weight sorting

[chet]

Typically I do not weight sort, mostly because I buy and keep my rifle brass in lots. Therefore i feel it unnecesary.
However!!!---- I just finished prepping my 325 brass, and figured I'd weigh it all, just to see how it'd fair. It is all winchester brass.
Now, keep in mind this brass is from at least 3 different lots. 40 of them came from 2 boxes of winchester factory ammo, each from a different lot. And the other 45 came from a fellow forum member. So who knows how many lots I've intermingled :lol: at least three 8)

Prep: Full-length sized, trimmed, chamfered, de-burred, uniformed, and neck-turned.

I did everything I possibly could to ensure that all 85 pieces are externally identical. Weighing them will inform me of any internal differences. I was impressed with how close they all are.

Average weight: 227.3 grains
three lightest: 225.6, 225.9, 225.9
two heaviest: 229.9, 230.2

Before i started, I figured anything within 1% of average would be a keeper, and I'd "mark" the rest for foulers, set-up dummies, etc...... well, only the two heavy ones are out of range. I inspected them carefully, trying to find the extra weight. Can't find it :roll: I colored them with a marker, and threw them all in the same bag. After I find my load, I'll shoot the heavy ones to see if there is any noticable increase in velocity--- I doubt I'll see any difference.

In the end, it was an educational 30 minutes, And a whole lot better than watching the disney channel with the kids :lol:

 

[SJB358]

Wow, I have never done that before. I hear it pays off to some extent, but that was a great post. Seems like WW is keeping their brass in decent spec. Scotty

 

[chet]

I only did it because I was aware of the multiple lots, and I expected a much higher deviation. I think it speaks highly of Winchesters brass. I just ordered a concentricity guage, I'm being real picky with this rifles loads. I hope the new guage doesn't humble me too much

 

[DrMike]

Fascinating. It does lend confidence.

 

[backcountryhunter]

Most of us have found that the WSM factory brass is very uniform and darn tough - I would bet that part of that is because WW wanted these WSM cartridges and the rifles to sell well so they have taken extra pains - I encountered a sizing challenge with the 325 nickel plated 1x fired, be sure to lube the inside of the necks with imperial wax or the like (you can wipe it out with a Q-tip after) I actually moved the shoulder forward slightly but enough to cause chambering issues big time - I do like these WSM's !!

 

[chet]

ditto on the neck lube, bch.

 

[negeorgia]

For comparison, 57 new RP cases for the 6.5mm Rem Mag:

Median weight 215.7 grains, and there were 7 at that weight.

21 pieces in the range 215.5 to 215.9.

16 pieces between 215.4 and 213.1 (lightest).

20 pieces between 216.0 and 217.9 (heaviest).

46 out of 57 (80%) are within a 1% spread.

19% are not inside 1%.

 

[BK]

Wow, you guys are going to force me in to buying a digital scale, aren't you?

I would be more concerned with my .17 Remington, .204 Ruger, .221 Fireball (particularly), and .223 than my WSM, H&H, and '06 based cases.

 

[Desert Fox]

Sorting brass by weight helps eliminate occasional flyer. I always sort my brass by weight. No more than 1 grain on a 30-06/308 size case. 1.5 for the big magnum cases and .5 grain for the 223 class of cartridges.
We took pains in weighing powder, uniforming primer pocket, trim the case to uniform length and weigh bullet, but then neglect one of the most important process in reloading in my opinion, which is weighing cases. I see this time after time at the shooting range. Guys will have two shot touching and then one is thrown out of the group. We all experienced this. We usually look at other things to blame. Remember, reloading is about consistency. A case that weigh more have less volume than the case that weigh less. If you load both case with the same amount of powder, and all else being equal, the case with less volume will have more resultant pressure and probably will peak much sooner. Guess what will this do to your barrel harmonics.
Just to prove my point about barrel harmonics. You guys probably have seen the picture of the 10 shot group I shot with my 308 that I posted here on several occasion. I made these 10 cartridge as uniformed as I can make them. The only difference is about half a grain of powder. 5 were loaded with 43 grains of BLC-2, the other 5 were loaded with 43.5 grain. I have one flyer... shooters fault not the rifle. As you can see one group was just slightly above another. This clearly shows that half grain difference in powder charged made a change in pressure which in turn affect barrel harmonics. This in turn change the point of impact also.

 

[atmoshpere]

Chet,

I'm glad that you mentioned that you do everything you can to make the outside of the case identical before you weight sort them. This is something i've always been confused about. I've read quite a few posts on various forums where people were weight sorting their brass before they'd done anything to uniform their exterior dimensions. This didn't make any sense to me. I thought that the purpose of weight sorting was to measure variance in internal case volume (which as you and desert fox mentioned, leads to pressure variance that can change poi). It seemed to me that the only way that internal case volume variance could be quantified by weight, was if the outer dimensions of each case were the same.

I'd sure be interested to see what results you get from shooting your different weights of cases. Do you think it will have much difference at average hunting ranges, or is the benefit negligible unless you're shooting 1k comps?

 

[chet]

Atmosphere, this weekend I'll be performing a test.
I'll shoot my 308, three shots. Using the three lightest cases from my batch.
This gun shoots 1/2" groups when I do my part.
I then will shoot the heaviest case from my batch. Hopefully it'll be heavy enough to make the test worth tryin.
I will take note of velocity and POI.
My only concern is when to fire the heavy case..... first? last? somewhere in the middle?

 

[atmoshpere]

If you can shoot 5 shot groups without a poi shift from heating, then I would say you could shoot your heavy "test" case in the middle of your 3-shot group. Ultimately I would think for a true experiment that you'd want all barrel/chamber conditions (temp) to be as consistent as possible for each shot, but that would require letting the barrel cool completely between shots, which may not be becessary in your rifle anyways. Of course the chrony data may be more valuable than impact data at 100 yds anyways as it will probably be a better indicator of pressure changes, which is what we're trying to measure in the first place right? :mrgreen:

Keep us posted!

 

[chet]

agreed!

although a cartridge with more case capacity may give us more results.....
hmmmm maybe I'll try the 300 winny also - - except it does start to wander a bit with barrel heat.
hey, whatever excuse i need to shoot more, right? :lol:

 

[atmoshpere]

hey, whatever excuse i need to shoot more, right? :lol:

Exactly! I'm thinking about all of the things I wanna play with while developing a load for my rifle I'm getting ready to build and let's just say I keep finding new things to "wonder" about. :grin: