Sorting bullets

[Bat Rastard]

I shoot custom bullets so thjey're pretty consistent right out of the box, I sort by OAL and run them on Bullet Genie to eliminate any outliers

Have you ever shot a group with the culled outliers? I am curious as to how that would turn out.

 

[quest450]

I have not, use them for foulers, I love testing as much as competing but maybe in this particular case my brain just doesn't care to know the results

 

[ELR LVR]

OAL is a function of the pointing operation and how the meplat is formed. IT MEANS NOTHING. Spend yout time uniforming meplats. At distance that means something.
Ogive to base may/will mean something. When I did testing measuring the differences in BC, influenced by the meplat, I saw no difference in BC numbers of bullets that varied as much as .030" OTB. That's not to say OTB should be ignored but at 200 yds a lot gets lost in the noise.

So are you saying:
Meplat dia. all being uniform--- is more important than
---- trimming the meplat so that OAL is the same?
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I have heard that if meplats are small to begin with such as .22 and 6mm, uniforming doesn't affect them a whole lot
But makes more of a difference when uniforming .30 cal

 

[DaveTooley]

So are you saying:
Meplat dia. all being uniform--- is more important than
---- trimming the meplat so that OAL is the same?
-----------------------------------------------------------------------
I have heard that if meplats are small to begin with such as .22 and 6mm, uniforming doesn't affect them a whole lot
But makes more of a difference when uniforming .30 cal

Very much so. Meplat uniformity means everything when it comes to BC spreads. That's the only reason to trim them. I'm not say large variations in OTB should be ignored but that has very little to do with BC uniformity, which as distance increases and becomes one of pillars of ELR. Within reason OAL after trimming meplats is only important in the pointing operations. It has little affect on BC uniformity. In my testing where I trimmed meplats on one side and installed tips on the other side there was a BC spread of 5-6% between the two. That's not talking into account the BC spread in each of the groups. So the individual bullet extremes were greater than that.
Misshaped meplats induce yaw in the bullet.

 

[ELR LVR]

Very much so. Meplat uniformity means everything when it comes to BC spreads. That's the only reason to trim them. I'm not say large variations in OTB should be ignored but that has very little to do with BC uniformity, which as distance increases and becomes one of pillars of ELR. Within reason OAL after trimming meplats is only important in the pointing operations. It has little affect on BC uniformity. In my testing where I trimmed meplats on one side and installed tips on the other side there was a BC spread of 5-6% between the two. That's not talking into account the BC spread in each of the groups. So the individual bullet extremes were greater than that.
Misshaped meplats induce yaw in the bullet.

Interesting because I thought/read
The longer the air is attached to (a thing) wing/ projectile / missile, etc. the more aerodynamic it is
One reason why we would place a stator (connection) between 2 places with an open area in between them - to keep the air attached between the 2 points to not allow a break in the air flow
It is when there is a break in the air attachment (base) is when there is more drag
The sooner the air breaks away the less aerodynamic the projectile
The longer the air can stay attached, the better....
For instance, an airplane wing is more aerodynamic than a round piece of copper wire the same thickness for this one reason alone.
And a longer bullet having higher BC, seems to stand to reason one of the reasons is because....
the air is attached to it longer (because the bullet is longer)
So-----to me uniforming total length would make sense, since the front is just pushing a mach wave more than anything.
While I understand the pointier/sharper the front the object is, the easier it is to slice through the air,
I would have thought that ...if all projectiles have the same laminar attachment, due to same length,....
that would make BC more uniform than frontal surface area.
-
So I am open to correction here based on your results
I can tell you've done more testing in this area than I have

 

[jackieschmidt]

As I purchase bullets from a high quality custom supplier for my HV 30br I didn’t think sorting was going to be necessary. Decided to do an initial weight sort on the 1K I just received, 118gr .308. All were 118.0gr to 118.3gr with 80% being 118.2/118.3gr. BUT, I pulled 3 that were at 125.4gr!! WTH? Measured the bullet profile dimensions and they match the others.. Lessoned learned, now have to determine if there is any advantage to doing a dimension sort on these also…..

That is strange. I have no idea how that could have occurred, for the simple reason that it would be impossible to seat a core that weighed 7 grains more into a jacket that was set up to receive the lighter core that as 7 grains lighter. At the very least, the jacket would have popped.

Those three obviously made at a different time at 125 grains and some how got mixed in. You are lucky you weighed them. Being on the same jacket, if you were shooting a near max load, and suddenly introduced a bullet that weighed 7 grains more into the equation, you might have hat to beat the bolt open.

 

[Rwfish]

That is strange. I have no idea how that could have occurred, for the simple reason that it would be impossible to seat a core that weighed 7 grains more into a jacket that was set up to receive the lighter core that as 7 grains lighter. At the very least, the jacket would have popped.

Those three obviously made at a different time at 125 grains and some how got mixed in. You are lucky you weighed them. Being on the same jacket, if you were shooting a near max load, and suddenly introduced a bullet that weighed 7 grains more into the equation, you might have hat to beat the bolt open.

