1) I have a batch of Lapua brass in 30.06 that I have necked down for 270. This brass is shorter than standard 270 brass, and here lies the question: Even after firing, and neck sizing, this brass is 2.48. Trim length of standard 270 brass is 2.53. Will this length difference cause fouling to build up over time, and what if I decide to go back to some other brass in standard 270 and trim it to 2.53? Any problems with this?

2) Just how important is weight sorting brass? I weighed roughly 500 WW 270 brass and the weight varied from 183.5 to 191.7, all virgin brass. The bulk of it fell into 188.8, 189.2, and 191.5, so there was no problem getting plenty for a wt. sorted lot. But, lets say someone does not weight sort. Here's something I'm wondering about:

If I take 4 brass, all identical wt, trimmed, fully prepped and retest a known load that shoots well, and these identical brass reproduce it, what do you think would be the difference if everything remains the same except the brass? Say you use one at 183.5, one at 191.5, and 2 somewhere in between.

You think this may be an answer for some flyers? What do you think is really more important, wt. sorting brass, or near identical brass prep, such as neck turning and precision resizing?

Nosler Custom brass is wt. sorted. Serious bench shooters typically use Lapua brass when they can as it seems to be very tight with weight differences. Just how important is this for accuracy?

first off you are only looking at about a 4% diffrenc in the whole lot. the length is no problem as long as they are all the same. when you switch to a case with a longeer neck the bullet will be help by aproximately .006" ..longer neck may or may not increase bullet grip?
I have not weighed lapua brass for a while.
its only important if you are shooting one hole groups at 600 yrds with a benchrest rifle.
there are far many more variables that affect accuracy than case weight. I you take one case and fire it one after the other until that case fails you will see a diffrences in the case between the first and second firing and the last firing when the case fails. the only reason to turn neck would be if you had a tight or custom . or if the brass was thicker on one side compared to the other. and then only enough to true up the necks.
new brass I like to run it through a neck die and then trim to length load and shoot with a known load. while fire forming the brass I group the brass by where it impacts the target. with in a 1" group at 100yrs 3" group at 300yrs basically MOA. cases that are out side of moa go into left right groups. up and down is my fault and I do not consider that.
now how anal are you? I can go on and on.
Dave

The slightly short necks on the resized '06 brass are irrelavent to performance.

Weighing your brass is one way to check for defects. If a piece of brass varies from the norm by double the normal variation, then you probably want to set it aside. Otherwise, weight-sorting brass that is within 4% of norm will result in no measurable benefits.

quote:

Originally posted by Doc:
1)... Will this length difference cause fouling to build up over time,

Hey Doc, I had a buddy's nephew, Eddie, shoot a lot of 38Spls in a 357Mag. He cleaned it and it looked fine through the Chamber, but it would cause the 357Mags to Hang in place after firing. We discussed it and a serious cleaning was done on his Cylinder. It fixed his problem, but the 38Spl Case is a lot shorter. So, I doubt you would ever know it on a Bolt Action.

quote:

2) Just how important is weight sorting brass? ...

I Weight-Sort all my Cases, and I do occasionally find a few which are w-a-y outside the Norm. And of course there is a normal Bell Curve to the weight range. But before I start, I P-FLR the entire Lot and do a Full Case Prep on every Case.

I go so far as to put a piece of 3M Magic Tape on each case and write the weight on it. And I keep a Tally Sheet for the individual Weights. Then when I'm through, I can sort them into any size Lots I desire.

With a 500 Case-Lot purchase, you can end up with many separate Lots that all the Cases weigh the exact same amount (20-80).

I've no argument at all with people who do not weight-sort, but I do it to help buid confidence in the Final Load.

Also as "Hivel" mentioned, if I experience a Flier, I mark the Case and see if it does it on the 2nd shot. If it does, it is removed from that Lot and used for other things.

By the time the Cases are ready for the 3rd Shot, they are Fully Fire Formed and as close to being exactly alike as I can make them. These are the Cartridges that get to go Hunting with me and I have extremely high confidence in them "not" creating a problem.
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Don't know if Weight-Sorting helps a lot or not, but I do it, because it is my time to use as I see fit.

Good Hunting and clean 1-shot Kills.

quote:

Originally posted by hivelosity:
first off you are only looking at about a 4% diffrenc in the whole lot.

Right. But, seems like I read somewhere that 7-10 grains difference in brass wt. is roughly the same as a grain difference in powder charge. True? I don't know.

quote:

I have not weighed lapua brass for a while.

I don't think it is necessary, IME anyway. One more reason Lapua is so popular, so long as you buy the same lot.

quote:

the only reason to turn neck would be if you had a tight or custom . or if the brass was thicker on one side compared to the other.

