I'm not home to give you exact measurements, but if the die looks like it fits on the end of the barrel, you should be pretty close.
Most dies have a screw that allows you to adjust diameter a small amount. Start with the adjustment set loose, so you're cutting shallow threads. This makes it easier, more accurate, and you're less likely to damage the tool. After completing the first pass, tighten it up a bit, and make a second pass. Continue until the threads are deep enough. Usually two passes are plenty. Be sure to tighten the die in the handle well.
Use plenty of oil, and go slow. 1/4 -1/2 turn and then back off. Remove chips frequently. Stuff a couple patches in the barrel to keep crap out of it. I've found it a lot easier to put the barrel in a vise so you can use both hands on the die.
I prefer to use a pilot when doing threads by hand to keep the threads as straight as possible. The pilot threads into your die so that it keeps it straight. Insert the pilot in the die so that you have 3-4 threads available for cutting. As you start cutting and make 2-3 revolutions, move the pilot back up into the die to make more threads available for cutting. You can secure the pilot on the back of the die with a muzzle brake.
Apply pressure evenly and smoothly to start. Once you get a few threads going, it will be easier. The temptation will be to go faster. Don't.
Az