First, let me say that if you have anything better to do with the next three minutes of your life---scrub the toilet, for example---you should go and do it.

Last year, I started a thread on weighing Winchester .308 brass. Here's a link to the thread. In short, the results of weighing 200 pieces of Winchester .308 brass where:

156.1: 1
156.3: 2
156.4: 2
156.5-156.9: 9
157.0-158.0: 118
158.1-158.5: 36
158.6+: 36

I learned a great deal from the many useful comments made, and I have now full-length sized, trimmed, chamfered, and deburred the cases. I then reweighed all the cases. Here's what I got:

156.1-156.9: 43
157-158: 111
158.1-158.5: 28
158.6+: 20

The bottom range further divided as follows:

155.9: 0
156.0: 0
156.1: 2
156.2: 4
156.3: 1
156.4: 4
156.5: 3
156.6: 6
156.7: 12
156.8: 8
156.9: 2

So I've decided to do what I 156.5-158.8, which is now 170 instead of 163 cases.

It's also interesting to note that the whole weight distribution shifted down a bit.

I'm definitely just buying the Lapua brass next time.

LWD

So, what is the volume of 2.5 grains of brass?

If I read my numbers right. Brass is 8 times the density of water. So 2.5grs would be .3grs of water capacity. QL shows the 308 as 56grs of capcity so you have 56 to 56.3. Sorry if I'm calculating correctly not enough diff for me to worry about.

Well, OK, nevertheless, I love Lapua brass.

But, honestly, I shoot a lot of Winchester brass with no noticable problems.

It's just that I noticed the Lapua brass is super good stuff. I have used quite a bit of the Norma brass too, and find it to be as good as the Lapua brass.

Yet, I still have no complaint with Winchester brass, and the price is better. Heck, I even use some Prvi brass.

Frankly, I don't know if I have the skill or patience to really test the differences in brass. There probably is a difference, but IMO it would take a very accurate rifle to properly test it.

But, again, even with my limited skills, I can tell the Lapua and Norma is super good stuff.

KB

quote:

Originally posted by LWD:
I'm definitely just buying the Lapua brass next time. ...

Hey LWD, Just looked at the Link. That was a lively thread.

Any chance you have tried Weight Sorting "any" Lapua cases? Just curious how consistent they are.

Best of luck to you.

Because I shoot 600-1000 yard benchrest, HC, I sort my brass.

Into groups within .5 gr difference.

Of the last batch of 200 6.5x47 Lapua cases, more than 150 fell into one group.

Yes, 6.5x47 Lapua cases are much lighter than .308, but of my last batch, all fell within one grain.

Best,

flaco

N.B. To be honest, I don't really know if this kind of sorting is effective. Just like I don't know if measuring bullet bearing lengths, or lengths to ogive, or meplats, or turning necks, or annealing cases, or pointing bullets, or seating depth is effective.

Belay that. I take it back. I can tell you with some confidence that if you're shooting Berger VLDs, seating depth is important.

I can tell you that the guys I'm shooting with are doing many, if not all of these things, and I don't want to lose because I was too damn lazy to load good rounds.

Yes, that was a lively thread. I was ducking for cover!

I have not weighed any Lapua brass. I'm not sure I will go through all this ever again. I don't shoot competitively. This was the first time I'd loaded for something other than a hunting rifle so I thought I'd play around with it a bit. Very interesting stuff, and I learned alot from the exercise and all the comments I received.

LWD

quote:

Originally posted by LWD:
First, let me say that if you have anything better to do with the next three minutes of your life---scrub the toilet, for example---you should go and do it.
LWD

I have nothing better to do at this point so I will post a rule of thumb that I was taught when becoming a competitive shooter....

To achieve the same velocity in different weight cases, multiply the difference in brass weight by 0.12 to determine the change in powder charge. Lets say you developed the load in a 156 grain case and want to use a 158 grain case, reduce the charge weight by: (158-156)x .12 = .24 grains.

The only problem is ------- how do you know that the weight variation will cause a difference in case volume? Depends where the weight is!!!

Figure that out and you are making progress.

quote:

Originally posted by Boss Hoss:
The only problem is ------- how do you know that the weight variation will cause a difference in case volume? Depends where the weight is!!!

Figure that out and you are making progress.