I have yet to find any "true necked" brass. Even lapua has varied. Most all brass I've encountered has a thick sided neck. Maybe not much on some, but for the most part, bottleneck brass is asymmetric.

quote:

now how anal are you? I can go on and on. Dave

Well, I have been called A$$hole before, I guess that makes me anal from outside in?

maybe the grain diffrence is not applicable with volume which is what you are trying to accomplish by weighing. all the weight does is tell you one piece of brass is diffrent from another by weight.
It could be in the length of the case if they are not exactly the same.
It could be in the base or for that in the size or thickness of the rim, 4% hant nothin..
"" have yet to find any "true necked" brass. Even lapua has varied. Most all brass I've encountered has a thick sided neck. Maybe not much on some, but for the most part, bottleneck brass is asymmetric.""
the idea here is to have the bullet centered as close as possible to the center line of the case and chamber. the idea is if the bullet and case are streight with the bore then the bullet will start down the barrel streight, in turn will produce a more accurate group.
have yet to find any "true necked" brass
Just how close do the numbers have to be?
I repair machines with tolerances to with 1/100ths of a milimeter. have you ever looked at 1/100 of a milimeter. you breath on it and it changes.
I checked some lapua 243 brass a while ago and total weight varried by 5grains thats
(+-).15grains there are 7000 of them in a pound.
neck thickness was measured in four places from.014" to .0155" thats .0015" total and (+-)
.00075" if I do any thing to this brass I will screw it up.
MY POINT IS THEY ARE ONLY NUMBERS DONT GET HUNG UP ON THE.. YOU CAN WAY OVER THINK THIS.

If you feel the need to sort brass, sort it by capacity.

what is the preferred method of sorting by capacity?

Hot Core, why don't you just write the weight on the side with a magic marker?

quote:

Originally posted by stillbeeman:
Hot Core, why don't you just write the weight on the side with a magic marker?

I'm concerned that I might buy some kind of "Marker" that has Ammonia in it. I could get an MSDS sheet from the manufacturer, but formulas change. Plus, if you handle the Cases a good bit, it will rub off quite easily and then you have to re-weigh.

By the way, I tried regular old Masking Tape at one time . Talk about a mess of Tape Residue left on the cases - pitiful.

The 3M Magic Transparent Tape can be removed and leaves no residue. And the Ball Point Pen Ink stays on the Tape. Other Tapes might work as well, but I've not tried them.

Similar to Reaming Flash Holes, it only has to be done "one time". I do find it a major advantage to do Case Weighing with an electronic scale, even though they are tricky if any slight air movement(wind, air conditioner, fan, furnace, arm movement, etc.) causes them to "search" for the correct weight.
-----

But, I still do not claim weight sorting is necessary - it is just what I do.

From a theoritical point, the Cases should "ALL" be fully Prepped and Fired Twice at near full Loads before sorting by Internal Water Volume so that all the External Dimensions of the Cases fully fit the Chamber. Then a question arises about the Spent Primers being slightly different in weight, any variance in Residue, height of the Water being exactly even at the top of the Case Mouth. All of that seems to be waaaaaaaaaaaay to much thinking on the subject.

So, I Weight Sort by Case Weight and do as HiVel mentioned about looking for Cases that cause Fliers.

Might be a total waste of time. But...., I like to shoot against folks that don't do it.

quote:

what is the preferred method of sorting by capacity?

Fill the case, after resizing, with distilled water and then weigh the water.

I once tried the water method and only thing that turned out was a mess for me.
Doc, here is some of that anal thinking.
so I contrived another method when done i realized that If i had looked in a sierra reloading manual i would have had the load density for that cartrage.
22/250 rem. winchester brass will hold 44.2grs, level to the top of the case, of H414 with a max load of 41grs with a with a diffrence of 3.2grs ... about 92% load density.

I'm not going to go through the trouble of using water to sort by capacity. If I was a benchrest competitor, maybe. I've been 98% happy with my hunting loads the last 10 years, but I'm still learning.

I sorted my brass by weight, and in any one batch, there is no more than 0.3 grains difference, plus there are plenty of hulls per batch.

You folks have got a looooooot of time on your hands.

Why not fill each case up to the top with H414, tap it once on a table, top it up if needed, strike it off even with the mouth of the case, and then weight the entire case on an electronic scale. Or pour the charge out and weigh it. Lots less messy IMO. I daresay that H414 would lie evenly enough in the case to be consistant. Or is that not complicated enough?

I don't think you will have trouble with the brass being slightly short. Many reloaders use brass of a diff headstamp for certain carts and I've never heard a complaint. My main concern would be the lengths after a few firings. Even thought the need for trimming due to excessive length is probably not going to be a problem in this instance, it would probably be wise to be sure that your brass is the same length after a couple of firings.

In my paper punchers, I weight sort brass and try to stay within 1 grn, but quite honestly, I feel it's alot like a dog chasing his tail...

I have mixed a few varying weights in on one of my rigs(The only rifle I own that regularly shoots in the .1s) and it never really seemed to matter.

Good Luck

Reloader