Sorting bullets by surface length?

But Mike,

I've done some pretty serious bullet measur'n in my day, and if there had been a variation in the ogives, It would have showed up like a sore thumb. It did not.

I only ever sorted bullets that came from the same lot. But even still the ogive's of similar bullets of different lot did not vary. I figure if the manufacturer already sorted these and said they are different, I don't need to go check. I never sorted a mix of Berger/Sierra/Nosler's. I stuck with just one brand, one weight, one lot. Now, maybe if you are buying bullets from a manufacturer that uses 100 sets of dies and throws all the bullets into one batch, then this type of sorting is needed. But, early on, I weeded out that sort of bullet maker and only shot bullets made by people with a half a brain or more.

If you are saying that two bullets from the same dies or intended-to-be-even similar dies, could have an ogive variation of 11 to 11.8, then I guess I'm done with this thread too. Come'on now, even you have to admit that's a bit of a stretch.
 
4Mesh said:
I've done some pretty serious bullet measur'n in my day, and if there had been a variation in the ogives, It would have showed up like a sore thumb. It did not.
Click to expand...
Just curious 4Mesh, how do you measure and determine each ogive radius?
 
to Mike,

I would like to know how you measure "ogive radius" ?
I never have come up with a good way, and would sure be interested of other ways.

Happy Shooting
Donovan Moran
 
The device commonly used to measure radii is an optical comparator. You project the image of the bullet on the wall, blown up 100 or more times. Much easier to take measures and do overlays that way. Only problem I see is that sometimes you have to cut a hole in the floor to find center of rad........
 
As to measuring an ogive... I can only recall doing it one time, but I did it right. While I do have an optical comparator, I never used it. But, that's pretty much usless information anyway so.

Now, comparing them, that I've done a boatload of. I really don't give a ___ what the ogive is, as long as they're all the same. For that, I made gages, (quite a few actually). I'm going to make a guess that my gages that said the ogives were the same, were more repeatable and suitable than the ones you used to find them varying by 8 or 9%.

/EDIT
May I also ask, why the hell do people post to a thread to say, "PM Sent"?? The person will see it the next time they log on, and might get an email saying as much. How many times do you think they need told about it? Or is that done for all of us who didn't get the PM, so we know something clandestine is going on?
 
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duh....it only helps with a flat based bullet.....you need a tool for each end when measuring body length. while a gizzy is nice its only good till the first few shots are fired and then the throat moved...after that its good for brass sizing only....or a reference to how far the throat has moved.

mike in co
 
i think the bottom line is he does not have a clue.......which is obvious in many of his posts...he is living in the past.....
his last post kinda confirms that opinion.
mike in co
mikecr said:
Just curious 4Mesh, how do you measure and determine each ogive radius?
Click to expand...
 
4Mesh
I suspect you just received a very short e-mail.

Tod
Keep on doing what you are doing and keep on winning.

Donovan
I made an optical comparator last night.Youi need a lamp with the shade removed.A comparator epoxied to a board and some poster paper.
Set a bullet into the comparator tool shut off the house lights and place the lamp next to the bullet being measured.Hang the poster paper up about 12-18 inches from the bullet and trace the outline out.
Swap bullets and watch to see what if anything is happening.Flip all your bullets over and compare the boattails.

LorenC
Nothing you can do to improve your rifles accuracy will show gains like getting your seating depth set correctly.Using your comparator tool set each bullet to the exact number you are after.A variation of 0.003 will give you unexplained fliers.

Mike in Co
Wilbur is back in charge and you can now place the supermoderators of old on your ignore list.I am hopeful this will pump new life into the various forums and increase participation.
Lynn
 
Sorting bullets by surface lenght

Guys your getting your shorts all in a knots again over nothing . Your probably all right in one way or another, so don't turn this into something else. We all agree things change with different bearing surfaces, so when I get some that are different I go to my dummy round and measure to see how much things have changed. No big deal just a few measurments is all. Just keep it simple!

