I've got a box of Hornady gas checks cooling down from being annealed. I put the checks in a skillet and blacken them, then let them air cool.
A while back I tested annealed verses straight from the box checks in a 243 using bullets from the same batch of bullets. I noticed a difference in the accuracy edge going to the toasted checks.
So I toast all of my checks for the 375 Whelen and the 45-70.
Does any one else used blackened checks.
Jim

I started "toasting" my checks about a month ago. I believe I also am seeing a slight edge in accuracy. In addition I've noticed that in the past with as purchased checks they tended to "shave" off bits of metal as I sized them. These bits of metal ended up in the lube grooves of the bullets. I also no longer get any spring back of the checks after sizing. This used to leave a slight bulge in the neck of the cartridge.

I place mine in a short pipe with caps on either end and suspend it in molten lead at 750 degrees for an hour (30 min probably would suffice) and let air cool. To keep the oxidation of whatever finish/lacquer? on the checks I put in 1/2 sheet of Charmin toilet paper it seems to work as most of the checks stay fairly shiney and soft. I'm not sure if other brands of toilet paper will work as well since Charmin is so soft.

Have Fun,

JCherry

hmmm.. Have you ever made the tool Col. Harrison talked about in his book. The one to "spread" the checks out so they fit over the base, seat, and then crimp on? It took maybe 3 minutes to make and was the single biggest improvement in accuracy I have found. No more damaged bullets by the checks. I have never annealed them but that might help. I have pictures but have had terrible luck posting them. If anyone is interested, email for piks of this tool and the homemade check maker too.... Or can someone post them for me?

The only time I had trouble seating gas checks was with the straight sided Lyman checks. Once I switched to the Hornady checks the problem disappeared.
I scrounged an 11 by 16 piece of 1/2 inch plate glass to use for installing gas checks. By this I mean, I use my fingers to press fit them on the base of the bullet. Then I use a small piece of flat steel on the bottom of the sizer and a flat nose punch like I was sizing and lubing in the Lyman sizer to finish pressing the check on the base.
Then I run them thru the machine for sizing and lubing.
Jim

I believe that gas checks, being a copper alloy, will anneal best if you get them hot and then quench them. Unlike steel and iron alloys, brass and copper harden when air cooled. This is why you quench a case neck when annealing. Or so I was told.

Trooper
You may very well be right!
It was my understanding that the neck annealing step, quenching after heating, was to just cool them down to prevent the base and web of the case from getting soft.
It was my understanding that brass, bronze, in our context, got work hardened and the heating relieved the work hardening.
This will give a good reason to run a batch of experiments, gas checks raw, gas checks heated and air cooled and gas checks heated and quinched.
I'll let you all know what happens.
Jim

Pete, you are correct, and Bret you heard the wrong answer. The heating-the-pipe method works best because it keeps the copper from "rusting". Must have the paper to char/burn to consume the oxygen, creating co/co2 which does not harm the copper at those typical softening temps. ... felix