Bullet sorting - base to ogive vs. bearing surface

[memilanuk]

So... for those of you who go this far down the rabbit hole

which approach do you use and why?



As for me... I've got a Tubb BSC stand, with various pieces from Hoover (Accuracy One). As a result, I sort (when I sort) by bearing surface. Seems logical enough, as thats the part of the bullet thats actually in contact with the barrel. I've heard there are others out there (e.g. Bob Green) that may measure at a different point... not sure how much difference it makes in actual practice.

 

[memilanuk]

Re: Bullet sorting - base to ogive vs. bearing surface

BTT... I know I'm not the only one here who has this gear.

 

[DocB]

Re: Bullet sorting - base to ogive vs. bearing surface

Well,

I don't have bearing surface measuring tool, but when I borrowed a buddy's bullet comparator to use in combination with mine and measured bearing surface on bullets I'd sorted by ogive length, the bearing surface was the same, +/- 0.001". I checked 100 each of .243s, .223. and different types of .308s. After that, I've only measured by ogive length, since the amount of jump seems to be more important than bearing surface.

HTH,
DocB

 

[Tomekeuro85]

Re: Bullet sorting - base to ogive vs. bearing surface

Tell me this:

Whats the difference between ogive and bearing surface. Sorry to hijack the thread.. But I'm thinking of machining myself a pair of gauges for .223 that will be say .221 in diameter, so that it will measure just about the point at which the "flat" spot on the bullet ends before it arcs and starts going into a point.

Thats the bearing surface correct?

And ogive? is there a specific distance that the ogive is located at or is it just the whole curve?

 

[Leaddog]

Re: Bullet sorting - base to ogive vs. bearing surface

Base to ogive, then point and trim, and then sort by weight.

Of course, this is getting way too anal. We aren't shooting benchrest here, are we? A .308 is what it is. Wind reading and recoil management far exceeds the benefits of sorting.

 

[memilanuk]

Re: Bullet sorting - base to ogive vs. bearing surface

Tomekeuro85

While I think technically the ogive is the area from the main body diameter to the tip, functionally most people that I know use the term 'ogive' to refer the point where the body diameter transitions to the curve of the nose. Sometimes there is a bit of confusion as the 'ogive' diameter in that sense is markedly different from the 'ogive' diameter where the typical bullet seater makes contact. Bearing surface is the distance from where the body gives way to the ogive at the front of the bullet to where the body transitions to the boat tail at the rear - i.e. the portion that is actually in contact with the rifling. Think I got most of that reasonably correct

Doc,

Maybe you can explain to me the logic behind the base-to-ogive measurement? Bearing surface is the portion that actually contacts the rifling, whereas base-to-ogive includes the boat tail... which to my understanding doesn't contact the rifling, nor the seater, nor much of anything else that matters... what am I missing here?


I'm kind of curious as to the logic behind the various methods - the Tubb/Buhay/Hoover tool measures the bearing surface, others (including the new Sinclair tool) measure only the base-to-ogive distance, and yet another that I'm aware of (Bob Green) measures closer to the portion of the ogive where the seater touches the bullet. I figure there has to be some rhyme or reason to the different methods... just trying to figure out what/why/how...

 

[EWP]

Re: Bullet sorting - base to ogive vs. bearing surface

The Sinclair bullet comparators actually measures the baring surface as well(well base to front of bearing surface because BT is included), not to the ogive length, but you can use one size small and they work very well for ogive measurements.

Quote from Sinclair
<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">Our design allows you to quickly and accurately measure the bearing surface of the bullet. </div></div>

 

[memilanuk]

Re: Bullet sorting - base to ogive vs. bearing surface

Not sure which widget you're looking at (they have many

). I was referring to this:

Sinclair Bullet sorting stand:

Directly from their product description:
<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">...allows you to quickly and accurately sort bullets by base to ogive length.</div></div>

It looks like a slightly lighter and cheaper version of what I have: the post on the Tubb/Hoover model is much bigger, and there is another component that attaches to the dial-indicator tip to go over the bullet boat-tail - and thus measure the bearing surface, not just the base to ogive distance.

 

[EWP]

Re: Bullet sorting - base to ogive vs. bearing surface

I was talking about are the comparator inserts that fit the Hornady comparator body, they contact the bearing surface at the exact point where the ogive starts. The one you posted seems to go off the ogive since the say you can also use the hex nuts that for sure measure from the ogive.

