Sorting brass by weight..

[3-0-hate]

I've been reloading for right close to a decade now, but only in the past year or so have I been reloading for long range accuracy, and I have a question before I spend a bunch of time on some brass that might not be worth it.

So I finally got around to swaging all my military once fired .308 brass. I decided that since I have a fair amount of WCC '07 NATO stamped brass, that I would sort this particular head stamp by weight and use it as my competition brass.

Most of it weighed out around 178-181 grains. My question is this, I had a few of the pieces weigh out to 175-176 grains. I know that 1 or 2 grains would likely not have that big of an effect on velocity, and consistency, but what about 5-6 grains of brass variation?

What is the normal window for good brass weight variation? I know this isn't Lapua or something like that, but my inquiring mind would like to know before I start uniforming the primer-pockets and flash holes and doing a bunch more prep work on brass I shouldn't be using.

Thanks!

 

[JGorski]

Re: Sorting brass by weight..

Load some up with the furthest weight between them, see what happens. Im thinking you wont notice the difference.

 

[BigSky Ammunition]

Re: Sorting brass by weight..

SVThuh,

We get this question a lot.
Its a very touchy subject with lot of shooters. We load for over 200 Bench Reset shooters. This is where the subject comes into play the most. As a avid Long Range Shooter on the bench an the field its good to have supportive data.

We took 3 rifles and 1500 rounds of same head stamp brass for each rifle. We broke down the 1500 rounds into groups of weight. We had the .1 .2 .5. 1.0 and even upwards of 3 grains difference, We loaded the same load for each. We found a Median that worked in each rifle. Our Testing was done at 100-500-1000 yards. We took out controlled data from the brass we started with and started using it in the brass we had grouped, it was not tell we reached the higher end of difference 3+ grains per case we noticed a difference at 1000 yards. Our 100-500 yard testing showed no change in groups(20-5 shot groups) per load at given range. So when you hear a Bench rest shooter say it makes a huge difference on there brass at 1000 yards .25-1/4 inch is a huge difference to a bench rest shooter because its only half that sometimes that will make or break a world record. So in short. My bench rest shooters are split they like to see there brass under the 2grains per case difference, some like to have matched weights with in .4 case to case. So if you want by all means do it. So if your looking to break world records on the bench and feel you need to by all means do it. Where you will see the difference is in Manufacture Difference's, Lapua brass is some of the finest out there and we see a 1-2 grain in some of it. If your only going to shoot one head stamp and your shooting for fun or even competing in field matches, its completely up to you. What it comes down to is try it. sort 20 out with in few tenths and ten 20 that are grains difference an see what you see.

Thanks for reading the short story.

BigSky Ammunition

 

[3-0-hate]

Re: Sorting brass by weight..

Guess I have some load development testing to do..

I usually only shoot field matches that are out to 800 yards at the most, and that's a bit rare to be honest.. Most targets are in the 100-500 yard range, and they are usually 12" plates. Sounds like I wont see much change in my POI at those ranges..

I'm sure a 5 grain swing in brass would still make my ammo more accurate than my abilities, but when you can take any advantage you can get.. Looks like I'll be doing a POI test soon.