when to anneal.
- Thread starter philkelly
- Start date
When annealing, especially induction annealing, it will leave a scale on the inside of the case neck. You can't wash it off.
Hence why they recommend annealing, then lubing and sizing; the expander button (or mandrel) scrapes the scale from the inside of the neck.
Malxwal
Well-Known Member
It doesn't clean off with wet steel pin tumbling ?
I size with bushing dies, and not every cartridge then requires mandrel sizing (some work better than others with more neck tension).
Stalker62
Well-Known Member
I should have been more clear. For precision cases wet tumbling with media is bad; it peens the case necks over time. You can get y doing it for 3-5 cleanings, but eventually the neck walls become uneven due to the peeing. I was suspicious of this statement initially myself. But, after several tumblings with SS media, I noticed accuracy was falling off at distance (unexplained flyers, typically vertically). On a hunch I broke out a neck turning tool and turn the necks on 5-10 cases. Everyone of them showed a peen neck, that extended down the case neck about 20-25%. In some cases it showed a peen case mouth, and a raised area in the middle of the case neck as well. These were cases that had been checked when new, and did not have excessively variable case neck wall thickness (when turned the cases showed a couple areas in the neck that were shallower than the cutter, but the cutter removed brass across the entire length of the neck, with a couple low spots here and there).
Now here's the weird thing. Even when the cases developed peened case necks, the accuracy at close range (say out to 500yds), there was very little evidence of it effecting accuracy. But at 850+yds it was clearly evident that something was amiss. When I switched to virgin brass, but with the same load, same rifle/barrel, the flyers at distance went away. I no longer wet tumble with SS media every time I clean the cases, and only do it when the cases will not come clean with just straight water/lemishine/soap.
What I meant was wet tumbling without ss media will not remove the scale, and there is a lot of debate whether it removes even with SS media, since the pins are just rolling around inside the neck, and not getting punched into the inside case neck, like the outside does. The scale has been developed (as I understand it) from the heat of annealing oxidizing on the brass. Meaning it is chemically bonded to the brass, so a simple wash will not remove it. Much like when welding, the scale needs to be broken off the material.
As to sizing with a bushing die, IMHO it doesn't matter if its a bushing die or a FL die, all cases should be sized to the point where an expander mandrel or expander button makes contact with the inside of the case neck on ALL cases. This is so that there is no variability in neck tension. I would humbly recommend you go down a size in bushing if all your case necks are not getting set back enough to require a pass with a mandrel. Uniformity is king in case prep.
Finally, let me again preface all of this as being applicable to precision reloading for long range use. A stalker at typical hunting distances will not see differences that will affect accuracy at those ranges.
JMTCW....
LOL! I stand corrected. From where I am, they're both about the same distance away.
Probably got them confused with the Rollsizer company location (which is Oz).
Stalker62
Well-Known Member
@MarinePMI
I just think it is important to get folks nationalities correct.
Failure to do so, can be seen as a combination of ignorance, incivility or just bad manners.
It is (forgive me for saying so), typical of you Canadians...
It's a joke!
LOL! Great, I just spit tea all over my keyboard. <chuckle> Thanks for the laugh, I needed it this morning.@MarinePMI
I just think it is important to get folks nationalities correct.
Failure to do so, can be seen as a combination of ignorance, incivility or just bad manners.
View attachment 441094
It is (forgive me for saying so), typical of you Canadians...
It's a joke!
Malxwal
Well-Known Member
Many thanks for the concise explanation, something to consider.
When I said some cases, I really meant some cartridge/chambering, for instance, my 300prc likes a good amount of neck tension which I could not achieve with available mandrel, so rely on just the bushing.
I would think perhaps a quick run over a copper bristle bore brush would serve to clean out that scale ?
When I said some cases, I really meant some cartridge/chambering, for instance, my 300prc likes a good amount of neck tension which I could not achieve with available mandrel, so rely on just the bushing.
I would think perhaps a quick run over a copper bristle bore brush would serve to clean out that scale ?
A copper or steel bristle brush would certainly work in my mind. Better yet, one set up in a die of some sort. Hmmm...maybe a Lee Universal flaring die with an insert threaded for a bore brush (8-32 IIRC)? Now that would be an interesting project...
Could even set one up with a nylon bristle brush with graphite to lube the inside neck for even more consistent neck tension.
A lot of guys are using Neolube #2 (liquid colloidal graphite) for inside neck lubing. Maybe make a weep hole in the die insert to periodically squirt the lube onto the nylon brush? Guys doing this are seeing SD's drop below 5fps.Squirrel cage is turning....
BTW, 21stCentury sells mandrels in .0005" increments.
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