I believe your mold arrived here today. I should have it on it's way back in a few days.
Mr Debois: Definately try annealing first, and remember that checks get squeezed about .008 deeper when they enter the rifling, so it they stay on so handling bullets while loading is uncomplicated, they will shoot perfectly.
About springback after sizing gas checks. It also happens after they exit the muzzle if the check metal is extra hard, and the rattling gc is harmful to accuracy, as it causes a slight vibration in the bullet. Most handgunners will never know, but benchrest rifle shooters will see it clearly.
The simplest way to anneal is to lay a ring of checks around and electric range burner. Turn it on, with lights off in the room, and do it in the evening if a well windowed room. When you see the slightest red appear, turn the burner off, wait till the checks are cool enough to handle, and pick them off. If you fill all the burners you'll probably get most of a box of checks done in one run.
Another excellent method is to put them in a black iron pipe nipple with cast iron caps on each end and submerge it in your lead pot. DO NOT USE GALVANIZED PIPE OR FITTINGS FOR THIS PURPOSE, ESPECIALLY IN YOUR LEAD POT! Melt temp should be 850 - 900 deg F. Leave it in the melt for at least 20 minutes so the heat can penetrate through all the checks. Remove and when it's cool enough to handle, unscrew one of the caps and your checks are annealed. 700 deg will soften them adaquately, a dull dark red in a very dimly lit room is about 800 deg F and excellent, while heat up to 1100 deg won't hurt them. 1100 deg will be a fairly bright red. (1200 deg is fairly dark yellow, and 1400 deg is bright yellow. Those are blacksmith temperature measurments, by the way, when heat treating steel.)
So the nipple / pipe cap annealer can be heated any way thats easy for you, including a campfire.