Level of precision

[Dgd6mm]

3 weeks ago I watched a man shoot 2 - 5 shot groups at 600 over a Lab Radar.
Both groups were under 1 inch. The bigger was 0.9 something. This was a 6br. I have no idea what his numbers were or are. All I said that whatever he was doing to make it shoot, it was working. So my question is, what do your numbers need to be to make this happen?

 

[dgeesaman]

I don’t think meticulous loading practices alone will cut es under ten.

There are many other factors involved and not all loads will have low es. Searching for a low es load is not the same thing as doing certain things with precision in the bench.

 

[D-4297]

I think it becomes a combination of so many issues , to even include Barrel harmonics . The so-called "tuning fork" effect . Just a few years ago , a very highly rated shooter won a National Championship in F-Class with a SD of nearly 30 , but his loads were also very consistent . I recently had to change powders , and re-develop my load . After doing the Math for a starting point , the result on Target was very promising , with exceptional grouping at 600 , but the "Desired" velocity was slightly lower than I was after . The SD was 7.4 on fifty rounds . Tolerable . I "bumped" the load by two tenths and got to the desired velocity I was seeking , and the SD DROPPED to 6,2 on the next fifty rounds . I shot this load in a Match last week-end , and won the Match by One point , against some very good shooters . All other Brass prep stayed the same as usual . Matching the powder , to the bullet , to the case prep , to the velocity node , to the harmonics to the primer , to the ......on and on . Isn't that why we do this ?

 

[Jeff Porter]

I shot two strings in competition on e-target two weeks ago that showed one ten shot string with SD of 9.6 and a 20 shot string with SD of 9.0 with a .223. My other strings that day were 12-15 SD. All of this at target not muzzle.
This was done with 4x fired brass, processed un bulk by MS processing. Trimmed and chamfered on a Giraud tri-way trimmer. 205mar primers using a RCBS hand primer, H4895 from a Chargemaster and sierra Match king 77 seconds. I did sort the SMK by base to ogive since they were seconds. No real meticulous prep.

 

[Jeff Porter]