Sorting Bullets For Long Range

R

rcw3

Guest
Just curious what methods people use to sort bullets to eliminate shots outside the group. I had a match last Saturday and used bullets "out of the box" and had a couple loose shots and I am thinking a little bullet sorting may be in order to keep things tighter.

Sorting bullets by weight?

Sorting by base to ogive?

Anything else?

Robert Whitley
 
Sorting bullets

RCW -

Boy.. I have a hard time believing you need spurious input from an inconsistent shooter like me.

I have gone to sorting ( 6mm ) bullets by weight; and have since cut-down on the random fliers a bit. I also think, I need to start mic'ing necks.

What convinced me to weigh was that in my first box of Berger 88s,
I had 7 different bullet weights within the first 10 bullets wieghed.
Overall in the box, I had a max lowest wt-to-highest wt of .7gr.
( Digi scale )

After trying out zillions of various 6mm bullets ( both target and non-target ); I was amazed to find that the most accurate bullet for 100rd groups turned out to be the Sierra 85 HPBT ! When I weighed the first box og the Sierra 85
BTHPs, I only found 4 seperate bullet weights within the first 10 bullets weighed ( Digi scale ).

I took the next step, and weight-sorted all other 6mm bullets I tried out.
The ( what I call high ) weight variance of the Berger 88s continued to be seen over the 3 boxes of them I sorted. The 3 boxes of Sierra 85s I sorted
again... all showed a tighter (smaller ) weight span overall.
The Berger 105 VLDS were somewhat more consistent in weight than the 88s.

I like to shoot 100, 300, and 500yd groundhog and egg shoots.
I believe the weight sort helps for all those ranges. I myself have yet to try my hand at very much 1,000yd work. MIL commitments put a damper on that, for a while. Some day soon, I hope.

I have also tried the ogive sort deal. Non-highpower shooters might find time to screen their bullets utilizing BOTH methods. But, like I've read, the rudimentary weight-sort will probably also cull-out those bullets that would read " off " w/ the ogive measurement method as well.

As an aside, I sometimes wonder about the meplat trim business.
I understand the why of it, but still sometime wonder why a capped bullet
( such as an "A"-Max ) can' t do just as well for a shooter.
No meplat trim... no bullet re-pointing.

With Meplat trim, it's sorta' like " don't ask... don't tell ".
If one were to look at some Sierra MKs with a jaundiced eye, or with any magnification help at all; it would scare you to death. Ug-ly !!

Best regards,
357Mag
 
Robert

I tried but later abandoned the approach of both weighing and base to ogive sorting my long range bullets (600 and 1,000 F-Class). I have continued to sort by length, and it seems to provide the same results as the above discribed weight and length sorting process.

I also point the meplats, but that is beyond the scope of your question.

JeffVN
 
rcw3 said:
Just curious what methods people use to sort bullets to eliminate shots outside the group. I had a match last Saturday and used bullets "out of the box" and had a couple loose shots and I am thinking a little bullet sorting may be in order to keep things tighter.

Sorting bullets by weight?

Sorting by base to ogive?

Anything else?

Robert Whitley
Click to expand...
Robert,
I rarely sort bullets but when I do I sort base to ogive. I made a tool for doing it, if I get around it with a camera I'll take a picture. After that sorting by weight has been a waste of time.
It may or may not matter but I shoot A-max bullets no meplant issues with them.:)

James
 
Sorting base to ogive is good when the bullets are flat base, but for boat tail bullets sorting by bearing surface should matter. The more or less the bullet comes in contact with the rifling should affect the pressure and therefor muzzle velosity. Uniforming meplats should bring the bcs closer together, then tipping should add back some of the bc lost due to uniforming the meplat. After doing all of the above, sorting by oal may be important(I think so) and last but of least importance is weight sorting, for example, .2 gr variance on a Sie 142 is .0014084 or .14084%.
However,all of the above will be useless if the tools used are not accurate.
 
Maybe one brand of bullet is more consistent than another brand.
 
I weight sort by .10 grains on a lab scale. Then I sort those by bearing surface .001". With Bergers and SMK's I meplate, hole uniform then point. With the A-Max's I just do the sorting and shoot.

I keep fairly good data on the sorting and some brands do sort much better and it will vary from lot to lot. For the non custom bullets the SMK's are the worst and the Bergers are better but not the best (see http://benchrest.com/forums/showthread.php?t=59526&highlight=sorting+data ) but the best non customs I have ever sorted with these methods are by far the 208 A-Max's! :eek: I know, I couldn't believe it either...let the flaming begin!
 
I can believe it. I shoot a spacegun in .223 for Highpower and Long Range, and initially tried sorting 75 gr A-Max and BTHP bullets, but they were extremely consistent - even between lots. Weight varied no more than 0.1 gr. OAL and bearing length varied 0.001". Concentricity (bullet in lathe collet, gauge at tip) was <0.0005". Diameter varied <0.0002". In short, there wasn't enough variation to make it worth doing any kind of sorting.
 
Robert Whitley

Robert
To add to what has been posted.
You can measure the bearing surface length.
You can measure the boattail length and its runout.
You can measure the ogive length and its runout.
You can measure the depth to the lead core using piano wire held in pin vises.
You can use a loop or microscope to check the heel of the bullet for nicks and gouges.
You can spin them on a Juenke machine.
You can trim the meplats but only if you deburr the outside edge after doing so.
On the weight question I sort mine using a exterior ballistic program.The program must go in small enough increments to be useful.The JBM website does not work in small enough increments to be useful.

If you have two bullets with one weighing 215.2 grains and one weighing 214.7 grains this is how to check them.
If bullet #1 weighs 215.2 grains and we expect to shoot it at 3000 fps with a bc of 0.615 you can calculate how much slop you are willing to live with.
Take the square root(215.2/214.7)=1.00116 and multiply it by the original velocity of 3000 fps to get 3003.5 fps for the 214.7 gr bullet.
You can do the same thing with the bc numbers to see what you are willing to live with.
Lynn
 
Robert: I use a tool that is made by Bob Green from York PA. It measures from the tip end where the bullet seater hits the bullet to the ogive. Since useing it I have all but eliminated flyers.
Bob
 
You must log in or register to reply here.
Back
Top