New barrel=new Brass? That is the question

[warrenb]

So I have myself a a new .223 caliber shilen. No competitions but I want to be accurate. Here are my choices.

A. I have prepped around 100 winchester once fired brass. After weighing the brass. There is an easy 2.5 grain difference in weight over the 100.

B. I also have 200 rem brass, 6 times fired in my old barrel that are within 1 grain most of em. These have been anealed a couple of times and have given me pretty good groups for my level of shooting.

C. I have several hundred once fired rem brass. And a bag of untouched new.



Now that I have weighed the winchester I would like to continue using brass from B

What would you do?

 

[Doc M]

Well, if you're dead-set on B, then here's what I'd do:

1 - See if they'll chamber in the new rifle. If so, no need to full-length resize. Just fireform, and have at 'er.

2 - If they won't, FL resize, fireform, have at 'er.

My next choice after that would be C, the untouched new. Prep time may make this less favorable to you.

After that, using a subset of "A" that fits in a tight enough weight group could give you 60-80 rounds that you could set aside for "group shooting" purposes - even if they don't hit exactly POA on the first go, they should still group consistently.

This is why I buy my .308 in large (1,000pcs) lots when I can, since I can be ultra-picky and STILL come out with 700+ pieces of 'matched' brass which is within what I consider 'allowable error' from the mean weight.

Also, sorting for ULTRA-precise groupings (e.g. for strings intended for ultra-precise group shooting) as below has worked for me:

What you see is a cut piece of fluorescent lighting "grate" (get it from Rona for about $20 bucks, at most - for an entire panel). Cutting it this way, I can "stack" in 0.1 grain increments - which, with about 145gn case weight (if I haven't forgotten) isn't much variation at all.

You can see how sorting then becomes easily accomplished via looking at the "histogram". I label the weights of each column with masking tape and pen, below the grid - so I can keep things straight.

Out of this one, I made 3 major groups of 20-30 cases each; anything "outlying" was tossed in the "plinking" pile and now gets fed through my Norinco M14S. These groups were basically 0.4gn "wide" or so - giving an overall variation of 0.3%. A 1% variation (so, 1.45 grain or so) would comprise most of what you see in that pile - with maybe 10-20 outliers or thereabouts. So, decide how picky you want to be - and hop to it!

-M

 

[warrenb]

DocM,
you inspired me I'm going with plan C.
I now have a Folgers tub full of full sized Remington once fired LEO brass. I will start trimming tonight. On initial inspection I don't think it will take me long to find 200 that are within a reasonable weight range.

I am amazed how uniform, weight wise, the once fired rem 223 brass is. In comparison the Winchester is all over the place. I have always been keen to use Win brass in my other calibers but if weight commonality is anything to go by, and perhaps its not, the RP stuff is pretty good.

cheers.

 

[Doc M]

I'm happy you've found a solution you're okay with!

Also, keep in mind that what I was weight sorting in the pic above was Lake City 2005 brass in 7.62x51... commercial .308 is even tighter, and commercial .223 tighter than that, I find.

I'm sure you'll be happy!

Then, if you REALLY wanted to, you could do a volume sort by sticking in some spent primers and doing a water-isopropyl mixture/weight differential?

-M

 

[warrenb]

Then, if you REALLY wanted to, you could do a volume sort by sticking in some spent primers and doing a water-isopropyl mixture/weight differential?

-M

Whilst I genuinely respect the proponents of the volume sort. I ain't never going there.

 

[Doc M]

Whilst I genuinely respect the proponents of the volume sort. I ain't never going there.

Yeah, neither am I... yet.

My methods work well enough with my present rifle that I can hit most anything I want to at 600yds or less... and past 600, it's about an 85%er on reasonably-sized targets (1MOA and above).

That's more than good enough for me! Well, for now...

-M

 

[TrxR]

Might be a dumb question but what difference does the weight of the brass make?

 

[hiredgun]

Regarding the volume sorting of brass: Mysticplayer details a procedure that fills the spent brass with a fine grained powder to determine volume. Cases that hold more or less than the average are discarded or used for plinking. The theory is that case volume is what really matters, differences in case weight could be due to a number of factors like a narrow extractor groove that may not alter accuracy. I have not tried this volume system but it seems logical to me.

