Pelletgage diameter - which to record/report

[bambuino]

Hello --

Got a new rifle and my groups at 100 YD need improvement. I have some washed and weighed pellets from last year. Received a .25 cal Pelletgage from AoA last week and sorted out head sizes. Purely anecdotal at present, but at a 100 YD a 6.37 will group center, whereas a 6.38 of same weight will group a 1/2-MIL high and right. After a bit of that I shot from that weight group but did not sort heads and pretty much same groupings, only randomly as drawn from tin. So, well on the way to figuring this out. Sorry, getting long here.

So, as I gauge these head diameters, I have been sorting and recording by the smallest diameter that the head of the pellet will pass through, the "go" diameter, the skirt being hung up. I think I have read elsewhere though that the reported head diameter would be the next smallest diameter, the "no-go" diameter.

What is the accepted convention for reporting pellet head diameter according to a Pelletgage were I too share that info here?

Thank you, Mark

 

[JamesD.]

Once you buy one of these for your .177 , 22 or .25 & decide what head size your barrel likes, buy the Pelletgage R that helps you find them fast.
https://www.ebay.com/itm/194067366469

But I gotta tell you most AG barrels like straight .250

 

[bambuino]

Hey James, that's a pretty nifty gauge.

 

[JamesD.]

It's convenient for in the field but Pelletgage R is better to sit down and do a entire tin or more.

You could also just use a caliper or micrometer to measure & sort pellets by initial head size and their relative group size. People may not know but as little as 0.001-0.005 is going to be the difference between meh and excellent barrel/projectile mating.