Thread: Bullet weight sorting

Was up the range doing load work for my new .338 Lapua over the weekend.

My aim was to run in the barrel with a cheaper load using a mid charge under a Lapua 250gr Lock Base then to carry out some initial load testing using AR2225 and Hornady 285gr ELD-M The Hornady sure didn't break any records for accuracy. Only 3 shot groups and very early days.

When I got home I decided to weigh the bullets I had left (and some others) as you can see the Hornady which were the most expensive bullets weighed were the worst for consistency. So when your bullets are as inconsistent as this the best powder scales wont help you. By culling a few bullets your chance of smaller groups especially at a mile will improve. That very light Berger would screw you up at long range So will I weigh my bullets from now on well unfortunately yes.

What did you weigh them with?

Now I'm afraid to answer yours might be bigger than mine. PACT BKII

Im no expert in this but sounds like you are looking in the wrong area for a problem. 0.1 of a grain is 0.04% difference in weight. 1 grain is 0.4% difference compared to the 250gr rated pill, even less compared to a 285. Sure it will have some effect but its probably not worth thinking about. 1 grain spread in a 55gr .223 pill is almost 2%.

I FL size. Weigh my powder on a balance scale to the same level and seat my projectiles and most are +/- 0.02mm and get 1/2moa groups when I do my part for my 260 and 308. I understand everything you can do will help improve your groups but if you think about how much of a difference that variance in weight is. How much time its going to take you to sort it into weight batches, will you shoot all weights or discard the extreme spread? What distances are you shooting at and what level. ie national competition etc?
would playing with charge weight or seating depth first be more worth while?

Ah I didn't read the mile part.
I would discard the ones well outside of the mean and use them for load development at closer ranges.

I think you maybe causing yourself extra headaches Jeremy. With a jacketed bullet there will always be some variation because of the lead. That’s why there is this new big interest in solid copper bullets for elr. The 285 from what I’ve heard don’t seem to work in every rifle. I am going to start doing some group testing and will ge at sparrowhawk this weekend so I might try a grouping at 1000m + with the 285. Like I said to you earlier from everything I be learnt from the 338 the 250 and 300 lapua scenar are the easiest to get to work in most rifles. Ive never weighed any of mine and only seen about a foot of verticals dispersion at 2km. Wind is the hard part.
Good luck with it. Try a 10 round load development. 7 round ladder test at .5gr increments as smaller amounts amount to stuff all in a 338 lapua case. Shoot them to same point over a chronny. Take the velocity flat point at the desired speed and pressure showing on the primers. Then load 3 and you should have single digit sd and a decent group. The 338 may take a bit of time to get shooting groups less than 1” if you normally shoot light calibers. They exaggerate everything in your shooting fundamentals. In elr a 1/4” group with a 50 FPS velocity spread will hurt vertical accuracy at 1 mile

You’d laugh at this, I was at an nzda meeting last night and called bull shit. A guy was selling a Weatherby hunting rifle in 338 win mag. With a box of 200gr Winchester factory so ammo. And a vx2 scope with 2 hold dots. Reckoned the guy who owned it shot a 8” gong at 1000m in 3 shots. He must be either the luckiest or best shot around. I’m thinking neither. But I maybe wrong. Bet it was probably about 300m as he maybe didn’t have a rangefinder.

I’d be happy if I can do this with the 338. Shot this just before heading to the alpine match the other week to check my ammo I had just made on the range by my house. Target was 750m. Shot with my Dan hardy 300win mag. One of his early ones built. His action and barrel in a senator stock using 208 eldm.

Also Sparrowhawknz is hosting the next long range match. 25-26 August. Same weekend as gunslinger we’re going to do there before they folded. So if you have airfares booked. Nick will be posting info on his website next week to enter.

Using cheap electronic scales (anything less than $ 1000) for sorting projectiles is a waste of time.

Have a look at the differences between a force restoration balance and a strain gauge type scale...

I have a little experiment for you.

Go ahead and weigh your projectiles. Label some bags carefully, and store the projectiles in them.

Come back an hour, or a day or a week later and weigh them again. See how much consistency you get...

Litz (Applied Ballistics) has done quite a bit of research on factors affecting accuracy, and you are better off:

1) buying projectiles that come from a manufacturer that has better quality control i.e. Berger
2) if you have the time and patience to sort projectiles, do it by bearing surface length.

[QUOTE=ebf;704583]Using cheap electronic scales (anything less than $ 1000) for sorting projectiles is a waste of time.
[/QUOTE

What he says mate the accuracy of the bbk2 is .1/.10 grains for under 300 so wasting ya time mate.

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Hi Cowboy I have picked up a box of Lapua Scenar 300gr to try on my next range session. It is very early days with only about 50 rounds down the barrel so when it settles down I am thinking things will improve. A 3 shot group of .3" is not bad but I am sure 10 shot groups after at least 100 rounds will start to show the potential of the Hardy barrel. I would love to get down for the Sparrowhawk shoot however I am attending an Accuracy First 3 day school in Texas in September so funds are going towards that.

Ebf I don't agree with your views on the scales. That it shows some manufacturers projectiles more consistent than others is proof that there is accuracy there. I will take you up on the challenge and keep you all posted. I agree with your thoughts on quality control the results show Berger are very good however isn't that a perfect bell curve for the Lapua Lockbase.

Thanks for both of your thoughts guys

@Dermastor, there is accuracy in projectile weight for sure, but there are other factors which may have more impact...

Simply because you think you've seen some consistency in weight measurements does not mean that is what actually causes the accuracy. It may well be that those projectiles also had a similar bell curve in terms on bearing surface and/or several other criteria...

An old rule of thumb in metrology is to use an instrument with prescision of one decimal place more than what you are trying to measure. So if you want to measure length to a thousands of an inch, you should be using a tenth micrometer for decent results. Same thing applies to weight measurements. You will not get repeatable, accurate measurements weighing to 0.1 grain with a scale that has a prescision of 0.1 grain. Add to that the tendency of strain gauge scales to drift (by up to 0.4grain), and you will start to understand my waste of time comment.

Looking forward to your results, and have fun on the course, TH is well worth listening to.

The weight consistency is well inside one grain, even if we include the Berger "outlier".

0.8 grain difference is about the weight of a drop of water. Most scales should be able to deal with this, maybe not accurately, but scales are good at picking up differences regardless.

So I reweighed the Lapua Scenar 300gr bullets. Yes there was a different result the second time around, however a similar trend of weight distribution remains and to say it was a waste of time ignores that fact that I'm not that interested in the actual weight but how close they are in weight to each other and the 2 weighing's show this result. We all have budget restraints budget so make the best with what we have

@Dermastor,

Thanks for the interesting posts.

So... if your budget is fixed but your time is not... you now scrape lead out the bottom of all bullets, in a concentric fashion, until they are all 299.6 grain. Doable. And the jury is out forever debating if it will be worth it. But your results have the final say.

Don't know about scraping the bottom of your bullets. I was told never to touch the bottom as this was the most likely to effect accuracy!
Case in point being two bullets. One with a small dent to the head and the one with a small scratch across the base. The second one was the flyer. You can try this. I have never bothered as there are so many factors that come into play in the accuracy game.
But I'm always very careful when seating the bullet not to scratch/scrape the base.
Is it doable if your a true bench rest shooter? Yes/No?