Sorting bullets by surface length?

Tod what I don't get is one rifle seems to like the shorter Ogive but my light gun likes the longer. Is that maybe a difference in barrel twist, but they are both 1-10 go figure. Like you and I agree on thats the only part that touches the barrel I was told by someone ,a top shooter that if tip to base are different in lenght when shot over a chronograph your extreme spread will suffer.

Joe Salt
 
Bob Greens comparator provides a relative measure of ogive radius. That's what ogive is(curve of a bullet’s nose), and not any particular datum on the nose.
It takes any TWO measures of a nose to define it's ogive. NOT one.
While ogive radius variance can slightly affect land contact angle, and so contact datum 'distance' w/resp to lands, it is way too small to make any difference to tune. It is however, a significant qualifier for bearing length comparisons, and nose trimming(aka meplat uniforming). This because ogive radius changes all bullet nose datum points.

The 1thou tolerance on nose to base is meaningless without accounting for the reason(s) behind it. BC isn't affected much back there(like it is up front), and I've yet to see measured velocities affected by bearing variances.
If you really care to reduce vertical, then cull by ogive radius and discover a way to uniform meplats. That is, actually make all noses and meplats -the same size.
 
Good luck, Mike. Part of what I was trying to tell them. The other head knocker was no one could seem to figure out how a bullet seater works; that all too many push on the point of the bullet. Any variance in length from the shank to the point -- with such a seater -- winds up affecting jump/jam.

The ogive shape/radius usually isn't the culprit. It is how much of the bullet bleeds up into the knock-out pin hole when the bullet is pointed up. I've trimmed meplats where I seen the "new" meplat size differ, now that they're square. Shows up even better when you re-point.

Wilson seaters are apt to pick the bullet up a little too far forward, unless you go in with a lathe & bore out the inside of the stem to pick up the bullet closer to the shank/ogive point.

As far as this post goes, I gave a report on actual chronograph variation done, with respect to 100 yard velocity differences. None of that seems to counter the *I believe* notion. It's a religion. Trash talk. Science not welcome.

So, I pulled the posts. Think I'll quit the long-range forum.

Edited to try to be clearer. Probably doesn't matter.
 
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Mike i agree mostly with what you said. I measure my bullets for bearing to find that 1 in 300 bullet that is 10 or 20 thous. different. While i have done the measuring i might as well keep them segregated. I then measure the OAL of the bullet so the shape stays close to the same from bullet to bullet. If one bullet is 10 thous. longer it has to be more aerodynamic. Matt
 
The reason I couldn't figure out what you meant Charles is that early on in my reloading I learned the bullet nose or tip should never touch the seater. It's a poor place to push from being easily crush-able and inconsistent in form.
 
charles i call bs on this statement. remember this is a BENCHREST FORUM AND THE LONG RANGE PART OF THAT.
NO ONE WITH THE SKILL TO LOAD AND SHOOT 600/1000 YD USES A SEATER THAT CONTACTS THE BULLET TIP.period.
none zip zero used in BENCHREST.......cause if it did the guy would win nothing, get disgusted and never come bqck. its got to be one of the first things any COMPETENT loader learns.
just one more in a long line of you cannot teach an old dog anything.

mike in co
Charles E said:
Good luck, Mike. Part of what I was trying to tell them. The other head knocker was no one could seem to figure out how a bullet seater works; that all too many push on the point of the bullet. Any variance in length from the shank to the point -- with such a seater -- winds up affecting jump/jam.

.[/I]
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Charles,

Sorry you pulled your posts. Your last post states that you gave a report on actual chrono variation done. All I remember is you stating that we need lots of wire (I was assuming you ment for he chronograph) to make the test. Since I have a short memory I can not quote you. But, I don't remember any report. If there was one, i missed it and would be interested in seeing it.

