I load the Lee CTL312-160-2R in my SKS and 54r rifle I apply the gas check with the Lee .314 push through sizer so as not to size the bullet any and it works just fine.
Apply a thin coat of the Lee Alox to the bullet and let dry before pressing the gas check on and pushing it through the sizing die,then TL the bullet once more before loading.
Lee only makes a stock .311 or .314 sizing die you can also customer order one in the size you desire but the wait may be a couple month and cost is around $30 US.
You can also customize your own sizing die by buying one that is smaller than the desired finished size and honing it out to the desired dia.
What you will need:
1) A size die that is as close as possible to what you want
2) A length of steel rod that is close to 3/4 of the diameter of the existing die, and long enough to protrude at least 2" beyond both ends of the die.
3) Wet or dry emery paper of 320, 400, and 600 grit. If you do need to remove more than a couple of thousandths you should also include 220 grit. Actually the 400 will finish the inside well enough, but hitting it with a bit of 600 sure slicks it up.
4) Oil. Most any oil will do.
What you do:
The paper should be cut long enough to extend out either end of the die, almost as long as the steel rod. Wrap your starting coarsest grit paper around the steel rod a couple times and apply some oil to the paper. Insert the covered rod through the size die. With just your thumb and a couple fingers on each end of the rod, roll it up and down your thigh (while sitting) applying only mild pressure. The reason for using a rod as large as possible, is to keep from tapering the inside of the die, by having a slender rod bend under pressure.
Roll the steel rod occasionally as only a small portion of the paper is in contact with the interior of the die. You should also swap the die end for end every now and then to make sure the metal removal is as even as possible. Remember the throat of the die is tapered to admit the bullet and we're only wanting to open up the actual sizing portion of the die.
When you check your work you don't need to put the die back in the press. Just drill a hole in a board bigger than the bullet and place the die over it. Place a bullet in the die and tap it through. Remember to leave a bit of metal to remove for your polishing down to final size with the finer grit paper. The first time I did this I just took it down to where I wanted it without thinking of the finish.
