Does runout matter?

[Viperdoc]

Well, I did notice that with everything mentioned, including turning necks so total runout was less than 0.001 in the necks, in the finished cartridges, runout measured at around the ogive frequently was in the 0.002-0.004 range, occasionally more. The majority of finished shells were in this range, with some, but not many, less.

In the original post, I reported that SD of a ten shot group increased proportionally with increasing runout, so at least in my AR, runout did make a difference in MV. With the lowest runout, less than 0.002 ( only around 1/4 to 1/3 of all of my finished cartridges), the SD was still around 18-19. Good, but not great.

Accuracy out of my AR still ranges around 1", sometimes better and sometimes worse.

What else is there to try? Perhaps it wasn't runout, but I'm running out of ideas.

 

[JERRYHM]

Viperdoc,

Something to try, vary neck tension .002, .004, and .006 and see what happens. The 223 is the hardest round that I have ever tried to tune. They are very sensitive to neck tension (usually more neck tension will reduce the ES) and powders Varget works well with the heaver bullets but might be on the slow side for bullets under 75 grains.

 

[Viperdoc]

Thanks to all for the great tips- wish I had more reloading and range time,sometimes work really gets in the way!

With the Varget loads, I also seemed to notice that with higher neck tensions, the MV average was also higher, but need to check the data again. Just got some Redding type S dies, with the .246 bushing I am getting an OD of around .247 with the spring back. Loaded rounds with the Sierra 69's are finishing at around .250, so neck tension is 0.003.

Will try the .245 and .248 bushings- should give a range of NT from 0.002-0.004. Also will probably go to a faster powder, as suggested elsewhere.