Joe Salt
 
Lynn,

"Nothing you can do to improve your rifles accuracy will show gains like getting your seating depth set correctly.Using your comparator tool set each bullet to the exact number you are after.A variation of 0.003 will give you unexplained fliers."

I think you are saying that after you seat all your bullets you go back and "comparate" each rounds "cartridge base to bullet ogive length" and re-bump each one if needed to reach the desired and important length? Seems this is the only way to achieve the desired result of uniform "ogive to the barrel's lands" parameter in the long run.
 
Lynn, that is one thing that has been worrying me about loading for long range. In my limited, amateur br shooting so far I've loaded at the bench. Now I hear virtually everyone loads at home for long range. The one thing that was very apparent to me loading at the bench was the amount of difference seating depth made. I fear loading at home will cause more issues than lower my confidence.
 
So after all this one part of my original question here I don't think has been answered. How is the bearing surface length measured? Someone have a picture of the operation in process or a more simplified explanation of what I may have missed?
 
TwentyTwoGuy
I seat all of my bullets 0.015 long and re-seat them the night before the match.I do it EXACTLY as you posted.
The vld type bullets we all seem to shoot have some variation to them and this step will get rid of most of your fliers.

LorenC
With the small cartridges like the 6BR and Dashers the load window is around 0.5 grains wide.With the big magnums it is 2-2.5 grains wide and with the 50 BMG it is 15+ grains wide.
Once you have your powder charge right start playing with your seating depth in 0.005 increments until you see your groups tighten right up.Now go back and re-do your seating depth using a comparator and 0.001 increments.100_0102.jpg

I have attached a picture showing 0.001 increments and what you can expect to see.The groups were shot off of a wobbly bench but most shooters will start sneaking up on there seating depth and before they get there they will quit testing and call the one out of the group a missed condition when in reality they were probaly 0.002 - 0.003 off on the seating depth.
I sort all of my match bullets into 0.001 on the bearing surfaces as factory type bullets will vary by as much as 0.025.
When you sort you shoot all like bullets in each group.By that if you have bearing surface lengths of 0.382 0.383 0.384 0.385 all of the bullets are usable but you would shoot each different length at a different group.If you only want to shoot one length plan on custom bullets or alot of factory type bullets.
Lynn
 
as to the how to measure bearing length....
simple and cheap is using two tools on one caliper one on each jaw, this requires skill with a micrometer....
the second is to use one of the tools suggested that uses a dial indicator and two tools.......the dial indicator is a constant force in the measurement..very repeatable.
the tools are basically nothing more then precision holes in blocks of material.....these were origianally things like stoney point and sinclair bullet seating depth measuring tools.

mike in co
 
Lynn. The small size of the increment is something that hadn't crossed my mind. Before, I was using adjustments on the seater stem as small as 1/8 turn. At the high .3's I was shooting I thought the rest of my ragtag equipment was the next limiting factor. Thanks for mentioning that.
 
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So Mike, if I understand you right, the measurement is just comparing lengths between two points, not actually measuring the actual bearing lengths? Should have known.
 
yes you are measuring the length...but from .3 dia to .3 dia or what ever dia the hole in the tool is. could this have a little of the taper in it yes, but you are measuring every bullet with the same tools. its all reference data.
i just measured the hole on my stoney point 30 cal tool...it is 0.296......the body on a nosler 168 is 0.307....
 
100_0327.jpg
LorenC
Here is a picture for You.The caliper runs $12 at Harbor Freight and the two comparators are available from Sinclair who advertises here as well as Bruno Shooters Supply.They are cheap and work well enough.Bill Shehane sells a very fancy tool with a dial indicator and a piece of granite that does this as well as many other measurements.
For a new shooter you don't need any of this stuff yet in my opinion.Go to some matches shoot some groups and see how you do compared to the other guys on your relays.Loading at home is also easy and relaxing compared to loading at the range but guiys like Cheechako(Ray Meketa) still load at the range and he is always relaxed.
Lynn
 
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