Opening Chokes

[William Davis]

Here is a question for the experienced. Am not a gunsmith or machinist, do have a lathe and have been a hobby gunsmith for a long time. Looking at many SxS shotguns have seen mostly very poor opened choke jobs, you can spot them right away.

Way I have always done deep hole drilling is drill the hole first then turn down the outside to make the finished job concentric. Never filed a shot gun barrel but my guess is the inside bore work choking and polishing was done before the barrels were filled outside. If not to finished at least the majority of inside work was done before the outside was filed.

When the outside was filed the gunsmith finished muzzles up to have a minimum thickness. No doubt if he needed to take more weight out of the barrel he did it away from the muzzle. Mark of a factory choke is plenty of metal at the muzzle everything concentric no thin or thick sides.

100 years later open up a choke result is a very thin wall thickness at the muzzle. And if opening up it takes a very good workman to keep the finished job concentric. Working by hand with a reamer I doubt if there is a 10 % chance of the finished job coming out looking like a factory muzzle. Chucked up in a lathe everything carefully set up perhaps the chances are better, still it takes a very good man to keep things centered when right or wrong is couple of thousandths you can spot with your eye.

Am I missing something or is my theory that open jobs go wrong more that right correct. Are there gunsmith that can alter chokes that can’t be spotted from factory? Might be I never spotted good open jobs because they were good.

I get open patterns with Spreader loads, just thinking about how open jobs are done, don't plan to have it done to any of my guns.

William