 

[bearhunter]

warren b, are you using this brass in the same rifle? I suspect you are. This sounds like a nice rig you've put together. Shilen barrels are very good.

I like to use the same brass in each individual rifle. I had two 308Win rifles with barrels purchased at the same time, from the same maker (Canadian). They both shot well under a moa. They both had identical chambers and headspace.

They did not like the ammunition used in the sister rifle.

They still shot acceptably, but the groups did open when I mixed the brass or switched it into the other rifle, for what ever reason.

I now keep the brass in separate lots, for each rifle. Both of these rifles were chambered with the same Palma Match reamer. They both are loaded on the same die set at the same settings. It is impossible to tell from the fired brass which rifle shot it. The brass is all conentric on the run out gauge as well. Go figure.

 

[blargon]

Might be a dumb question but what difference does the weight of the brass make?

Consistency is the name of the accuracy game.

In theory, for the best accuracy everything should be identical. Bullets that weigh exactly what they should, cases with exactly the same capacity, exact powder charges...Of course its hard to have everything perfect and exact, but the closer you can get, the better off you are...

 

[rnbra-shooter]

Might be a dumb question but what difference does the weight of the brass make?

Heavier weight suggests smaller internal case volume.

Differences in case volume affect the maximum pressure achieved with a given charge. So trying to use cases with similar volume to each other is intended to reduce the variation in muzzle velocity from shot to shot.

 

[Mystic Precision]

Go with the 1F Win - reason, the more times a case gets fired, the more work hardened the necks become and this can lead to irratic bullet release.

Annealing is the solution but I am still trying to find a reliable, repeatable method that doesn't take all day to screw up

Check case volume NOT case weight. Take cases that are from the same lot that are at the extremes of your weigh range and check their volumes (fireformed first). I bet they are dead on.

Measure brass from different lots that weigh the same and I bet you will find more variation in case volume.

Inference takes alot of assumption and that just leads to a big waste of time.

You did trim, deburr, chamfer all your cases identically before weighing right?

This alone can throw your cases way off in weight. Then there is the machining difference in the extractor groove.

The best thing you can do to improve your 223 shooting is get a precise scale. A scale that is rated with an error UNDER 0.1gr TOTAL SPREAD.

I use the Jennings MACK20 and it works very well. Has made a huge improvement in my LR consistency with my 223 rifles.

I am guessing you will feed the barrel Amax or Bergers? Varget, CCI 450 primers and good dies and you will have lots of fun plinking beyond 1000yds.

Enjoy...

Jerry

 

[warrenb]

Go with the 1F Win - reason, the more times a case gets fired, the more work hardened the necks become and this can lead to irratic bullet release.Jerry

Now you tell me. I've just prepped 150 ###.

Jerry, I've read your article describing selecting match brass a few times in the past. I thought I had read that the brass did not have to be from the same lot. Did I get that wrong?
This is once fired brass that I collect after the LEOs have been shooting at the range.
I was intending to scrap the brass that did not fall into the same group (5 fired shots) twice, similar to how you describe in your article.

Can you elaborate on your preference for the 1F Win over the 1F Rem. Is it because the Rem brass work hardens quicker. Or did you mean pick the win over the 6F rem? I have had good results annealing the Rem brass previously btw.

Yes I did did trim, deburr, chamfer all cases before weighing. The weight range I gave were the 2 extremes.

Thanks for all the responses so far guys. I learn more every time I read this forum and the advice is very much appreciated.

 

[Mystic Precision]

Either brand can work just fine. I thought you said the Rem was multi fired and needed to be resized? Always best to work with brass as new as possible.

If you can anneal well, you have conquered a huge part of the brass consistency equation. Love to hear your technique.

The LEO stuff is just fine cause it likely came from the same lot of ammo.

As with any product manf, changes in materials, tolerances and tooling will vary the end results. For most things, it just doesn't matter but if you are trying to squeeze the best accuracy possible, small things do add up.

Jerry