aneling aluminum for GC

Kevin Stenberg

Well-Known Member
There was a comment in a thread about aneling aluminum GC. I tried last night to anele the aluminum strips before I punched the checks out.
My process was. Cut the roll of aluminum (4"x 50') into 2' lengths. Put the strips into the oven set at 300 deg. for 1 hour. What do I need to change to anele the strips properly?
 

Rick

Moderator
Staff member
I've never done it but I just googled annealing aluminum and came up with this . . .

Aluminum annealing can be performed at 775°F for 2 to 3 hours followed by controlled cooling at 10 to 260°C (50 to 500°F) per hour, and air cooling.
 

Stonecrusher

Active Member
If I ever find the need to anneal my checks made from Amerimax flashing, i just scatter them on the top of the hotplate until they change color a bit. Now, I also use some .02" thick aluminum sublimation stock, sort of like litho-plate, for my 7.62x54R bullets to get the .3165" dia. This mat'l will often develop stress cracks at the corner of the base of the check when formed that cause fliers. It took me a little while to figure that one out as the cracks are almost invisible. What I do with this is heat the strips with a propane torch hot enough to burn the coating off and leave the check looking kind of smokey.

I know the heat and time involved isn't enough to fully anneal the aluminum, but it stops the stress cracking and spring back so the checks crimp on really tight. Also, if measured with a micrometer they are the same size as the rest of the bullet. Without any annealing the checks seem to wind up almost .0005" over the bullet diameter after sizing. I haven't noticed any difference in accuracy either way, except for when they are cracked.
 
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Hawk

North Central Texas
I anneal my aluminum and copper gas checks in a small cast iron skillet, 5"-6" diameter, on a Coleman stove. Just heat and shake till they change color.
Doesn't take too long.
 

Brad

Benevolent Overlord and site owner
Staff member
Makes them softer and removes any tendency to spring back. In some cases it helps them really hold onto the bullet shank.
Annealing the Al before cutting and forming the checks would make them easier to form.
 

Rally Hess

Well-Known Member
One of Brad’s check tools really makes them work better also. I’ve even used it to make .30 checks out of .32 checks.