Actually you ARE making progress understanding that the decimal .125 = 1/8 where the specific gravity of water = 1 and the specific gravity of brass is about 8.
Just because the extractor groove and areas behind the primer pocket may have more or less brass does not mean the information is not valid.
If you really want to know the volume behind the pressure ring you can measure it directly or by displacement of a fluid.

quote:

Originally posted by LWD:
Yes, that was a lively thread. I was ducking for cover!

quote:

...I'm not sure I will go through all this ever again. ...

Sooooo..., off in the future, if a Flier appears on the Target, do you think you will wonder "if" it could have been eliminated? "If only I'd xxxxxed - the Cases?"
-----

Hey Flaco, Thanks for the report. Looks like they are indeed pretty consistent. Still a bit $$$steep$$$ for me though.

I primed some of this brass over the weekend. Wow, the primer pockets were inconsistent. Some felt almost too loose. I couldn't really feel the primer going in at all. Others were so small that the primer could barely be seated and some couldn't be seated.

Lapua here I come.

LWD

I used to think that good , weight sorted brass would make a difference in accuracy. This last week changed my mind.

I finally got my 22-250 back and loaded some loads picked out from a 300 yard Audette ladder. I went through my brass that I've had for 20 years that I collected indiscriminantly; all brands mixed up but primed and ready to load.

The rifle shot .4" groups at 100. I shot out to 600 and was amazed at the accuracy.

It has a medium-heavy contour Walther barrel.

My point is that you're better off spending the $ on a good rifle than wasting time weight sorting brass.

It depends on your goals, RC...

I took 600 yard small group honors for our club's 2009 season with back to back 1.5xx" groups.

When I test loads at 100 yards I'm looking for .2xx" or better.

Then again, I'm shooting a Barnard P action, Bartlein barrel, and a Shehane MBR Tracker stock. Which is to say I've already purchased a rifle that will compete anywhere.

So I'll continue to weigh cases.

flaco

N.B. I applaud your Walther barrel, RC. I used a long chambered Walther 6.5x55 barrel with a 1909 Argentine on my second project, and that rifle would shoot .300" at 100 yards.

Walther cuts a good barrel.

If one is using a rifle made for high accuracy competition, he should be buying brass that doesn't really need weighing. And if you do weigh, it's just chicken soup.

Just to look at this question from a 'nother direction...

One can "match prep" brass in many, many ways.

The object, presumably, is to maximize consistency of the brass and thereby minimize variations in internal ballistics, for the ultimate purpose of better accuracy.

My own experience in shooting benchrest with state of the art rifles was that regardless how carefully and throughly brass was prepped, some pieces of brass still produced "fliers" when used...that is, shots which for some unexplained reason went other than where one would have anticipated, everything considered.

So, how do you eliminate fliers? Probably there is no 100% fool-proof effective way.

What I eventually ended up doing was minimal brass prep...uniforming lengths, neck thickness, and primer pockets.

Then I would take my rifle and the prepped brass to the range, load each case with a known good load for that rifle and barrel, and shoot groups with the brass. When a shot was fired which went out of the group, I'd set that piece of brass aside. Then I'd reload all the brass and try it all again. If the same cases placed a shot out of the group unexpectedly again, then I'd reload those pieces yet again and see where those shots went a third time relative to the group.

Net result - Out of 100 pieces of brass, I'd end up with 40-60 which always shot their bullets into the bug-hole of the group. Those would be designated as my competition brass.

I'd also have 5 to 15 which would shoot their bullets WAY out of the group. Those would go into the scrap pile.

Those not good enough for match use, but not bad enough to scrap would be used as "Maybes". That is, Maybe I wanted to shoot a prairie dog out by the barn. Maybe I'd need to shoot a coyote out in the pasture...Maybe I'd want to do a little casual shooting with an acquaintance to show him how BR rifles are fed/used.

Anyway, the 40-60 match brass were enough to wear out a barrel with in competition, and there was no arguing with the results. Regardless of WHY the match brass performed to match levels, it did. That was good enough for me.

Ah yes, AC. fire culling. No matter how much you tinker with your brass beforehand, sooner or later you have to shoot it.

I do it not only I personally believe it helps…. But frankly, I enjoy doing it (weighing and sorting brass).

That said I stand by my belief that you must not only trim and chamfered, the necks, you must deburr the flash hole and uniform the primer pockets… then you have a shot at uniform brass by weight.
Just sayen