Standard Deviation

[gregrn43]

When y'all are working up loads for a hunt, what is the standard deviation that you look for? I'm working up a load for my 300 win. 180gr scirocco with H1000. With 80grs I have a std dev 10.4. Max velocity is 3102, min velocity 3072. Rifle is a Ruger M77 mark II 24 inch barrel. This SD was with a 5 shot group. The load shot pretty good, but I think I need to tweak my sitting depth a little. I cant extend it very much because it will not fit in my magazine. I shot 4 different loads and this is the best SD that I had.

 

[USMA84DAB]

10 shot group - Std Dev of 7.5 FPS - looking for 2650 FPS, 10 shot average was 2654 FPS. I called it good.

 

[samson7x]

I like it to be <10 but if it groups 0.5" at an SD of 14, I'm rolling with it.

 

[Surgeon1]

Real frankly I always strive for Std Dev less than 5 no matter the caliber, but sometimes it just isn't achievable. Specific to Swift Scirocco, I've used them in several 30 cal rifles and most of the magnum cases. Ditch the H1000 and go to RL17 or to 4350. The H1000 is to slow a powder in the 300WM in my opinion. Swift Scirocco and Std A-frames seam to work best at 2850 to 2950 IMHO.
I use the 200gr A-frames at 2850 on everything from elk, moose, and African plains game thru eland.
Save the H1000 for 300RUM. Also, most rifles in 300WM that I've worked up 180 Scirocco's for like
20-40 thousandth off the lands.
The load you have sounds surprisingly good for H1000 and it is very temp stable but when compressed loads it can do some weird things pressure wise. H4350 is about as temp stable as you can get. Unfortunately, RL17 isn't very temp stable, but in 300WM I've seen some of the best accuracy. I've also had pretty good luck with 4831SC and it meters well and is super stable.

 

[gregrn43]

I have always used reloader 23 in my win mag, but as the last few years I've not been able to get Alliant powder. Not to mention the cost has skyrocketed. I went with H1000 because my nosler reloader book showed it to be their most accurate load with 180gr bullets. I have tried 4 different charge weights with it. I have H4350 I'll give it a try.

 

[Schüler Jumbo]

I strive for single digit Standard Deviation.

 

[Doug3006]

I’ve handloaded for 30 plus years. I’ve been down most every rabbit hole you can name. Especially when I was shooting lots of prairie dogs in the 90’s. Lately, I’ve stopped chronographing at all! I use the reloading manuals recommended loads and rely on the published velocities. If the bullets fall within an inch of point of aim, I call it good. I know how much fun it is to kufutz with loads so I’m not trying to talk anyone into my lazy ways. But on big game, I just haven’t seen the need.

 

[jruby]

I have been reloading since the mid 80"s and I have reloaded pistol and centerfire cartridges. My primary goal is accuracy. I have found that the lower the standard deviation the more accurate I am. Then I worry about velocity last. I am willing to give up velocity to get accuracy. My goal is less than 10 fps Standatd deviation. Rarely have i ever got this with manufactured ammunition. .I have only hunted north America. To me if I can't hit what I am shooting at velocity is not going to help me. I am not a long distance shooter.