.015 Variance in 9mm COAL

[IVC]

1 hour ago, ddc said:

In a perfect, theoretical world where every manufacturer uses the same brass formulation and the same wall thickness and every piece of brass from these different manufacturers is exactly the same from one producer to the next? Then there would no effect on OAL... but that is not the real world.

Brass can be completely different, not even the same caliber. If the press completes the cycle, the distance between the seating stem and the base of the shellplate will be the same, so we get the same OAL. Or, if I reverse the statement, if the OAL is different, there is movement of the bullet that is unrelated to the seating process, which is a bug in the setup. 

[Joe4d]

As mentioned smooth even strokes all the way down pause all the way up  , slight push forward to fully seat the primer, rotate a fairly tight shellholder to QC primer depth

 

[Dr. Phil]

The way I see it, for the 10 minutes it might take to sort out 10 each of 4 or 5 headstamps, load and measure, it is worth the time. If nothing else, you wind up with 50 loaded rounds.

Then you might actually know.

I have sorted FC for my revolvers because some of the others don't fit my moon clips properly. The manufacturers are all different. From primer pockets to web to case thickness. And it does make a difference.

My autos use range brass because that .015 is not actually noteworthy for a gun and load that at best might be 2" at 25 yards. Most are not that good for many shooters. Most of that type of shooting is closer. If it were a PPC or NRA gun and load, yeah maybe.

Hard to believe folks would rather argue than test.

But the load development was a big factor that got me into reloading in the first place.

Not so much now I guess.

[shred]

Compressed powder charges will grow a little depending on how fast you cycle the press, but I don't think the OP is loading compressed loads.

 

[IVC]

On 8/19/2023 at 6:42 AM, Dr. Phil said:

I have sorted FC for my revolvers because some of the others don't fit my moon clips properly. The manufacturers are all different. From primer pockets to web to case thickness. And it does make a difference.

Of course it does make a difference in some aspects of reloading, but not all.

 

For example, a powder drop will drop the same amount of powder regardless of variances in brass, right? That's because how it's designed and how it works. The question about OAL and the seating die is a valid question - does it depend on the type of brass or not? If it does, there must be an accompanying explanation how the fixed distance between the shell plate and the seating stem changes the OAL based on the case properties. 

[DougCarden]

It is the variance of the brass.  Unless you are shooting at 50 yards then don't sweat it.  If you are shooting at 50 yards then-  rollsize, sort brass and use same headstamp, make a custom stem for your seating stem so it fits your bullet perfectly and seats it the same each time, time your down stroke the same for powder drop consistency.  These are things that will help in accuracy because consistency matters with ammo.