Brass Sizing Dwell Time

[FredHammer]

New one for me. Watched a video of a guy talking brass prep. (It wasn’t that shoulder bumping or lack thereof video)

Guy was talking dwell time in the die for sizing. Something like up to 6-7 seconds you should leave each piece in the die because the properties in brass need time to flow.

25yrs hand loading and this pops up for me. What do you all think?

 

[Ryridesmotox]

I don't go fast, but I'm not waiting 7 seconds either.

I anneal every firing now and I have been getting sizing the same across all cases to +/-.0005 at the datum, and that's using a Full Length Lee die. I might give it a second or 2. But usually I just do a slow deliberate stroke... which is the exact opposite of how I handle other things

I've heard the same thing though, and I wonder if it's from people that don't anneal, or don't anneal enough.

 

[FredHammer]

Welp, that would certainly apply to me then. I load Lapua mostly and its annealed for the first firing, but not the following. I'm still ringing steel the way I like.

 

[supercorndogs]

You probably heard it from people who measure their brass, and found if they didn't pause for a couple seconds at the top the stroke. Their shoulder bump was not consistent. Not pausing often leads to some cases that are hard to chamber if you are running .001-.003 shoulder bump.

 

[Bigwheels]

In my experience it not only effects the shoulder but the necks as well. I leave them in for a 5 count & my seating pressure is more consistent.

 

[supercorndogs]

A reloader on here, I trust, suggested pausing on the expander ball also. For those still using standard FL dies.

 

[E. Bryant]

There is absolutely no time dependency on the flow of metal under these conditions. What does matter is having a smooth, repeatable stroke of the reloading press, and slowing down probably helps some people be more consistent.

 

[Ryridesmotox]

A reloader on here, I trust, suggested pausing on the expander ball also. For those still using standard FL dies.

On which part of the neck though? I'm always down to try something different. I've always heard that a slow consistent pace, with a brief pause at the top of the ram stroke yields the best result. Seems like the expander ball pausing may lead to a bulge in one spot? Or maybe not a bulge, but a difference in how that particular spot was sized. I could see if your expander button has a longer cylindrical shape, where you could pause, and allow the neck to be made into a uniform size all at once. But most of the expander I see are too short to do that. I'm no expert though,

 

[anotherwannabe]

I used to just pop them down and up like most people. I anneal every time. Read about dwell time and figured testing and measuring 25 with additional dwell versus not was an easy test. For me the results were absolutely conclusive it makes the shoulder setback more consistent.

Does it matter (in your or anyone else’s case)? Maybe not, but I don’t think anyone who has done the experiment will claim it doesn’t improve consistency.

 

[Supersubes]

I think there’s some meaningful gains to being a little saavy with the press. I hold at the bottom of the stroke for 1-2 seconds, which makes for consistent bump. I also don’t just cram the case into the die, I raise the ram till the case touches the die, back off slightly, then slow and smooth through the full stroke. I do this to ensure things are centered. I do the same coming out over the expander ball.

 

[FLIGHT762]

I do the same thing. ^^^^^^^^^^. 2 second pause in the die. It does give a more consistent sizing.