As far as bullet seaters...... If bullets seaters actualy do push the bullet in from the tip, I will be the first to say that any variation from the tip back to the major caliber will affect seating depth and oal!! I just figured that ALL of my specialty measuring tools measure from the same spot on the bullet. I had been calling that "point" on the bullet the ojive. I guess I don't have the vocabulary to give the proper name of that point where that bullet hits the lands. I had assumed, wrong or not, that since all of the specaltiy tools measure from this spot, and this is where the bullet either is jammed or jumped, that this is also the spot where the bullet seater does it's thing. If I am wrong, I am sorry. Also, If I am wrong, I got a whole of learning to do. Try and figure out how to make my bullet seater to seat the bullet from the same place that my tools measure from.

Question 1) What is the proper name of the exact point where the bullet hits the lands, the point where all of my tools (except, evedently my bullet seater) touch, along with that chunk of BBL my smiths always sends with my new BBLs, the point where the bullet bearing serface radiuses, or curves toward the tip? What do I call that point? If we are going to dicuss it, it should at least have a name!!

Question 2) Which, if any, bullet seaters contact and seat the bullet from the above point? It seems to me that this would have been the logical spot on the bullet in which to have the seater push the bullet into the case, but I guess not.

Question 3) What are the effects of different bearing serface lengths on velosity, PSI, and impact points at long range?

Queation 4) What is the major factor with bullets that have different tip to whatever that point's name is on the bullet measurments on bullet flight.....is it bullet BC, or the affect that the differing measurements have on jump/jam/fps/psi?

Question 4)....Do you guys sort bullets? Why or why not? Also, HOW do you sort? What is your criterea (sp)?
 
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Most of this post is very interesting, even though I'm a "point-blank" kinda guy and "technically challenged" compared to most of you. Some of the terms need clarification in my mind. When I use my comparator tool in my caliper it measures at a point on the ogive of the bullet. Not, however, the same place where the ogive contacts the lands and certainly not the same point the seating die contacts the ogive. How do I correlate all the different measurements?

I have Wilson, Forster, Redding and Hornady "benchrest" or "custom" seating dies, none of which contact the bullet in the same place and none of which touch the bullet as far down on the ogive as my comparator. I believe that my concern is "seating depth" which is not what the OP is referencing in his post about "surface length", so be patient with me.
 
You guys suppose these odd posts from Charles are a test or trick to screw with this newbie here? :)
 
The way I see it there is no simple way to correlate the positions of the different bullet contact points with regard to seater, comparator, and others. It will take some careful measuring and math on each of your tools, and a chart to refer to, to be able to use one against the other. If all of the tools used a similar angle or contour at the contact point then they could be used with each other, then the accuracy of that still would come into question.
 
my seaters contact somewhere on the ogive.
my measuring tools measure somewhere on the ogive.
the net result is that of i move my seater die .005, my measure tool shows a .005 change.....that is all one really needs as far as seating adjustment.
my dies do not touch the tips of my bullets.
now back to our regularly scheduled program: "sorting bullets by bearing length"

the announcer asks tod s.." didn't you win some majot match this year ?, and how were your bullets sorted for that match ?"
 
Yes, I did win the IBS 1K two gun Overall, LG group, and LG overall, 2nd in HG score, and sixth in LG score. ALL of my bullets were sorted by bearing serface length using Bill Shehanes "device".

But, and maybe the rest of this belongs in another post....but, all of the questions I asked in my last post are dead serious!!

Either I am COPLEATLY CLUELESS, or some, or all of the information given on this thread is suspect. Like I said, I don't have the vocabulary to properly voice my questions/concerns.

Then again, I didn't use or have my vocabulary at White Horse WV...didn't know I needed it.

I am not big into pissing maches...I AM big into lerning how to shoot small(er) groups and high(er) scores!!

Thanks,
Tod
 
Can I ask what differences in bearing length you are seeing with that method Tod?
 
I basicly grab 10 bullets, measure them, find the "middle", and set my dial indicator to zero using that bullet, and continue to measure the rest of the bullets. Different lots of bullets vary. I had ONE box of 100 105 VLD's, and only one box, that had nearly a twenty thou spred (+.010 to -010...OK maybe that is 22 thou) I usualy get about a six or seven thou extream spread. I think the box of 500 108 Berger BT's I used at the nats in my dasher ran 5 thou extream spread. I did a box (500) of 30 cal 240 SMK's that was three thou!!

