Just wondered. Does anyone have a system worked out to keep standard deviation at or below five feet per second in say 308/30.06 etc in say a 10 round string?
I would be very interested in learning your technique.

Since SD is calculated based on measured velocities there is really no "system" which could apply, except for using extreme care in loading to attain best consistency.

Of course, if SD is all you want to brag on, you can always delete individual shots as they are recorded if they fall too far from the previously determined average velocity. The number won't mean anything, but it will look good on paper.

Just remember, SD really doesn't mean anything anyway. If you get good groups with an SD of 20, and lousy groups with an SD of 5, I'll take the twenty everytime!

Greg Mushial has taught me a lot about chronograph technique. It has a lot to do with uniform results. His convective ignition technique works well for light loads and he expects no more than teens for extreme spreads.
Once you have your load technique down ensure that your chronograph is set to the same distance from your rest every time and use a positive stop that ensures your muzzel is the same distance from the stop screen for every shot. This will reduce your extreme spreads and your standard deviation significantly. You can demonstrate this using the same carefully loaded ammunition and trying the stop and just trying to place the rifle on the rest the same everytime. The difference across the screens will surprise you.

Have monitored the SD with various loads and cartridges, always striving to attain the least and the best groups.

Found this to be a parameter of powder types, mostly. Some give better SD results than others. My finding is that powders must be matched with bullet types, primers and seating depth. Heavy bullets, slower powders - light bullets, faster powders. Used to jockey primers around, but anymore have settled on CCI Benchrest or Federal Gold Metal Match for just about all cartridges, even those using IMR or H4831. Anything slower might get a mag primer if felt necessary.

Just my 2 bits.

Since SD is calculated based on measured velocities there is really no "system" which could apply, except for using extreme care in loading to attain best consistency.

Of course, if SD is all you want to brag on, you can always delete individual shots as they are recorded if they fall too far from the previously determined average velocity. The number won't mean anything, but it will look good on paper.

Just remember, SD really doesn't mean anything anyway. If you get good groups with an SD of 20, and lousy groups with an SD of 5, I'll take the twenty everytime!

Is it pretty common to find loads that are the most consistent velocity-wise not to be the most consistent for shooting groups?

When loading for my 308 Win, I found that one load would give me a standard deviation of 7.26 for 7 shots, but the 3 shot group for this load was about 1.5 MOA, while the load I settled on gave me a SD of 12.18 and shoots sub-MOA (.5 - .7). This is using 168 gr. Ballistic Silvertips, Varget, CCI 200 Primers and new RP brass full-length sized and uniformed.

Just wondering if it was normal to find this kind or thing or maybe I screwed up somewhere?