It has to be something simple I am missing. Any ideas?
If I do not find something soon I am gonna start tweaking BCs because I know this load is actually running 3200 avg.