 

[sniperaviator]

Re: Bullet sorting - base to ogive vs. bearing surface

Only way to tell would be to shoot a batch that has been sorted one way and compare that to a batch sorted another way and compare those to a batch not sorted at all. And you are going to need enough samples to make the results signifigant.

 

[James in Wyoming]

Re: Bullet sorting - base to ogive vs. bearing surface

I also have the Tubb stand and use various inserts I got from Bill Shehane, don't recall who made them. Those allow me to measure base to ogive and, if I spin the bullet, also the concentricity. I used it a lot with early batches of 6mm DTACs which really benefited from that kind of sorting, and I will admit the best match performances I have had, both tactical and F-class, have been with bullets sorted using this tool. But I don't use it much anymore, as I find the time spent pointing bullets that are excellent in uniformity to start with (for me, Lapua and some Bergers) pays bigger dividends than sorting by ogive lenth, and I'm only willing to spend so much time producing match ammo as I shoot quite a bit of half a dozen or so different calibers. So, I suppose I would say it is worthwhile
For some applications, like national level F class, but I'm basically not willing to do it on a regular basis. (probably why I'll never make Master!)
Best,
James

 

[RBros]

Re: Bullet sorting - base to ogive vs. bearing surface

Come on Monty, you mean I can't just dump in some powder and seat the bullet

 

[Jedi]

Re: Bullet sorting - base to ogive vs. bearing surface

Sure there are small variances in bullets/cases etc

but i have never seen any hard data that it improved anything, thou many did all work n saw zero diff on target.

hey if ya buy into it n have the time n patience go for it, not for me thou.

 

[DocB]

Re: Bullet sorting - base to ogive vs. bearing surface

Monte,

O.K, I don't know what or how folks define various terms, nor does it particularly matter; since your tools will limit/define how you use this information. Here are your options:

Measure at both ends at where you think the bullet engages the lands. This can vary from rifle to rifle.

Measure at both ends at where you think the bullet engages the bore. This can also vary from rifle to rifle.

Measure base of bullet to either to either of the above dimensions, adding two more measurement variables, not to mention the rifle to rifle variables.

It's a deep rabbit hole....

What I found from my measurements using the Hornady bullet comparator and from shooting the bullet was the bearing length didn't make any noticeable difference when sorting, but ogive length did. Bearing lengths were usually +/- 0.002, but an ogive length variance of more than +/- 0.0025" did. My guess is the pressure forming the base of a bullet is fairly consistent, but the pressure forming the ogive can vary, leading to the ogive variations.

HTH,
DocB

 

[memilanuk]

Re: Bullet sorting - base to ogive vs. bearing surface

7mmAM... go right on ahead with that... I'd prefer that you do, actually

I know some folks, as you do, who seem to be able to load nearly 'match grade' ammo going full tilt on a XL650 (or is it a Super 1050 these days?), using unsorted bulk components. Sadly, that doesn't seem to work for me - trust me, I wish it did. It always seems like when I slack off a little on my LR ammo, either I get taken to the cleaners by someone who didn't, or I miss an opportunity where the conditions just lay down and the barn door is open to just stack the rounds in the X-ring. Hence my interest in always making my ammo just a little bit better... though there are limits (mostly available time) to that, too.

sniperaviator... yep, thats partly why I asked here; to see if anyone else had data to contribute, so I don't have to fire *all* the rounds

Not technically 'correct', but still of some value.

DocB... when you refer to:

<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">
...the bearing length didn't make any noticeable difference when sorting, but ogive length did. Bearing lengths were usually +/- 0.002, but an ogive length variance of more than +/- 0.0025" did.</div></div>

Are you referring to base-to-ogive (base of the bullet to where the comparator touches the nose on the curvature) or something else? Just making sure we're all on the same sheet (more or less), as some peoples 'definition' appears to imply something else (from ogive contact ring *forward*, though I'm not sure how they'd measure it). Have you noticed any significant difference between results measuring the same 'dimension' with one tool vs. another one, that perhaps hits a different spot on the ogive?

My experience with BSL has been that the vast majority are boringly consistent (a good thing, IMO), but I haven't had an opportunity to fire the few 'outliers' back to back with the 'good' ones; for me they usually get relegated to 'sighters' and by the nature of such, their performance is not something I'd base any serious assumptions on. I suppose I probably better set some aside til I get enough, but it may be a while before I have enough...

 

[Greg Langelius *]

Re: Bullet sorting - base to ogive vs. bearing surface

One of the reasons I stopped getting really anal about reloading techniques is because I actually did some blind tests. The results were really confusing. Sometimes they had randomly unrelated outcomes and sometimes they even went counterintuitive. Only on rare occasions did they follow my intuition.

The conclusions I drew were that for non-BR accuracy requirements, it didn't matter whether I did or didn't do a particular back flip.

I divided BR from non-BR on the basis of chamber spec. If it was a SAAMI chamber, it was non-BR.

I only have SAAMI chambers. It makes life easier, and eases my conscience to know that for most tricks, it doesn't matter.

I have further concluded that for bullets, the major suppliers' QC limits are very effective. Getting overly preferential does not appear to make any significant accuracy difference. If you can make one happen, you're a better man than I am, Gunga Din...

I ream flash holes, weigh charges, and do my short-sizing weirdness mojo to manage neck tension. Dassall.

I honestly believe that counter-intuitively, once one gets beyond 300yd, the environmental conditions outweigh handloading tricks. Yes, one need to make consistent ammo, but I believe the things I do make enough difference to be of value, and going beyond them simply doesn't pay off at anything but 'normal' BR comp distances.

Greg

 

[SScott]

Re: Bullet sorting - base to ogive vs. bearing surface

I just picked up some 175's that were in a bulk pack from another hide member, and the first thing I did was sort them. There was quite a bit of spread, but by grouping them I can ensure that I have the same consistancies from box to box of ammo that I load.
For example, I am currently loaing the 175 SMK into RP brass that has full prep(although not sorted by weight) with Tula large rifle primers over 45gr Varget and am getting consistant ES of less than 20 fps and SD's less than 10 fps, with a speed of 2715-2720fps depending on the locations/elevation I am shooting at. Does it make a big difference down range? I think it does, by keeping my SD's so low I have more confidence in making a correction at 900 yards, it helps to calm that little doubt in the back of your mind. LOL
SScott

 

[RBros]

Re: Bullet sorting - base to ogive vs. bearing surface

No loading on a dillon for me Monte...well, except pistol stuff. Each charge is hand weighed on the chargemaster exactly the same, I do weight sort bullets, but I didn't find sorting on bearing surface to give that much more accuracy vs the time it takes to do it. As you are aware of the results of our loading, shooting and rifles

. I am the tinkerer of the two, Jesse would love to just put in powder and seat a bullet, but I am a little more picky.

 

[memilanuk]

Re: Bullet sorting - base to ogive vs. bearing surface

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: 7mmAM</div><div class="ubbcode-body">No loading on a dillon for me...</div></div>

I was referring more to JtP, the anti-Christ of precision reloading

***

<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">...but I didn't find sorting on bearing surface to give that much more accuracy vs the time it takes to do it.</div></div>

I will fully admit its getting into the realm of picking the fly poop out o' the pepper...

Shooting ranges like Rattlesnake (or even sometimes @ NCWGC) there are lots more points dropped to just about anything else; conversely when I'm paying match fees, gas, room & board, etc. to shoot in larger matches it seems it would behoove me not to try and make my groups a little shorter and the target a little wider - at least its something I can do away from the range, so its not really detracting from my trigger time.

I was kind of hoping Tom Sarver would hop on here... I don't have a Juenke machine like he does (haven't ran out of other things I need more) but mebbe he'd have something to share?

Monte


*** Disclaimer: I do, on occasion, load 'match' ammo on my 550 - just not full progressive

 

[DocB]

Re: Bullet sorting - base to ogive vs. bearing surface

Monte,

Ogive length from base to contact point on the Hornady tool. The diameter of the hole on the collets I measured was 0.003" under nominal bore size, for everything from .22 to .338. I don't have any other tools to measure this dimension, so I cannot help you there.

Sierra's and on occasion Hornady's are particularly nasty about having large ogive variances within a box or lot to lot. 0.020" is not uncommon, and I've found 0.070" on some bullets. I think I culled 5 bullets out of 1k when I sorted the last box of Lapua 120gr. 6.5 bullets.

I use the ogive length since I think it can change the case volume as well as effect from the jump to the lands. Tends to remove more vertical than bearing surface. It's also simple, fast, and repeatable. I can sort 500 in less than two-three hours.

I use my 550B to load match ammo all the time. Just weigh each charge and hand prime the cases. It's nice to have all the 30-06/.308 base seaters in one tool head. Same with the neck sizers. Saves a ton of time doing change overs.

SA,

BTDT.

HTH,
DocB