Brass processing in advance

[Mike TackleBerry]

Maybe it makes a difference if you have a rifle that can shoot in the 1's. That eliminates 99.9% of us.

Not necessarily, Loaded ammo over time can allow humidity to migrate into the powder. Leaving powder in sealed containers and using humidity control in your reloading room makes a huge difference, I keep my Reloading room around 45%. I've noticed muzzle velocity disparity of 30 fps from ammo that was loaded 3 weeks prior to ammo loaded on the day of, When shooting 2500 yards that makes an astronomical difference in vertical stringing.

 

[jrb06]

So simple thinking here as I don't know the answer but wouldn't the overall spring back be the same regardless of the amount of time the cartridge sits? I understand measurements have been proven it changes size over time but with so many variables there is no one size or time frame fits all. At some point it will stop moving unless some additional force is applied to it in some way. So if this were to be true, unless you are loading at the bench and know how much spring back happens in that time and before the spring back can fully happen and you immediately fire it it it may be hard to determine if it is really changing ES.

Has anyone ever tested to see if the total spring back or final size changes after seating a bullet? As an example:
After sizing and waiting 4 days the measurement is XYZ
Seat a bullet and re-measure.
Seat a bullet in a case immediately after sizing check measurement.
Wait four days and re-measure.
What are the final comparisons?

I understand this all about having consistence so if you can determine when this spring back stops or is at the optimum point you should be abler to account for it when loading.

 

[Rick300]

To add to the above - I wonder if there a difference in springback of stopping at the top for 5 or 6 seconds vs just running them through?
I prep my brass in advance and haven't noticed any issues. I would think that with the close tolerances in a benchrest gun, I would get a round occasionally that would be hard to chamber. I don't seem to have that problem.

 

[dthomas]

I always prep my brass ahead of time, even for my f class rifles. I have not tested it against doing it all at once though.

 

[60723]

Probably not measurable but cases do spring back over just a few minutes. When turning necks if you don’t turn immediately after the expander mandrel, the case will fit too tight on the turning mandrel. Can’t expand 3-4 and then turn.

 

[RabbitSlayer]

Id try to load it all in one day if i didn't do batches of 250 or 500

 

[Ruger15151]

Thousands of pre-prepped cases with no issue. I do however anneal with an Amp every firing and also use an expander mandrel just before loading.

I understand you expand the necks just prior to reloading. However, do you prime you brass in advance as well?

I am just wondering if expanding a primed case changes the seating depth of the primer.