Bullet sorting by weight - how far to go

  • 3K Views
  • Last Post 16 January 2015
Pentz posted this 13 January 2015

Yesterday's casting session yielded 400 NOE 312299s from a 4-cavity mould that fell between 200.5 and 202 gr.  Using a digital scale, I sorted them into fairly even lots of 200.5 - 200.9 gr; 201 - 201.5 gr; and 201.6 - 202 gr.  The few outliers above and below were discarded.   Overall, the variation was less than 1%, and I wonder if the segregation is significant, considering the diameters are all within 212.0 - 212.6 diameters.  I'm sizing to .311.   What do the rest of you do?

Attached Files

Order By: Standard | Newest | Votes
onondaga posted this 13 January 2015

I don't sort for weight until after I get a load that groups well. My reason is that the variation in bullet weight actually helps locate a broader sweet spot for the charge. I will only sort to 1% after I find the most accurate charge with unsorted by weight bullets.

Gary

Attached Files

norm posted this 13 January 2015

Pentz, Now you should cast another batch but don't weight segregate them. Then shoot a significant number of groups with each batch and see if sorted or unsorted bullets shoot better.

Attached Files

Pentz posted this 14 January 2015

I need to work on loads for 4227 and/or 5744. My 2400 is too precious for competition this year to expend much on experimentation. Sure hope there is a big production run for 2400 soon! Thanks for the suggestions.

Attached Files

RicinYakima posted this 14 January 2015

I am getting ready to sort bullets for this years Military Rifle nationals. Depending up what the curve looks like, normally I do 0.3 grain lots. I do not think it is that important, but weighting them on a digital scales, it is just as easy to sort by o.1 grains. I cast normally about 300 visually match grade bullets in an afternoon. It is common to get groups of 10 to 20 exactly the same weight. Why break them up? Those will all be shot as “group” bullets. I am really just weighting to sort out the light ones with holes or slag inclusions. HTH, Ric

Attached Files

John Alexander posted this 14 January 2015

I second Norm's suggestion.  Except for the first few bullets out of a cold mold, if I maintain a uniform casting cadence I have never found a  reason relating to accuracy for sorting bullets by weight. If you simply like sorting bullets or if it gives you confidence, in spite of a lack of evidence that it improves groups, by all means sort away. People like to pursue this hobby in different ways and that's how it should be. 

If you don't have enough 2400, use something  else to run the experiment and shoot a minimum of fifty shots of each to avoid thinking you have found a difference in group sizes when you haven't.  If you have no powder at all you have a good excuse for staying in the dark and taking other people's opinions. 

 I have run the experiment Norm suggests a number of times and in my trials the the unsorted bullets shot better than the sorted ones about half the time.   If I could generate any evidence that sorting improves groups, I would sort bullets into .1 grain batches because that's as fine as my balance will discriminate and I will do almost anything to shrink groups  -- but I haven't been able to find any such evidence and don't believe in magic. 

I know this is a radical position and I am always worried that it may offend someone but I have suggested that CB shooters run the experiment and see for themselves if I am right or wrong.  But as far as I know if anybody other than Norm has tried it they haven't reported their results. 

 John

Attached Files

onondaga posted this 14 January 2015

I agree with you and the sorting I do after finding the accurate load with unsorted bullets is only a preference of mine.  I do believe unsorted bullets do show where the center of a broader sweet spot for the charge is, but the expectation that sorted bullets will make groups smaller is only an expectation.   I see no difference on paper but the sorted bullets do add a confidence factor that I prefer. Gary

Attached Files

John Alexander posted this 14 January 2015

Never underestimate the value of confidence. John

Attached Files

Paul Pollard posted this 15 January 2015

For the last several years I have not been segregating bullets by weight. I've used the scale more for a process control tool. My PACT scale which reads in .1 grain increments quit reading properly (scrambled read out). The replacement scale reads in .02 grain increments. 

I'm not shooting military rifles and haven't shot a .30 caliber for about 9 years. My Eagan 6mm single cavity brass mould casts a linotype bullet at around 79.5 grains. The last batch cast with it shows that it cast a ridiculously close range of weights. With gas check and lube, the range was 81.00 to 81.20 for 213 bullets. If I rejected 17 bullets (2 from the high end and 15 from the lower weights, all the remaining 196 bullets are in a .1 grain range. That's equal to 92% of the total. The new scale helped me to see just how close the weights were.

Part of the reason for the narrow range was taking the time to bring everything up to operating temperatures and keeping a consistent casting cadence. Just by putting a cold dipper in the melt made the temperature drop 30 degrees. Waited for it to come back up to 625F. When the dipper was hot, the pot temperature came up. The mould dropped good looking bullets at first, but I only started keeping them when the mould felt right.

