- No4 308W 081022_3.JPG (49.59 KiB) Viewed 489 times
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No4 Mk2 308W
Lapua Brass, case volume 56g H2O
Hornady 150g Interlock SP # 3031
CCI #200 LRP
42g AR2208
COAL 2.800"
According to the GRT tool, this combination will produce max pressure of 40071 psi with muzzle velocity of 2610 ft/s
I had to resight the rifle which required replacing front sight blade from 0.045 to 0.075 and a couple of small windage adjustments
1 x 5 shot Chrono results
Avg 2596.8 ft/s
SD 14.1 ft/s
ES 35.0 ft/s
Min 2586.0 ft/s
Max 2621.0 ft/s
1 x 5 shot group (different set to what was chrono'd), group size of 1-7/8" shot at 100M using battle sights off bench with front rest/rear bag with light breeze R-L
I am comfortable shooting this load in my No.4 and will stick with it for a bit and get in some practice then stretch it out to 200 to see how it goes. According to GRT im leaving some powder behind however with my eyes if I can keep it consistent at 2MOA or under at 100 using irons then its prob as good as I am going to get and don't see any point in tweaking an further looking for a more optimal load as I dont want to go under 42G and everything to the right of 42 just increases pressure which I am wanting to keep around 40kpsi. I dont usually use loading software however GRT was free and I was curious to see what it came up with. The velocity was bang on which gives me some confidence in it however as I have no way of measuring pressure I have no way of knowing how accurate the tool is in regards to this but if I do a rough backwards calc using the ADI data for a 42g load compared to their recommended min of 44g then I think it is going to be close. Only time will tell I guess
And the obligatory disclaimer: I am just reporting my results from today using my loads in my rifle and in no way are making any recommendation as to what others should load and shoot in their rifle
