Questions on weighing, measuring, sorting bullets

[youngtrout]

Well, I"m finally working on some loads for my Hart barreled, trued rem 700, 300 win mag.

So far my better preformers for powders have been RL22 and IMR4350. Mainly using 180 nosler accutip? But have been using Hordany 180 accubonds, they seem to be grouping well, and cost a lot less. As for use of the rifle, I have access to a 600 yard range so that will most likely be my upper limit until I find another range

I have only 100 rounds through the rifle, mainly getting fire formed cases out, and breakng in a barrel. I do notice the occasional flyer through (not ruling out shooter error) but I want to start looking into measuring and weighing bullets to start making better reloads.

With that background I was wondering about peoples methods,,,,I sat down with 70 hordany bullets (all I had on hand) last night and weighed them first, ranged from 179.1-180.1. So now I have them sorted, so started measuring for ogive,,,,,now I have them broken into lots in specific weight and lengths, problem is now that you start grouping them I get 3 of one 2 of another, 1 that doesn't seem to fit anywhere, etc.

I realize that if I had started with 1000 bullets then I would have a larger pot to pick from, but I'm courious what others do, and what tolorances are deemed acceptable, example, does bullet weight trump ogive, do you group ogive within .005 or .002, same with weight.

I see the method in the madness, but I'm trying to find the best method to incorporate it into my reloading, it would seem that grouping just into weight or just into ogive, while removing bullets that fall too far out of the "average" Or reloading small lots?

Thanks

 

[youngtrout]

I did some additional reading on Sinclair website, acutally what really had me questioning my above post.

I read down into the comments portion and gleaned a bit more useful info.

His idea of keeping the bullet range to 1% or so and separating ones that fall out of that range,,,then grouping the lot by ogive,,,,,maybe in 4 lots or so.

I think what its really going to come down to is going through the process then loading these up some and see what real world results come of it,,,,,, interesting stuff though.

As for a test though out of my 70 bullets found 3 that were identical, weight and ogive, I then found 3 cases that were identical in weight after fireforming and trimming, loaded these up,,,,,I guess seeing how these group at the next range session,,,,,kind of my test group

 

[Chas1]

Keep us posted on how they group.

 

[lever-hed]

IMO, sort by ogive. Then take some steel wool and see if you can 'wipe' off the .1 gr differences in bullet weights. Depending on how many you need for a match or target practice or whatever, would tell you if you have to increase the pool with which to stock pile a batch. If you need 100 rounds, or 500 , will tell you that you need a much larger pool of bullets to sort and select. Some would say don't worry about the weight as variances in scale readings due to accuracy or the like account for the differences you have no control over.. think of it like this, wind will undoubtedly be a major factor in POI, are you going to fuss over 1/10th gr bullet wt or are you going to focus on something that has more impact on accuracy such as throwing charges , case capacity/dimensions, marksmanship, etc. It's a game of numbers. And, then again if it makes YOU feel better, then by all means..

 

[Chas1]

Then take some steel wool and see if you can 'wipe' off the .1 gr differences in bullet weights.

Good tid-bit never heard that idea before.

 

[Bart B]

I've shot 30 caliber Sierra Match Kings into 1/2 MOA at 800 yards and 5/8 MOA at 1000 yards testing loads with 15 to 20 shot groups. Those bullets have a 3/10ths grain weight spread, about 9 different ogive shapes (as seen on an optical comparitor) and vary in length by several thousandths of an inch. Checking them for out of round at the heel, they do vary about 1/10,000th or a bit more from being perfectly round. They're fine for me. All those tolerances are normal; Sierra doesn't mind a bit as their good match bullets would shoot into 1/4 MOA at 200 yards. Bullets get upset a bit as they slam into the rifling then get squeezed down going into rifled barrels with groove diameters a bit smaller than they are which is best for accuracy; that's gonna change their physical dimensions.

All the perfection one can sort bullets by using static measurements is a waste of time as far as I'm concerned. I think the best way to test bullets is to spin them at 30 to 40 thousand RPM and use the ones that don't wobble; those that spin true without any wobble will shoot very tiny groups at most any range.

A friend spun several hundred Lapua 30 caliber match bullets in a collet chucked in a Dremel Moto Tool. An amp meter was connected in line with its power cord. Bullets that were a bit unbalanced at 30 thousand RPM loaded the tool's bearings more with centrifugal force so more current was needed to spin the motor up to speed; minimum current meant perfect bullet balance. About a third of those bullet spun perfectly. A few were so out of balance they flew out of the collet bouncing off the ceiling and walls in the room.

Those dynamically tested bullets were loaded in full length sized cases and shot in match rifle whose barrel had a standard SAAMI chamber. Several 10-shot groups were shot at 600 yards. Groups ranged from 1.5 inches down to about .7 inch. Those bullets had about the same static measurements for weight, diameter, length and ogive as the Sierras I measured had. Bullets with average wobble/unbalance shot about 4 to 5 inches at 600.