Opening up 44-40 chamber in '73 Winchester

[fourarmed]

Some years ago I had the barrel on my '73 relined by Redman. He advertised .428 groove diameter. It turned out to be at least .431. A .431 bullet seated in any of the readily available cases chambers too tightly for my comfort in a '73. What I would like to do is lap out the neck of the chamber. I am thinking of turning a short cylinder of brass that would screw onto a cleaning rod, then coating it with lapping compound or emery cloth and pulling it into the chamber from the muzzle using a cleaning rod, and spinning it with a hand drill. I suppose I might have to make two or three in graduated sizes to gain the clearance needed. Any suggestions are welcome.

[leftiye]

If it's only 2 or 3 thou - you don't say how much you want to open the neck area up, then either run a chambering reamer with the desired neck into the chamber, or a chucking reamer. You can probly drive it by hand. Chucking reamer will center on small cuts, especially if you're careful to put no side pressure on it.

[fourarmed]

There is no easy way to work from the rear in a '73, and I don't want to take the barrel off. This has to be something I can pull into the chamber from the muzzle. Are chambering reamers available with neck diameters different from SAAMI standard?