Standard deviation

[AZ.noob]

308 Winchester; 168 & 190 grain SMKs over Varget through a Savage 10.
The rifle and loads are capable of solid half-minute accuracy when I do my part.

I hand-measure each charge individually, into weight-sorted Lapua cases. Seating depth doesn't seem to make measurable differences in the chrono numbers. Primers are CCI 200s.

My SDs for 10-shot strings are typically in the 20-30fps range. I'm relatively new to the precision discipline (about a year) so I haven't done much beyond 200 yards, yet. The goal is 1000 yards, as I have access to a high-power range. The desert is really big too

Question is, what can I do to tighten up the SD? Or, is 30fps 'acceptable'?

 

[rduckwor]

It certainly ain't bad.

I am happy with those SD numbers when I can get them.

 

[P7id10t]

308 Winchester; 168 & 190 grain SMKs over Varget through a Savage 10.
The rifle and loads are capable of solid half-minute accuracy when I do my part.

I hand-measure each charge individually, into weight-sorted Lapua cases. Seating depth doesn't seem to make measurable differences in the chrono numbers. Primers are CCI 200s.

My SDs for 10-shot strings are typically in the 20-30fps range. I'm relatively new to the precision discipline (about a year) so I haven't done much beyond 200 yards, yet. The goal is 1000 yards, as I have access to a high-power range. The desert is really big too

Question is, what can I do to tighten up the SD? Or, is 30fps 'acceptable'?

You didn't say much about your chrono and measurement setup, but those numbers are approximately ±1.5% of your MV. Haven't read the operating specs on my chrono but I would expect that to be about the limit of its accuracy.

So if you're shooting a dime or nickle hole at 100 yards, what kind of accuracy are you looking for, and can your Savage deliver it?

 

[armorpl8chikn]

I am not happy above 15 and I have a rifle that will do single digit SD's so I am a bit spoiled. You might try annealing for better more consistent bullet pull. You could also try BR2 primers.
It is a factory rifle Don't expect it to do much better. How does it shoot at 1000yds? Much is made of laboratory results that may or may not mean much at the target. Until you shoot it at distance you really don't know anything about the load. Don't let a piece of electronics have the last word in your shooting...ever.

 

[AZ.noob]

Thanks for the input fellas. Very cool

Aside from bedding the action, it's a bone-stock factory rifle. I do anneal every second or third cycle, and I do them all at once so that I don't have half a batch just-annealed, and the other half with a cycle or two. I'll try to find some BR primers, to see if that helps. And, of course I've gotta stretch it's legs out beyond the 200 yard limit at my local range.

Thanks again guys, much appreciated