Standard deviation.

[nf1e]

As of late, I have been loading .223 ammunition for precision shooting. Never paid any particular attention to SD. Well, over the last couple of weeks I have been doing a bit of checking on the results of differing variables. Powder is loaded to within .02 gn which is the size of a kernal. Bullets used are Berger 73 gn bt target and have not been sorted by weight. Primers are BR-4s and I have been told that other primers should lower the SD even more. I did not notice any measurable difference in point of impact at 100 yds. Each group tested was 50 rnds, or 1 of my range boxes. Thought some might be interested in those variables.

New Starline .223 50 cases sized and loaded with 23.5 gn of Varget. SD 20+
" " " 50 cases sized, and weight sorted to 1 gn with 23.5 gn Varget. SD 12+
" " " 50 cases sized, weight sorted to 1 gn with flash hole de-burred loaded with 23.5 gn of Varget SD 6.5+


Whatta Hobby!

[JohnMOhio]

Every little bit helps in getting the best results and close to the same results.

[Major Tom]

Years ago I gave up reloading for the best/smallest group @ 100 yards. Now, I am happy to get 'head' shots @ 100 yards with rifle and handgun.