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Topic: Sorting Bullets (Read 183 times) previous topic - next topic

Sorting Bullets

I'm about 5-6 weeks away from the local Nationals 600/1000 yard event.  I need around 400 rounds for the match and need to start getting ready.  I plan on shooting 105g Berger Hybrids in the Dasher, 115g VLDs in the 6mm CM and 140 Hybrids in the 6.5 CM.  Today, I started sorting the 105g Hybrids.  There has been some discussion on what parameters most useful for sorting.  I am going with first sorting by BTO followed by a sort by weight.  For now, I'm going to let the OAL be what it is.  Since I will point these prior to loading, in the future, I may trim them all to length prior to pointing and remove this variable.  I got thru around 500 today....painful process.

Yesterday, I sorted 250 once fired Alpha cases....so that brass is good.  Need to do the same for the 6/6.5 CM brass.
Bob
If everything seems under control......you're just not going fast enough

Re: Sorting Bullets

Reply #1
I dont see how you guys do that.. lol.. i mean i see how you do it but once you get them all sorted in their batches and loaded then what.. do you have to make scope adjustments for each batch ?is one batches of point of impact different than the next ? Ive dabbled with sorting a little but doesn't take me long to get over it and just shoot them.. lol.. course im not trying to win a bench rest match either..
Grant

Re: Sorting Bullets

Reply #2
It's basically getting them grouped into similar batches so they fly alike. Even in the finest hand pulled bullets there will be ogive variance up to .002" and OAL variance as much as .016" and occasionally you find a real outlier beyond these.
 Finding the real bad few in the 1000 is the real goal but if you're measuring them all you might as well classify them into like batches.

Consistent one stroke of the press seating is a bonus from sorting also.
Dave

Re: Sorting Bullets

Reply #3
If I can load a full set of rounds for both the sighters and the scoring rounds, then as I shoot the sighters I have confidence that when I shoot for score they will be as close as possible.  So the adjustment during the sighter period takes batch to batch difference into account.  Also, as Dave said, you are really looking for the outliers.  I found about 10 from the batch of 500 that were either way out on BTO or weight.  That alone is worth it.
Bob
If everything seems under control......you're just not going fast enough

Re: Sorting Bullets

Reply #4
Have you ever considered sorting based on bearing surfuce?  B2O is good for flat based bullets, but if there is variation in the length of the boat tail, then that would skew your results.
Assuming that shape of the nose of the bullet is consistent in the forming process, then weight and bearing surface (drag on the bore) might be the 'biggest' determiners of bullet to bullet consistency. IMHO.

Re: Sorting Bullets

Reply #5
I've sorted bearing surface before. Honestly I found it extremely difficult to get repeatable measurements.

I spent the better part of a winter a few years ago sorting thousands of custom bullets from 3 different makers. I sorted for the following:

Base to ogive
OAL
Seater stem to ogive
/\ These 3 are fairly easy to get repeatable consistent measurements.

Bearing surface
Pressure ring diameter
Bearing surface was impossible for me to get repeatable results so I saw no point in it. Pressure ring measuring with a bench micrometer was slow tedious work and getting repeatable measurements was difficult as well.

How you sort is dictated by your equipment and what you are sorting for. I believe if a person were to sort to one variable it should be seater stem to ogive. However I've found seater stem to ogive to be dead on consistent (+/- .0005") in custom bullets so there's no point. There are base to ogive variables (.001") and there are OAL variables (up to .016") though. So after you sort enough B to O & SS to O you realize if the bullets are extremely consistent within +/- .0005" from the base to the seater stem that all your OAL variation is from the seater stem to the tip.

If you look at a tip or meplat under magnification you can see it's always where the bullet is closed up leaving the hollow point. At this point you either become a trimmer and or pointer or sort to OAL.

I do know people who sort to bearing surface so I'm not discounting the value of it I'm saying I won't waste time on something I can't make repeat.
Dave

Re: Sorting Bullets

Reply #6
The challenge is to find the things that matter for consistency and then to have methods for reliably measuring them.  The BTO is pretty straight forward to measure and is really focused on consistency of how much of the bullet is seated into the cartridge.  The measurement of bearing surface does not address this but looks to control the brass/bullet contact area.    I don't have the tooling required to measure this....but it could be made.  In an ideal case, having all of factors the same would be the goal.  Each bullet exactly the same.

For now, I'm going to start with BTO and weight.  I do plan on trimming for OAL at some time and then pointing....so that gets three big ones.  If I can figure out some tooling, it may be worth then seeing how consistent the bearing surface is in practice....don't have good sense of how much variation is acceptable.