This is not a 4 cavity mould and my bullet weights are about one third the weight of the .30 caliber. 

Attached Files

John Alexander posted this 15 January 2015

Paul, What brand and model is your new scale? John

Attached Files

Paul Pollard posted this 15 January 2015

John, It's called a MyWeigh GemPro 250. Found mine on Amazon. This one only weighs to 750 grains, but has the .02 grain increments. They make a GemPro 500 which weighs to 1500 grains in .5 grain increments.

I felt that the finer increments would work better with my smaller caliber bullets. I had suspected for a time that the PACT scale separated into different weights by averaging. It would shift back and forth between a weight, trying to figure out if it was closer to .6 or .5; it may have been .55, .56, or .54. 

Sent two of the PACT scales back for warranty work. A phone call to them indicated that they might be too busy to work on them for quite a while. Considered getting another PACT or RCBS (made by PACT), but thought the finer increment weighing of the GemPro 250 might be informative. It was.

Attached Files

Tom Acheson posted this 15 January 2015

I usually cast up about 1,000 LBT .30 cal. 4-cavity 170-180-grain bullets, depends on the alloy.

Then all are weighed to 0.1-grains. They are transferred into 100-round pistol ammo boxes. Then during the match season I work my way from the lightest to the heaviest throughout the match season. At any given match I'm probably loading bullets that vary 0.1 to 0.2-grains that day.

The scale is a Dillon digital which is far better than a beam and balance, due to my impatience in trying to get decent “production speed” out of the old balance type. BTW Dillon has excellent customer service!

I do want to find that handful of unusually light or heavy ones so I can set them aside. I get those because I'm not a machine and my casting technique is not near as good as the experts. There are some who will disagree with the weighing practice or think I'm all wet but...I don't care!

Waiting for the January thaw in MN so I can get out in the “garage foundry” and start casting for 2015.

Tom

Attached Files

John Alexander posted this 15 January 2015

Tom Acheson wrote: "I do want to find that handful of unusually light or heavy ones so I can set them aside. I get those because I'm not a machine and my casting technique is not near as good as the experts. There are some who will disagree with the weighing practice or think I'm all wet but...I don't care" Tom, That's the right attitude.  We may get bossed around at work but when casting bullets we are our own boss.

Paul, Since you mentioned problems with you Pack scale thought I would mention that I have had mine for a dozen years with no problems -- maybe just lucky.  Mine also jumps back and fourth before making up its mind.

John

Attached Files

Paul Pollard posted this 15 January 2015

John, I have no complaints about the PACT scale. I'm thinking I bought it in 2000, so it has held up well. The other one was a used one, bought from a CBA member who is no longer with us. I didn't realize it wouldn't stabilize on a readout when I bought it. It was even older than mine and did not have the infrared port for the powder trickler thing.

Attached Files

Tom Acheson posted this 15 January 2015

Guys,

I have to tare the Dillon every now and then, maybe every 5th bullet. But I do that as I remove one bullet and set another on the pan. By the time the new bullet is just over the pan it reads 0.

This is my third one. Each time I had a problem and sent it back for “repair", Dillon sent me a new one. However, this one has worked well for 4-5 years now. It helps to turn it on an hour before you start to use it, requires less frequent pushes of the tare button.

Tom

Attached Files

onondaga posted this 15 January 2015

I have a digital scale that I sometimes use for weighing bullets, but I actually have a balance beam scale that is  faster, doesn't lose zero and settles much quicker than the digital. I have an old Redding #1 that is oil dampened and accurate to .1 gr. It is an oldie but the oil dampening is faster than anything new, digital or analog. The pencil points to the oil reservoir that is filled with mineral oil. The center of the beam has a paddle that goes down into the oil. This thing is super fast at dampening. You can find used ones on Ebay. They are from the 1950s and an old favorite. Gary

Attached Files

Paul Pollard posted this 15 January 2015

The Redding oil-dampened scale was the first scale I owned (half with my brother). Yes, it is good and settles quickly. I'll have to go arm wrestle him for the use of it, though.

Attached Files

Pentz posted this 16 January 2015

I appreciate the comments. For me, weighing eliminates one variable, such as wondering why that one shot dropped out of an otherwise good grouping. It also eliminates some of the oddballs resulting from my imperfect casting technique. That has, BTW, greatly improved due to Pat's PID!! How did I ever get by without it?

Attached Files

tomme boy posted this 16 January 2015

Remember this. It only matters if it matters.

Attached Files

Pentz posted this 16 January 2015

And wherever you go, there you are...

Attached Files

Categories
Search
Popular Tags
This Weeks High Earners
Hot Topics
Close