... Trying to find a use for a 1/2 oz .410, or 3/4 oz 28, through .000 is another. How useless? Well, at 20 yds you will not reliably break a centered clay with the .410 and #9s. Nor will you reliably tag a centered grouse or WC with the 28 and US #8s. Sometimes you will, sometimes you won't. ...
Sam
Sam,
I may have inadvertently discovered another method of tightening the little .410 pattern, regardless of choke or cylinder. Years ago, I bought that little LeFever Nitro Special .410 with all the engraving and new wood. The barrels are pitted and the chambers had been lengthend by a hack with a common 45 degree lead chucking reamer. I took careful measurements and had a chamber/forcing cone reamer made from a "taper pin reamer" (1/4" per foot taper). It fixed that gun's chamber problems. I've always shot that gun well and taken quite a bit of game with it, sometimes at pretty long distances for the IC/MOD choking.
Recently, I used that reamer on another gun to go out to 3" chambers. (It produces 3" forcing cones if you haven't calculated it by now.) I noted that the right barrel had been openned to cylinder. When I started shooting it on the pattern board, my friend that shoots .410 exclusively, was there. He was so impressed with the pattern desity using the same factory loads he uses in his guns (mostly his CSM 21, but also P-guns and M42's) that he begged me to open up his CSM 21 chambers on both sets of barrels.
I think the effect of a gradual forcing cone reduces the damage to the shot. Since the 3" .410 has more percentage of shot in contact with the bore than any other bore size, the effect is magnified.
These taper pin reamers are available from many industrial supply sources on the net for not much money. Finding a cutter grinding service was easy for me, since I know people in that biz. But, any area with industrial machining will have a cutter grinder biz base of some kind. The chamber body diameter (which is slightly tapered), is simply "spun" (ground by spinning the cutter between centers on the countersinks in either end), without any "relief" since all you are doing is cuting the forcing cone.
Try it on one of your .410's, I think you'll like it.
