Bullet Sorting – Weight vs BTO vs BS

[tbrice23]

I threw on a creedmoor barrel, grabbed a handful of 1x fired Hornady brass picked up from a long range class, loaded up some 147 eld's. A quick velocity ladder revealed a node, I tested that node and wound up with a 8 ES and 3 SD.

So no water weight sorting, no bullet sorting, no case sorting of any kind, no brass prep.

This weekend I did decide to conduct a test. I dry and water tested a batch of random cases. The cases ranged 4 grains of each other. Water weight testing ranged .9. Cases were 2.7% and water was 1.6%. Case weight and internal case volume are not related. Lightest and heaviest cases had **** near identical water weights.

Future test coming:
I took a lot of 5 of exact water weight and lot of 5 of random cases within 1 grain. I trimmed, neck turned, etc. Actual decent brass prep so at least neck tension was close etc. I have always felt bearing surface was more of concern than weight so I am planning to sort the test bullets by BS. The goal is to see if the case volume/weight has much of an impact on fps variance. I have been told by a few bench guys they like to keep it to .5 grains water or less.

Bullet weight. In my experience a rule of thumb is 10 fps per grain of bullet of weight. A 140 and 147 will generally be about 70 fps difference. So a bullet that is within 1 grain total weight is good for a 10 ES generally. For every 10 ES at 1000 yards it is roughly .25 MOA variance.

It'll be interesting to see if all this amounts to anything. My assumption is that'll help with flyers when the worst bullet, worst neck, and worst case volume are matched up.

Keep us updated.

 

[Greyfox]

I threw on a creedmoor barrel, grabbed a handful of 1x fired Hornady brass picked up from a long range class, loaded up some 147 eld's. A quick velocity ladder revealed a node, I tested that node and wound up with a 8 ES and 3 SD.

So no water weight sorting, no bullet sorting, no case sorting of any kind, no brass prep.

This weekend I did decide to conduct a test. I dry and water tested a batch of random cases. The cases ranged 4 grains of each other. Water weight testing ranged .9. Cases were 2.7% and water was 1.6%. Case weight and internal case volume are not related. Lightest and heaviest cases had **** near identical water weights.

Future test coming:
I took a lot of 5 of exact water weight and lot of 5 of random cases within 1 grain. I trimmed, neck turned, etc. Actual decent brass prep so at least neck tension was close etc. I have always felt bearing surface was more of concern than weight so I am planning to sort the test bullets by BS. The goal is to see if the case volume/weight has much of an impact on fps variance. I have been told by a few bench guys they like to keep it to .5 grains water or less.

Bullet weight. In my experience a rule of thumb is 10 fps per grain of bullet of weight. A 140 and 147 will generally be about 70 fps difference. So a bullet that is within 1 grain total weight is good for a 10 ES generally. For every 10 ES at 1000 yards it is roughly .25 MOA variance.

It'll be interesting to see if all this amounts to anything. My assumption is that'll help with flyers when the worst bullet, worst neck, and worst case volume are matched up.

Good info! Be interested in your results!
You hit the nail on the head.....all the anguish in managing the loading process and component selection is geared towards an attempt to eliminate/reduce flyers with a particular barrel/load. After years of testing and experimenting with all the variables with my competition and hunting rifles used for LR precision, my personal formula that seems to get me to a a high confidence with reduced flyers is:
-custom barrel/trued action
-100-200ct of same lot brass(usually Lapua/Norma which is superb brass which does not usually require sorting...or annealing given the chamber dimensions.
-sufficient same lot bullets that are under .002" in BTO and BS, and under +/- .1gr weight, to last the estimated life of the barrel. Same lot Bergers and JLK's are tight! I'll sort SMK's and Hornadys.
-Sufficient same lot match primers, and powder(measured to .1gr) to last the estimated life of the barrel.
-Dyes/settings dedicated to the load.
-it can take 50-200 rounds to develope a load and fully stabilize a new barrel.
-Find the cleaning regimen that maintains consistency. This "can" be a source of flyers...ie carbon ring, copper, etc.
While it's not always possible to always do all the above, the closer, the better.
Flyers can be caused by several factors. I have also found that they can be one of the first signs that the barrel is on its way out.