Having recently taken home a suitable weighing instrument, and the weather not being fit to do anything outdoors, I sat down with a 100 or so Federal .22/250 cases the other night and whata range of weights. These are ready primed for reloading and have been shot 2 or 3 times already but the weights ranged noticeably.

I sorted them to the nearest whole grain and got these readings: 161, 163, 164, 168, 169, 170, 171, 172, 173 grains. By far the vast majority weighed in at 170, 171 or 172gn and in some cases only 1 or 2 cases registering in the other weights - these I re-weighed to be sure.

In terms of which represent the best to use, I'm open to correction but at this stage, my assumptions are:
1. All have been fired in my rifle and I can therefore assume they've all got the same overall dimensions. Therefore,
2. The heavier cases must be thicker at some point and that this increased thicknesss reduces internal dimensions. Therefore,
3. The heavier cases have less internal space for detonation/powder burn and could give a higher velocity at the muzzle, though whether this will be measurable, only time with the chrono will tell.
4. Overall, the benefit of sorting cases by weight is going to show up in shot by shot consistency.

Comments guys?

You've arrived at the precise reason those striving for benchrest accuracy and consistency sort cases by weight.

Yep, Bob nailed it on the head. I ALWAYS weight sort my cases BEFORE the first firing, thereby eliminating any "bad" ones right away.
My method is to weigh ten cases and get an average, then from there anything that is over 1% under/above that number is thrown out.
I use the thrown out ones for fouling shots or offhand practice, reserving the good ones for serious hunting/target work.

This doesn't mean that the heavier cases aren't usable. They just need to be used with a different load. Settle on a range of values to be included in a single lot, then assign lot numbers to each lot (weight range). When you work up a load, load by lot.
Personally, I use fingernail polish of different colors to designate which cases belong to which lot. Makes a good primer sealer, too.
Regards,
'puck

WELL--JUST TO THROW A MONKEY WRENCH IN HERE!!! I've read over and over how heavier cases hold less powder. Then I took a couple cases in 30-06 that had a weight difference of 12 grains and filled them with water and guess what???--they both held 67.5 grains of water!!

I'm getting kind of tired of all this exacting hype. I'M NOT A BENCHREST SHOOTER, and I don't think it makes that much difference anymore.
Yes, I'll set my dies for minimum runnout and minimum shoulderspace and I'll try and get repeatable neck tension-----after that..........
good luck to the bullet going down 24" of barrel!!

I think you nailed it, kraky. I just wish I could stop

R-WEST

Hey Pete, I do a full Case Prep routine and then Weight Sort my rifle cases too. I do not weight sort with primers in the pockets since they could potentially skew the results slightly.

Even go so far as to stick a piece of Scotch Magic Transparent Tape on each case to record the exact weight on it. And keep a Statistics Sheet to monitor the results. (If anyone else goes to this trouble, it is important to use this tape so as not to leave glue residue on the case when you eventually remove it.)

I think of it as "Blue Printing" the cases. In my mind it is similar to Blue Printing an engine to get the best possible balance and performance.

But, the most important thing I get from going through all this stuff is "confidence" in the final hunting loads. I know I've done everything I consider essential to making sure each cartridge is as close to the same as the next one. And that gives me the level of confidence I want.

Now having said all that, I can see how Kraky got his results and why he is happy with random picked cases. No argument at all from me. I agree the results of some things I do to my cases are dubious at best.

It does take a whole lot of time to do 300-500 cases, but I only have to do it "once".