I am only measuring bearing serface....the begining of the radius of both the nose and the BT base. A while ago I tried sorting by weight after I sorted by bearing serface.....I tell you what...I am not that organized to keep all of the batches seperate...I no longer weigh my bullets. This may or may not jump up and bite me on the hiney some day!!!
 
If you don't weigh, then have you tested sorting just by length against sorting just by weight?
 
dk hunt 14 said:
I measure my bullets for bearing to find that 1 in 300 bullet that is 10 or 20 thous. different. I then measure the OAL of the bullet so the shape stays close to the same from bullet to bullet. If one bullet is 10 thous. longer it has to be more aerodynamic. Matt
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This is not really true. If the bullet is longer, because the nose is longer, with higher ogive radius and larger melplat(which makes sense), BC could be lower.

Also on other discussions, there is not an official datum where a bullet nose would contact lands(contact datum). And there would be no way for a tool maker to predict that point without knowing your leade angle and bullet ogive radius and type. ALL available tools provide only a relative datum point, following no standard at all.
There is also no standard w/regard to seater contact dimensions or angles. These are also relative only.

The reason seater plugs don't contact as high on noses as a leade 'contact datum' might be, is because of wedging created by such shallow angles. This wedging would create variances in seating with relatively small variances in neck tension. I'm sure die makers like Wilson choose contact where seating is most consistent with various nose types and reasonable tension. They would have no option but to assume you're seating bullets which are consistant in dimensions.
IMO, there is nothing wrong with Wilson seater plugs, and I would not want them to change.

Oh, and I guess I should declare, I am not a competitive shooter....
 
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sorting bullets

does the davidson conparator from sinclair do the same job as the one from bob green and D and B supply one with calipers and the others with dial guage jus trying to see the difference


thanks in advance
 
They're all 'Bearing Surface' comparators(same function), except for BobGreen's, which is an ogive comaparator.
I tried the caliper attachments for a bit, and could not get repeatable readings with them. I had better luck with the Tubbs/JB comparator stands. Probably because the force is set by the dial indicator instead of my squishing of calipers.
 
dk hunt 14 said:
I measure my bullets for bearing to find that 1 in 300 bullet that is 10 or 20 thous. different. I then measure the OAL of the bullet so the shape stays close to the same from bullet to bullet. If one bullet is 10 thous. longer it has to be more aerodynamic. Matt
Click to expand...
mikecr said:
This is not really true. If the bullet is longer, because the nose is longer, with higher ogive radius and larger melplat(which makes sense), BC could be lower.
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Mike, where do you come up with this stuff? So you're saying that if I grab a box of bullets, I'm gonna find bullets in there that have 2 different Ogives? Different enough to make a longer bullet actually have a larger meplat than a short one? What are you smokin? What you should do is not sort 190's with 210's, or 95's with 105's.

Oh, and I guess I should declare, I am not a competitive shooter....
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This is obvious...
 
I'll provide an example, and then go on to smokin somethin else...
Let's say you have a simple tangent ogive 24cal bullet with the following nose measurements:
------------------------
NL = 0.700"
MD = 0.056"
Ogive Radius = 11.0 cals
0.2420" datum to tip = 0.6489"
------------------------

Another could measure:
NL = .700
MD = .065*
Ogive Radius = 11.5 cals*
0.2420" datum to tip = 0.6482"

Another could measure:
NL = .710*
MD = .051*
Ogive Radius = 11.0 cals
0.2420" datum to tip = 0.6589"

Another could measure:
NL = .710*
MD = .065*
Ogive Radius = 11.8 cals*
0.2420" datum to tip = 0.6575"

Check my math if ya like.
This variance/result applies very closely with secant ogives as well. And there is as many possibles with base-to-bearing measurements(caused by BT end diameter & angle).
With this, it's possible that bullets matching in bearing to base, or bearing to tip, even both, might not actually match, and BC could go up or down depending on which is doing what -with individual drags combined.
 
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