Sizing issues. Ugh!

Michael

Active Member. Uh/What
I made up a batch of Lee 338-220-R bullets out of COWW + 5% lino a little over 2 years ago before I started PC-ing, then about 6 months later I coated them. Now when trying to size and gas check, holy cow! Using a Lee push through .339 sizer I lightly coat them with case lube and run them through using my trusty Rock Chucker, even then it takes a bit off effort sizing from .342 to .339 without the gas checks. Trying to put on the gas checks is another story, the Hornady checks slip right on, but when running in nose first the die pushes the check down the shank before it crimps in place and the bottom edge of the check extrudes slightly around the top of the punch leaving what looks like a sharp edged cupped base. I even put a dab of lube on the sides of the checks. For who are wondering if I water quenched after coating.. i don't remember.

Running them through base first works better when it comes to seating and crimping the checks in place, however the amount of force required to do so causes the nose to flatten out a bit creating "new" meplats of different diameters resulting in bullets of different lengths. I thought about using my LAM with a top punch to avoid flattening the nose, although considering the amount of force it took with the RC I quickly dismissed that idea.

Having a couple of thoughts here.
1. As mentioned elsewhere PC adds a significant increase in hardness over naked bullets.
2. Size and check soon after coating i.e. hours vs years.
3. Try a different gas check.

I am open to suggestions here. Many thanks.

Michael
 

popper

Well-Known Member
Anneal the GCs. Get a larger punch. COWW + 5% lino - probably very hard now so size down in steps and clean the sizer.
 

Spindrift

Well-Known Member
If you heat your bullets to typical "baking temp", this will reduce the hardness of your bullets again. Sizing should be easier. Then, I would let the bullets "mature" by precipitation hardening at least 4 weeks before load development.
 

Michael

Active Member. Uh/What
The punch is one that came with the Lee push through. Next one up that I have is for a .356 die. Wondering if the die might need a bit of polishing, if it is possible to do. NOE's sizing bodies are sold out until who knows when, lots of body bushings an push rods though.
 

Dimner

Named Man
I water quench my PC bullets after baking at 425 for 25 minutes. I get a pretty good bump in hardness. And if my alloy is based on CWW that bump gets harder as time goes on. Plenty of other threads with the science as to why.

I ALWAYS size my bullets right after they sit in the water quench for a few minutes. No issues with sizing. However, if I wait a few days or a week it's significantly more difficult to size them.

As for pulling bullets that have been PCed this way, it takes a tremendous amount of muscle. I expand my necks to 0.002 under the diameter my bullets are sized to. So neck tension isn't crazy theoretically....but after a week or a month those bullets grow slightly or something... and I have a hell of a time pulling them.

I dont have a range in my backyard, so I'm always loading extras when I'm doing load development tests. Bullet pulling for me is just a part of load dev.

Edit to note: I have none of these issues with PC bullets baked the same way but air cooled.
 
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Dimner

Named Man
Spindrift has the right of it. If I were the OP, I would bake all those bullets as they currently are. Bake at 425 for about 45 minutes and then let them air cool. Once they are only slightly warm to the touch, just a bit over room temperature, add GCs if necessary and size. This will also make sizing after you PC much easier.
 

CWLONGSHOT

Well-Known Member
Yup lesson learned here too many years ago.

Like Tomme, I make it a rule to Powder Coat and size straight away to casting. Often same day always by end of next.


CW
 

Ian

Notorious member
I size PC'd bullets as soon as they reach room temperature, gives me something to do while waiting for the next batch to cure.

20 minutes at 400F from a room-temperature start is enough to anneal the bullets back to just-cast toughness. However, it takes 45-50 minutes at 425+ to reach the relax point required for a thorough quench-hardening.
 

Brad

Benevolent Overlord and site owner
Staff member
Sizing pretty hard bullets down .004 is going to be hard on everything.

This is why I would cast, check and size, then PC and resize. I would probably use softer bullets too but that is just me.
 

blackthorn

Active Member
Michael----You said:
"Having a couple of thoughts here.
1. As mentioned elsewhere PC adds a significant increase in hardness over naked bullets."

I can understand an increase in hardness caused by the constituents in an alloy but I am unaware of PC adding hardness. Could you point me to discussion on this ? Thanks.
 

Michael

Active Member. Uh/What
I agree, not the best choice of words on my part in regards to "increase in hardness". I knew what I meant but the words were not coming out to describe what the mind was thinking. Bullet hardness itself is not actually increased by the simple of adding a PC, but the surface is toughened, strengthened, or has increased resistance deformation as stated above by RB with the addition of PC.

Thinking back to my first thought, with the addition of the PC creating a tougher surface adding to the sizing and/or the seating of gass.
 

Winelover

North Central Arkansas
Heat them to 400 for 1/2 an hour then let air cool. Then size and check them. This is why I size an check all of my bullets right out of the oven.
I size and check mine, before going into oven. I don't/won't do water quenching.
 

Dusty Bannister

Well-Known Member
I do not think "Surface Toughening" is correct either. The PC only provides a barrier between the barrel and the lead alloy of the bullet. If there was hardening of the surface of the bullet, it would work soften when sized after any alloy hardening from bake and quench. Harder bullets might also be expected to resist engaging the rifling but that does not seem to occur either. This is kind of getting lost in the weeds.
 

Tomme boy

Well-Known Member
Most of my molds I can put on the check after baking no problem. But a few I have to do before. Either way it does not matter. The thing is if you are using a alloy that is going to get very hard, do it as soon as possible. Sometimes a day later is too long to wait.