The weather finally cooperated long enough to get a ladder done. After the first 3 rounds were fired, it became obvious that I would be the weak link, not the rifle.
Date: 08-09-2010 7:15pm
Humidity - 60%
Temp - 85f
Pressure - 28.38
Range - 300yds
Bullet - 175SMK
Case - Winchester (virgin)
Primer - CCI200
Powder - Varget
Case length - 2.005
Length to ogive - 2.225 (10 thou off the lands.
Ladder - 42-45.5gr in 0.5gr
I had loaded up 10rnds at 42gr so I could zero and get on target at 300. The first round I fired was at 25yds. I came down 1.5 mils and left 0.5 mils using that bullet hole. The next shot I fired at 100yds. I hit high, so I came down 1 mil. I'll get that 25yd zero thing down at some point. ;) The next shot tore the center out of the target. Three rounds, and I'm zeroed for 100. I took another shot at the 100yd target just to be sure I was there. The shot landed just to the 8 O'clock tearing the hole a bit bigger.
I dialed up 1.3 mils and took a shot at the 3" target I had up at 300yds. I neglected to take the velocity decrease into account, and hit a bit low. I went to 1.7 mils and put one in the 3 O'clock position on the target. There was a bit of wind twisting around behind the corn and my buildings, so I knew I'd have a little lateral movement today. I could have likely come .1 left, but I left well enough alone and started the ladder.
1) 42gr - 2372fps
2) 42.5gr - 2400fps
3) 43gr - 2455fps
4) 43.5gr - 2477fps
5) 44gr - 2495fps
6) 44.5gr - 2519fps (very light primer cratering)
7) 45gr - 2545fps (slightly sticky bolt lift with primer cratering)
8) 45.5gr - 2543fps (sticky bolt lift with increased primer cratering)
The results absolutely floored me. No other ladder I have ever run in a 308 has ever looked like this. Even when taking steps as large as .5gr the vertical spread amongst the top charges was less than 2" at 300yds. I stood there in front of the target with my mouth hanging open long enough for a few hundred mosquitoes to bite me. Never have I see a rifle this tolerant.
After the ladder, I let the rifle cool and then fired a 4-shot group using the remaining rounds at 42gr. It measured 1.4" at 300yds. It is likely that the rifle will shoot better with fire formed brass. I'm speechless a this point. This thing makes me look like a friggin chump when it comes to shooting ability. Every single bullet on the target tells me the precise story of what I was doing when that shot broke. I'm truly humbled.
William Roscoe, you have a talent. A gift from God I would say. There are a lot of gunsmiths in the world, but I have not owned a finer precision rifle than this. Never before have I seen a rifle print a group like that during a ladder test. Ever. It does EXACTLY what I tell it to do. This rifle as a complete unit is the most robust and smooth firearm I have ever had my hands on. The surgeon 591 is without equal.
Next, I would ordinarily load a ladder in .2gr increments... but with this rifle it will do me absolutely no good. So I'll probably just load up 20 at 44gr and launch them through the chrono to see how the ES and SD are doing.
I anxiously await the next window when I can get the chronograph out without getting it wet.