OCW - 308

[QuiggyB]

Here are the results from a trip to the 300 yard range. This is .308 shooting berger 155.5 fullbore seated .015 off with varget from a 27" barrel. This is from once fired lapua brass that was neck sized only. It was pretty windy. The grid in that picture is 1/2". these shots were fired one shot from each group about 30 seconds apart then I let the barrel mostly cool before doing the next string.

Thoughts and analysis appreciated

velocities were:
46.0 - 2887, 2882, 2891 (es 9, sd 4.5)
46.4 - 2898, 2898, 2910 (es 12, sd 6.9)
46.7 - 2914, 2911, 2908 (es 6, sd 3.0)
47.0 - 2948, 2943, 2952 (es 9, sd 4.5)
47.4 - 2970, 2949, 2975 (es 26, sd 13/8) -- suspicious of that one 2949 one

 

[Tripwire]

Re: OCW - 308

"pretty windy"....for sure.

 

[killian hennessy]

Re: OCW - 308

quiggyb,

looks good

for the feedback from analysis to be beneficial, if is best to know if you are intending to shoot mid-range or long range?

i shoot long range
so from my perspective, my .2c worth is as follows
the load at 47.0gr looks ok for the following reasons-
speed @ average of 2947fps depending on your latitude should keep you above mach 1.25 for the 1,000 yards
the smallest vertical dispersion looks to be 47.0gr
i would not focus too much on the lateral dispersion, due to the windy conditions.
you could consider repeating the ladder, more focusing around the 47.0gr by loading in 0.2gr increments i.e. 46.6, 46.8, 47.0, 47.2, 47.4

last of all, enjoy

 

[QuiggyB]

Re: OCW - 308

In repeating with finer increments, is that still 3 shot groups looking at vertical placement or more shots per group to get a better idea about consistency of velocities? Also should I keep doing it at 300 yards or can this be done at 100 yards.

I do 1000 yard fclass with a .284 and alternate between fclass and ftr (.308 off a bipod) for 300/600 yards.