Home Forums Hunting & Shooting Competitive Shooting Varying weight on brass

I’m waiting for some Lapua brass, in the mean time I prepared some Winchester brass (308). The brass is clean and trimmed to 2.05” The weight of the cases vary from 152 grains to 165 grains. I plan on throwing the outside weights away. Most of the cases weigh between 158 grains and 160.3 grains.

How much weight variance would you allow?

If I remember right, in the Precision Reloading book, they said 1.5% weight. I may be wrong as it has been years since I read that. I have a buddy that sorts his into .2 gr increments
I don't throw away the ones that are outside the limits. I save them and use them to set up my dies, for fouler shots, etc.

Thanks for your reply pullit

For what use?

Good question. However, the OP messed up in the first place by using Winchester brass. Its been total garbage for quite a while now. I tried some red and black bag, labeled as "match" 308 a few years ago and found nothing but inconsistencies with it. Better off going with just about any other maker out there. Lapua, Hornady, Starline, LC, even FC, etc. etc. Sig Sauer is also making some pretty good brass for the money. Bought some at Cabela's a few years ago, to try and that stuff keeps on going. Use it in my 22-250 as well. To each their own, but I wouldn't be using WW, not even for hunting. Let alone any type of competition...

Still waiting on Lapua brass to show up.
I had a pile of different kinds of brass. I was surprised to find the weight variation on Winchester brass - while most fell into two groups 158 to 160 grains and 156 to 158 grains. But there were a few from 165+ to 151 grains. So while waiting for the good brass to show up I decided to look for other brass. I found I had a couple hundred LC Match, a hundred or so of BHA Match and a hundred or so of Hornady Match brass.
I’m currently getting them seriously clean, trimming and weighing them. I’m also tempering the necks with flame method. The match brass is once fired.
I’m curious though about primer selection. Most people seem to use Federal 210, why not 210M? Are they available?

The purpose is this:
I bought a never-been-fired, gun smith built bench gun built on a blue printed 700 action. I have always worked hard on getting the best accuracy out of my rifles - 90% which are 700’s, partly because I’ve found them to be accurate factory rifles. I’ve tinkered with each one, doing the basic tricks to get best accuracy and spend hundreds of rounds to get the best accuracy - being pleased with 1/2 MOA and excited with 1/4 MOA groups with my big game rifles.
This is my first bench rifle. I want to see what it can do and what lessons I might learn along the way to get optimum accuracy. I want to get in the 1’s.

My former 308’s that I’ve owned primarily were carbines (600’s & 660’s). I’ve owned one heavy barreled AR-10 style rifle and I still have a Berga in a 308.

(I have lots of FC brass I could try???)

Do you know the chamber/throat dimensions?

Now that’s a far fetch. Damn was at sportsman’s saw new guns with powder residue on the muzzle. Hell even Cooper fires 3 rounds. If your smith hasn’t test fired, dumb.

years ago I sorted cases by their capacity. I took fired cases with the primers still in, filled them with ball powder, and then weighed the charge. I was sorting .223 cases and found that for every .1gr change in capacity, the case weight changed .3grs. There were people saying to segregate them by .5grs and that seems just a bit tight for me. I feel that sorting them by 1 gr increments is about as fine as anyone needs even in a case that small. Unless you're right on the verge of a compressed charge, sorting finer than that is a waste of time.

Sorting by case wall thickness just ahead of the web is my starting point now. That's a much more critical factor in my experience.

The rifle, as I understand it, the gunsmith could not finish testing etc. I think he died or serious illness - the seller didn’t explain. I ran a foaming cleaner down the bore - result no copper no powder residue, just some grease. The barrel is stainless steel BTW.

The weather here has been quite nasty with high of 0 degrees or lower for a while. Winds have been up to 50 MPH. On top of that I’ve had back surgery earlier this month. So I’m doing all the prep work I can — until I can carry the rifle to my bench. The rifle is about as heavy as the doctor will allow me to lift.

By the time everything is ready I hope to have all that I can get accomplished. The rifle remains unfired for now. I own a neck trimmer, diameter and OA, I used to compete in just about everyb rifle and pistol competition, but never bench.

I appreciate your advice on brass, bullets, powder etc. I figured that this group might be able to give it.

The Lapua brass arrived today.

I bought some 168 grain match kings - hollow point. I have a good supply of powder, no Norma though.

How critical is primer selection?

It just occurred to me that I have not even measured the twist yet.

Interesting. Sounds like fun. So, I'm assuming you have a concentricity gauge? I wouldn't take another step forward without having one and knowing you are loading straight ammo. So many variables involved in making good accurate ammo. A true benchrest rifle would be very cool to play around with. Keep us posted on how she shoots. Good luck with it Bugger..

Most powders have about 1/8 the specific gravity of brass. A variation of .2 gr powder charge is a volume change similar to a volume change equivalent to 1.6 grains in the weight of your cartridge cases. Most of the variance in brass weight is due to the extractor cut.

+1

If you sort by weight after you turn necks to uniform the lot and deburr the flash holes consistently then aneal the necks....you'll be as close as your brass will be capable of.

One of the best things about Lapua brass is the neck tension uniformity. It is obvious that they aneal their brass and likely have a better draw/die system.

save the outliers for your foulers...

Took 400 rds of RP 22-250 once fired and anal prepped brass. Weighed and sorted out the 100 closest to the mean, and the rifle became a 1/2 minute unit.

I e been weighing different makes of brass. I was surprised that some were quite consistent on weights while others were all over the place. I’ve thrown away close to 60 brass and I’ve just started.
Some vary as much as 10 grains. Another set varies by 1 grain.

Pard bought 100pcs of Norma 6XC and it deviated 7grs. He went Alpha 243 Kreedmire(prior to Bob offering 'XC) and never looked back. Hint.

I prefer Alpha to Lapua and in 308 I want LRP. Hint...............