Yes, it is puzzling. Checked several times and always the same. No issues with prior lots so it’s a strange one. Haven’t critiqued the dimensions as I just planned to toss to the side and not use….

 

[ToddKS]

I usually only shoot out to 200 yards. For my 6 Dasher, I shoot the Berger 105 hybrids. Would sorting bullets by overall length do me any good? I seat the bullets using the BTO process. I opened a box and sorted them anywhere from 1.244 to 1.259 inches. What makes sense? If sorting by overall length, do you group certain lengths together, and maybe use the outliers for blow off shots or fouling the barrel? Thanks for your time.

If you are going to sort by length, purchase the Accuracy One Bullet Comparator. It is $160 plus shipping. It started sorting with calipers but purchased the Accuracy One tool because working the calipers was hard on the hands. Once I had the tool I resorted what I had previously sorted with the calipers. It was clear that the results from the caliper sort were very inconsistent. The tool can be ordered from bullettipping.com

 

[mikecr]

if all projectiles have the same laminar attachment, due to same length,....
that would make BC more uniform than frontal surface area.

The same length part is a generalization.
Each attribute of the bullet provides individual contributions. Like base diameter/base angle, and ogive radius for example. Meplats are a big contributor.
All independent of OAL.

I suppose it's possible with a brand/lot of jacketed bullets to find only one attribute in variance.
Single attribute sorting could work -only in that case.
Machined solids would remove all need,, if they shoot.

If a crazy person measured every bullet dimension/angle, and calculated BC with these numbers, per bullet, they would likely find that sorting from any single number(other than resultant BC) is a bad idea.
That a bullet reading 5thou shorter OAL for example, falls right on mean BC for the lot.
Meanwhile, another bullet that matches mean OAL for the lot, falls outside mean BC for the lot.
You could then cull out a good bullet and keep a bad bullet.

Until there is an affordable laser scanning comparator, that you can tie to excel, the best answer is to find a mythical Clinch River kind of bullet, buy them in very big lots, and just use them.

 

[Mulligan]

The same length part is a generalization.
Each attribute of the bullet provides individual contributions. Like base diameter/base angle, and ogive radius for example. Meplats are a big contributor.
All independent of OAL.

I suppose it's possible with a brand/lot of jacketed bullets to find only one attribute in variance.
Single attribute sorting could work -only in that case.
Machined solids would remove all need,, if they shoot.

If a crazy person measured every bullet dimension/angle, and calculated BC with these numbers, per bullet, they would likely find that sorting from any single number(other than resultant BC) is a bad idea.
That a bullet reading 5thou shorter OAL for example, falls right on mean BC for the lot.
Meanwhile, another bullet that matches mean OAL for the lot, falls outside mean BC for the lot.
You could then cull out a good bullet and keep a bad bullet.

Until there is an affordable laser scanning comparator, that you can tie to excel, the best answer is to find a mythical Clinch River kind of bullet, buy them in very big lots, and just use them.

How much variation could there possibly be if all the bullets in your lot came off the same die/punch?
I can see slight variations in length due in part to variations in jacket length and variations in lube, but most other attributes are mostly fixed, are they not?
CW

 

[6BRA]

How much variation could there possibly be if all the bullets in your lot came off the same die/punch?
I can see slight variations in length due in part to variations in jacket length and variations in lube, but most other attributes are mostly fixed, are they not?
CW

65 to 68 gr., .004 across 1000 BTO. 80 TO 115...007 TO .010 Across 1000 in BTO. Shorter bullets don't have as much variance. These are customs I am referring to. Only way to prove it is do-it-yourself. OAL varies within those sorted sublots. I don't read alot into OAL sorts. May help to explain a small portion of PPC success. Nose region is problem child of long bullets. Jmo

 

[tom]

I don't ignore oal sorting, and is the one thing even on real bullets.

Tom

 

[6BRA]

I don't ignore oal sorting, and is the one thing even on real bullets.

Tom

Is that the only sort you do? OAL, or is it coupled with other sorts/ trims/ points? Hard to dispute your results.

 

[tom]

Is that the only sort you do? OAL, or is it coupled with other sorts/ trims/ points? Hard to dispute your results.

Situation dependant on testing with trimming and or pointing. If they test better or equal i will shoot a match Saturday one way, Sunday the other until I see a winner.

My bullets, Roy's, or now Kristina's, TomEs, original Spenser etc... yes just lengths.

Store bought....there's not enough Tupperware on earth to hold enough piles lol.

Tom

 

[mikecr]

How much variation could there possibly be if all the bullets in your lot came off the same die/punch?

Probably little. Were your bullets made that way?

I can see slight variations in length due in part to variations in jacket length and variations in lube, but most other attributes are mostly fixed, are they not?

You won't ever know unless you measure (more than just OAL).

People think that doing something, anything, is better than nothing.
But outside of testing, it's usually reckless to act with missing information.