Bullet Sorting – Weight vs BTO vs BS

[Barrelnut]

Couple threads have had bullet sorting pop up recently. I had some ELD-X that I wanted to sort to see how consistent they were. So, decided to compare the 143 ELD-X to some old 140 Amaxs, I have.

In the results below. I weight sorted the 143 ELD-X into .2 Gr groups and sorted those groups by Base To Ojive (BTO) groups of .001

I then weight sorted the 140 Amaxes into .1 Gr. Groups and sorted those groups by Bearing Surface (BS) groups of .001

Things learned:
1) Discovered that BTO and BS correlate to the bullets weight! This means that bullets only need to be sorted by one method or the other and the results will be about the same. Not exact, but very close.
2) BS sorting is easier than BTO sorting. BS sorting with a pair of Hornady comparators on a caliper is much easier and more accurate than BS sorting using only one comparator.
BTO and BS also correlate to each other.
3) ELD-X tolerances are held no where close to Amax tolerances! I assume this is true with ELD-X vs ELD-M too.
4) Last, if all of this gives you a headache, Just shoot Bergers cause their tolerances are way better than Hornady's.

Numbers and how I finally grouped them for my use are below:

143 ELD-X Count = 100

Weight 143.1 to 143.2 = Count 42
BTO .787 = 27
BTO .788 = 12
BTO .789 = 3

Weight 143.3 to 143.4 = Count 35
BTO .787 = 6
BTO .788 = 23
BTO .789 = 5
BTO .790 = 1

Weight 143.5 to 143.6 = Count 20
BTO .788 = 7
BTO .789 = 10
BTO .790 = 3

Weight 143.7 to 143.8 = Count 3
BTO .790 = 2
BTO .791 = 1

My Grouping by Weight:
143.1 to 143.4 = 77
143.5 to 143.8 = 23

My Grouping by BTO:
BTO .787 to .788 = 75
BTO .789 to .791 = 25

AMax 140 Count = 75

Weight 139.8 Count = 5
BS .648 = 4
BS .649 = 1

Weight 139.9 = 16
BS .647 = 1
BS .648 = 12
BS .649 = 3

Weight 140.0 = 47
BS .647 = 8
BS .648 = 26
BS .649 = 12
BS .650 = 1

Weight 140.1 = 7
BS .649 = 3
BS .650 = 3
BS .651 = 1

My Grouping by Weight:
139.9 to 140.0 = 63
137.8 and 140.1 = 12

My Grouping by BS:
.148 to .149 = 62
.147 And .150 and .151 = 13

 

[tbrice23]

Excellent work!
Man, .014" ES for BS for the ELDX... that is really not acceptable.

 

[tbrice23]

The Amax BS ES was only .004.

 

[cohunt]

By the title I thought you were talking about a different BS.

So since you correlated weight and bs and bto, now you need to shoot them with exact same loads to see if mv has a correlation.... then I guess you need to shoot them prone to see if they speed up too.

Check the hammer hunters, I bet the es is tight

 

[wildcat455]

Good job, barrelnut!

I appreciate you doing what I never had the patience for.
Good on you man!

My OCD only runs as deep as a weight sort.

I believe that .004" BTO ES is why I was always tweaking my micrometer seating die to get consistent jump.

I believe that .014" ES on BS for the ELDX is why I was originally experiencing so much velocity variance. Once I started weight sorting, I found I was adjusting the die less, and my velocity ES and SD dropped to single to low double digits depending on the sample size. (Never over 10 rounds, and usually 5).

I originally thought it was a bullet weight issue, because weight sorting improved my results. I then later determined after a whole lot more research and opinions of others it must be a variance of shape that is related to weight, but never had the desire or will to dive that deep.
Besides, weight sorting was getting me to where I wanted to be with them. I just decided to continue to weight sort, as it was working somehow... and resolved to just let the magic happen...
LOL!
Only have about 100 ELDX left, I switched to Bergers primarily, and ELDM for my Hornady selection. The ELDM Seems a little more consistent than ELDX in 30 caliber, but not so much in 6.5.

 

[Barrelnut]

I believe that .004" BTO ES is why I was always tweaking my micrometer seating die to get consistent jump.

Exactly. I have experienced this too.
And in general, I think just weight sorting yields close to the same results as measuring bearing surface.

 

[Barrelnut]

By the title I thought you were talking about a different BS.

So since you correlated weight and bs and bto, now you need to shoot them with exact same loads to see if mv has a correlation.... then I guess you need to shoot them prone to see if they speed up too.

Check the hammer hunters, I bet the es is tight

I hear ya. I've got some twice fired and fresh annealed Lapua brass to try them in. And I guess now the standard should be to state your firing position when you tested them...

 

[wildcat455]

All I know is it made them a little more consistent.

It was all over for me when I started loading Berger's.



My 264 still loves those 147's and I have a 300 win mag that likes 208's...
(It's not throated very long)

 

[Barrelnut]

Check the hammer hunters, I bet the es is tight

Yep, the day I can get em at Walmart, I'll be all over em. They do solve a lot of problems though.

 

[shaughn]

I weighed measured, used a family friends hand made gauges and equipment, checked for out of round, spun them infront of a strobe camera..he had even built himself a paper chronograph and still used it up until his passing, even if the Oehlers were easier... used a template, normally designed for determining BC, but with a little hard work could do a whole lot more....and as far as I found..sorting by just weight netted me near the same result as all that time consuming indepth measurement...

I wasn't shooting for money, where a .000000002 measurement meant the difference between first and fourth...

It does mean buying a minimum 2500 tips at a time, though I like 5K better then sort them all by exact weight, no range like 180.2-180.4...then every time a loaded lot was shot up using the heaviest bullets first...I could grab the next lightest and usually didn't have to do much adjusting if any...but my number of non shooter induced fliers was reduced by a considerable amount.

Was kind of surprised when a talking to LR shooters how few actually sorted their bullets or weighed casings.

 

[Greyfox]

While I will always check(and adjust my load if necessary) OL, BTO, BS, and weight with a lot change with the same barrel, my sorting days pretty much ended when I began using Berger's and JLK's. As an aside, I just received a long backordered delivery of Berger 140 HVLD's. Being curious if the plant move could have effected production quality, I ran measurements. The variations on BTO and BS were amazingly tight, all within .001" !!! I stopped measuring after about 50 bullets. For those that may have noticed, there was a BC change for these bullets a while back: G7 .313 to G7 .307. While this change is not much, I might speculate that this is because the .307 BC bullets in this new lot, compared to my older BC .313 samples, are as much as .030" shorter in OL, and, the bearing surface, .010"-.020" shorter. BTO is within .010"(generally the case with Bergers when testing lot to lot). As usual, bullet weights are most all at 140gr with an occasional +/- .1gr.
Actual testing at 200 yards of this new lot produces comparable accuracy, velocity, and ES to prior lots in the same barrel/load. I still need to check the BC/POI with some 1000 yard testing.

 

[wildcat455]

Yep.

When I shoot Bergers, I don't sort.
It is liberating.
LOL!

Still shoot ELDM, so I sort those.
I guess I'm having a tough time giving up my 1/4 MOA 264 and 300 win mag loads.

 

[wildcat455]

Yep, the day I can get em at Walmart, I'll be all over em. They do solve a lot of problems though.

Except the wallet problem...
Hahaha!

 

[BrentM]

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.