The Berger 105g Hybrids and the 115g VLD are sorted and ready.  Next is the 140g Hybrids.....
Bob
If everything seems under control......you're just not going fast enough

Re: Sorting Bullets

Reply #7
Just out of curiosity i put a comparator on each jaw of my calipers with a 24 insert on one side and a 22 insert on the other. (Wish i had another 24) i checked some 105 hybrids with the boat tail in the 22 and the ogive in the 24. It onlytook me abot 7 bullets to have a .004 variance.. each bullet i measured several times and came up with the same number every time.. so it was repeatable in my eyes.. was suprised at the .004 variance though in such a small sample..
Grant

Re: Sorting Bullets

Reply #8
As an experiment, take some at each side of the spread, load them and shoot them.   How do they vary in MV and group size?  Does 0.004 variation in this variable make a difference.  Probably need a reasonable sample size to draw any conclusions but should be done before spending a lot of time sorting based on this.
Bob
If everything seems under control......you're just not going fast enough

Re: Sorting Bullets

Reply #9
When I say something is not repeatable or difficult to get repeat measurements I'm not talking about 5 - 10 samples. I'm talking about sorting 100 then going back through the bins to randomly see if some can be found that should not be there.

On the .22 comparator..... The boat tail has a much sharper angle than the ogive so the 22 comparator is actually measuring closer to the BS on that end than a guy would think. Does it matter if it's consistent?

Measuring BS you have two ends you can manipulate with caliper pressure to make it read what you want versus on measuring B to O so in my mind it's her as accurate. With two comparators on a caliper I think they would have to be in perfect alignment with each other, the slightest deviation would skew the numbers in my mind. As Bob said without making tooling I wouldn't waste my time on it even if I thought it was getting repeatable numbers.

I do like to see you measuring bullets though Grant, carry on!
Dave

Re: Sorting Bullets

Reply #10
When I say something is not repeatable or difficult to get repeat measurements I'm not talking about 5 - 10 samples. I'm talking about sorting 100 then going back through the bins to randomly see if some can be found that should not be there.

On the .22 comparator..... The boat tail has a much sharper angle than the ogive so the 22 comparator is actually measuring closer to the BS on that end than a guy would think. Does it matter if it's consistent?

Measuring BS you have two ends you can manipulate with caliper pressure to make it read what you want versus on measuring B to O so in my mind it's her as accurate. With two comparators on a caliper I think they would have to be in perfect alignment with each other, the slightest deviation would skew the numbers in my mind. As Bob said without making tooling I wouldn't waste my time on it even if I thought it was getting repeatable numbers.

I do like to see you measuring bullets though Grant, carry on!

Im not going to measure many.. lol. But i am going to get 4 on the short side of the bs measurement and then put one on the long side and shoot them all into a group just to see what happens if anything.  I should add all the bullets i measured this way was within a .001 on base to ogive..
Grant

Re: Sorting Bullets

Reply #11
Just out of curiosity i put a comparator on each jaw of my calipers with a 24 insert on one side and a 22 insert on the other. (Wish i had another 24) i checked some 105 hybrids with the boat tail in the 22 and the ogive in the 24. It onlytook me abot 7 bullets to have a .004 variance.. each bullet i measured several times and came up with the same number every time.. so it was repeatable in my eyes.. was suprised at the .004 variance though in such a small sample..
When I first decided to measure bearing surface, I actually made a fixture with a base with a hole sized for the boat tail of the bullet I was measuring and another piece for the ogive that attached to a dial indicator arm and the spring tension in the dial was what gave me a consistent pressure on the bullet between the two parts.  Later, I bought a Hornady comparator and the light bulb came on and I bought another for the purpose of measuring bullets.
If your orient the two comparator bodies on the caliper arms the same and tighten them while keeping them aligned then I found the measurements to be easy and repeatable (for consistencies sake, I always put the boat tail into the same compartor and the ogive into the other since they are not likely to be exactly the same).
As to whether it makes a difference...I don't know.  Does the longer bearing surface cause more drag and therefore more pressure/velocity?  Does it just drag on the bullet as it goes down the barrel and reduce velocity? Does the longer cause more pressure and increase velocity and the shorter cause less drag and increase velocity and thereby cancel out any perceived gain from sorting in the first place?  I don't know....
...now my head is hurting...

Re: Sorting Bullets

Reply #12
I have only been sorting by base to ogive, throw them into labeled ziplock bags. Works for my needs, but I would sort more if I had the means to. I don't feel like sorting by weight with my 5-0-5 or 5-10 scale.