Sizing consistency after annealing

[Ekupp]

Need more info!

This is what a lot of us see. You don't need to anneal brass longer. In a group of brass, some are just stubborn. You bump them shoulders .002 from fired size and the ones that don't go along with the program, you save for the last and screw your sizing die in a bit and size them the same too. This happens to all of us.

Gingerman: I agree, the ones that have me scratching my head are the ones that come in undersized. They can be set aside and loaded as foulers and will fireform back to normal size. Incrementally annealling longer in controlled .1s gets rid of the stubborn ones, mostly.

My goal in annealing is more for consistent sizing, if that is not the case then I will revert to annealing every 2-3 firings.

 

[Ekupp]

Just to clarify your "target", are you measuring neck ID, case overall length, headspace (shoulder bump), or something else after annealing and re-sizing?

Cartridge Base To Shoulder is the dimension I am looking to get consistent sizing without too much hassle.

 

[Ekupp]

Ekupp, Perhaps the brass is not being annealed after the same number of firings?

In this case all brass was 2x

 

[DoneNOut]

@Ekupp - Sometimes the composition of brass is beyond our control. So, we gotta adapt to it!

 

[R.Morehouse]

I leave the brass up in the die while I ready another piece for sizing. Usually 10+ seconds, I tell myself this helps with spring back......

Regards
Rick

 

[emp1953]

Mine were certainly the same number of firings and none of that brass had ever been shot to pressure. I've been running that gun slow.

Interestingly, I found internal doughnuts on that brass after five shots, too.

Where in the case were the internal donuts observed? I'm curious now.

 

[victor3ranger]

These donuts everyone speaks about, does anyone have a picture of this?

 

[parshal]

There are quite a few pics of them on the Internet. They are right at the neck/shoulder junction. If you slide a pin gauge that just fits the ID of the neck you will hit a hard stop as you slide it down the neck.

I don't want to derail this thread talking about doughnuts, though. It was just something that I thought odd on Lapua brass with such low round count. I figure that's part of the tougher to resize issue on the PRC even after annealing.

 

[PddPdd]

Cartridge Base To Shoulder is the dimension I am looking to get consistent sizing without too much hassle.

My personal solution for consistent shoulder bump is to anneal before re-sizing every time. I also will run the brass into the re-sizing die 3-4 times with a ~60 degree rotation between each handle swing of the press if a case is being stubborn. For some cases the multiple handle swing is standard operating procedure. I always check the empty, resized case in the action of the rifle before proceeding with reloading.

 

[C-130 Dude]

My primary goal in annealing is to get consistent full length sizing. What I have noticed with certain sets of brass is that after annealing 70% of cases will be +/- .0005" of my target. 15% will be stubborn and not size and 15% will under size by .002-.004.

As an experiment I kept annealing the stubborn pieces for .1s longer till I got them to the proper size.

So, am I not annealing long enough or am I annealing too long and starting to get 15% that are too relaxed with the stubborn ones just needing to get adjusted to the baseline of the batch?

There are quite a few videos on proper annealing on YT. Be very careful not to over do it. You don't want the brass to get to soft. Pay attention to how far down the heat streak goes. See videos on this. If you want, you could use Templac. When you size your brass, pause at the bottom of the press stroke (3-5 secs). This allows the brass to setup to your required size. Will reduce spring back. I shoot for 2-3 thousands. BTW, if you really want optimum control on your annealing, get an AMP. Pricy, yes. But they work.

 

[Okanogan]

I've been having a similar issue with my 6.5 SAUM cases and ADG brass using Redding Competition neck bushing die. I have the ability to anneal with an Anne set up but instead of trying annealing as a first solution I switched to Short Action Customs modular die ($$). The die has essentially a bushing that resizes both the neck and shoulder bump together. Hopefully it will at a minimum get rid of the potential for internal doughnuts.

Part of my motivation for the switch was a recent article in Precision Rifle Blog that covered the reloading practices of one of the top shooters in detail. He annealed each time and used the SAC dies. I haven't gotten far enough with the SAC die use yet to confirm whether it will solve the issues I was having.

 

[JustMe2]

My personal solution for consistent shoulder bump is to anneal before re-sizing every time. I also will run the brass into the re-sizing die 3-4 times with a ~60 degree rotation between each handle swing of the press if a case is being stubborn. For some cases the multiple handle swing is standard operating procedure. I always check the empty, resized case in the action of the rifle before proceeding with reloading.

Pdd, I'm not sure this is a good practice. You anneal to soften the brass and then you resize it 3-4 times which hardens your brass defeating your annealing. Every time you resize, you harden your brass, it does not require firing to harden brass. I feel you are over working your brass and reducing its lifespan.

 

[emp1953]

There are quite a few pics of them on the Internet. They are right at the neck/shoulder junction. If you slide a pin gauge that just fits the ID of the neck you will hit a hard stop as you slide it down the neck.

I don't want to derail this thread talking about doughnuts, though. It was just something that I thought odd on Lapua brass with such low round count. I figure that's part of the tougher to resize issue on the PRC even after annealing.

I've been looking online at some pictures and explanations. It seems to be most prevalent on cases that are necked up. Is it common to occur on cases that are just full-length sized to the same caliber? The existence of these donuts could explain inconsistent groups with previously proven accurate loads. Another part of my case inspection and a few more tools I guess. Upon further thought, this could cause a number of anomalies with previously perfectly performing loads.

 

[PddPdd]

Pdd, I'm not sure this is a good practice. You anneal to soften the brass and then you resize it 3-4 times which hardens your brass defeating your annealing. Every time you resize, you harden your brass, it does not require firing to harden brass. I feel you are over working your brass and reducing its lifespan.

JustMe2,

I sincerely appreciate your concern.

The engineers who designed the AMP annealer, which I use, have shown in hardness testing that as long as you keep the annealing settings (time & heat) the same, repeat annealing does not change the brass hardness or grain structure of the brass.

Here is the video showing this:

The reason for annealing is to get an accurate, consistent hardness baseline for resizing with the same amount of work hardening occurring on every piece of brass when you re-size it.

The repeated working of the press is similar to holding the brass in the sizing die longer to get that last .0005" to .001" of sizing needed to bump the shoulder for smooth bolt operation. Brass hardening occurs when you deform it. The more you deform it past it's elastic limit, the more work hardening you induce.