Reloading Question

[TonyM]

A tiny bit of bullet setback can raise internal case pressures significantly (and in a nonlinear fashion) into dangerous territory...

Very true, especially with 40S&W, the pressures in that caliber are very high, and increase at a fast rate when OAL shrinks.

[-hanko]

I might be more worried about vibrations somehow causing bullet setback in cases.

If setback is an issue in a vibratory case cleaner, I'd definitely be concerned about setback after recoil in a pistol magazine. Sounds like the ammo may need a little more crimp

-hanko

[Python]

Tumble loaded rounds ?

I'll support the other side. I tumble almost all my ammo after loading, and even my .223 and .308 ammo I buy.

For reloads I do it to remove any Hornady case lube that is on them, after it dries it feels sticky, and I don't want that in my mags or chambers.

For my .223 and .308 Military production ammo I do it to clean up the ammo from brown to nice and clean. The Belgian and Aussie .308 comes out looking like factory ammo. I know I don't need to, but I prefer clean ammo in my weapons and have convinced myself that it will keep the gun cleaner, even if it wont.

I usually tumble for 20 minutes in 50% walnut, 50% corncob with some polish, but I have tumbled some overnight on accident w/o any change in the powder or accuracy. I even pulled some bullets to look at the powder from tumbled and non tumbled rounds. under a scope they looked the same.

Reading on a few forums it has been said that the only powders that could hurt would be powders from well before the 1970s.

Could you send me info on other forums' web addresses ? Thanks, Python

[Yar]

If what you want is a shiny case that looks factory new what you need is to do a better job with the first initial tumbling and use clean reloading dies.

I use all walnut media and 3m Finesse it II compound. It works better than the Blue Dillion stuff. It makes your brass super bling with less tumbling. Also there is a trick to tumbling. You got to tumble the right amount of brass, not too much and not too little. I run the tumbler empty with no brass and add brass in a handful at a time until I see the brass moving pretty fast. Like it makes a rotation in one second from top to bottom. Change your media often too. I get a 25lbs bag of walnut media of $10 at the local animal feed store. They called it bird litter. Mix 2 parts finness it II compound with water and add it to the media while it is moving in a tumbler without cases. Wait till it distrubutes and de-clumps.

Also make sure your dies are clean. Dirty dies leave a black grease ring on the case when your loading them. Clean your dies regularly with solvant. While case lube feels sticky (I use one shot) it doesn't interfer with feeding in the pistol. If your worried about it "mist" (not soak) a cotton towel with carb cleaner and then roll your loaded ammo around in the towel for a few seconds.

As far as tumbling loaded cases it is fine if you don't tumble too many, and only tumble for 20 minutes.