Bullet and Case variances - Help for a newb?

[Turk10mm]

To start with, I'm brand new to reloading. In fact, I haven't reloaded a single round yet. My last two shipments of gear arrive next week.

So anyways, years ago I saw a special on Army snipers, I believe, and they showed the armory guys reloading ammunition. They were weighing the cases and bullets and putting them into lots.

So, being the tedious and technical guy that I am I got my new Chargemaster 1500 and started doing something with it. I found that 200 rounds of Sierra 168gr BTHPs had a variance in weight of 6/10th of a grain. I had one bullet that fell out of this range, and it was 167.4.

167.8 15%
167.9 20%
168.0 35%
168.1 15%
168.2 10%
168.3 5%

I also am just finding out that the length of the bullets seem to vary between 1.202 and 1.207 with the median being 1.204

Is classifying these bullets by 1/10th of grain and length going to yield any difference in accuracy. I would think that it might. Probably not at 100 or even 200, but as you start getting further out I would think the variation would start to have an effect.

But then, I know absolutely nothing about this, other than it seems slight variations over long range would begin to show up.

If not, oh well, I wasted a couple hours tonight in front of the tv.

Any help here?

Tony

 

[Victor N TN]

Re: Bullet and Case variances - Help for a newb?

If you want to measure the length of bullets get a Stoney Point (now Hornady) bullet comparitor and dial caliper. Measure the bullet from base to ogive on the bullet. Measuring OAL on a hollow point bullet is going to be difficult. The bullet jackets vary in length a few thousandths and then the forming dies make it a little worse. Bottom line is .015" variation in length on production bullets is about normal. To get any less at all you'll have to go to custom bullets.

Weight is another matter. To measure accurately to 0.1 of a grain you need a labratory balance that weighs to 0.01 of a grain. It just works that way. Every chemist I've ever spoke to explained it that way.

Production bullets may vary as much as 3.5 grains on a 168 grain HPBT style bullet.

Making bullets is kind of my thing. If I don't stop I'll be rambling on into the night.

If you want better, buy custom bullets. But unless you're going to shoot 600 yards or farther in competition, I would shoot Bergers. They are the next best thing you are going to find without going to custom made.

 

[Turk10mm]

Re: Bullet and Case variances - Help for a newb?

Thanks!