.44 special cylinder throat vs bore diameter question

[35remington]

Asking even a soft lead bullet to obturate beyond the forcing cone is asking a lot at 44 Special pressures. Since it is well beyond the case mouth and pressures are plummeting it likely won't happen.

since that's in agreement with what's been said before I'd fix the revolver too.

just a comment.....we say "bore" when we really mean barrel diameter way too often around this place.

[MtGun44]

Al -
I had a pretty good idea that distractions and disgust would be major
players in that mini-drama. Been there, done that. I wish I could
run as linear and thorough a testing plan in my private life as I could
when I was doing if professionally. Too many distractions and competing
required things that must be done, and no doubt the irritation factor
isn't there when it is somebody else's "stuff" and time and money.

Bill

[daleraby]

I have a Ruger/Lipsey Flattop .44 Special. Chamber throats measure .432 (using a .440 round ball driven through the throat with a punch, then a Lyman dial caliper to measure the slug). Groove diameter at the forcing cone was bad enough that I could feel the threading constriction with a patch and fitted jag while cleaning it. When I first got the gun I did not have the dial caliper, but knowing that Rugers in .45 & .44 have a tendency to crush down the barrels at the forcing cone, I ordered a Wheeler Bore Lapping Kit The bore lapping procedure made me nervous, but I managed to enlarge the forcing cone enough to where I could barely notice it. I still experienced leading though.

This morning I did a bit more lapping, this time cleaning the bore and using a measured slug. After firing two .430 255 grain cast bullets over 4 grains of Trail Boss (using the 600 grit abrasive compound), I could no longer feel any constriction. Slugging the bore produced a diameter of .430... the same diameter as the bullets I am shooting. I haven't determined a procedure to measure the bore diameter beyond the forcing cone, but I'm pretty sure there is a way to do that. Accuracy with my old eyes is questionable, but good enough for my purposes, though I may order the next batch of bullets sized a bit larger.

As to the aforementioned Wheeler Bore Lapping Kit, their procedure is to apply the abrasive to the bullets before using and then loading them into the case. This is a messy procedure that will leave residue in your dies that will require removal before using the dies again. This morning, I just put the compound on the exposed band of a the Keith bullet with a bit more compound forward of it, figuring that upon firing the gunk would be driven back toward the bullet. I would think that a better option might be to use a cut-down cartridge or maybe a .44 Russian cartridge, load it light, seat the bullet with most of the driving bands exposed and then apply the compound to the loaded shell. You should not expect any level of accuracy with bullets used in the lapping procedure. This would keep the grit out of your dies.

[35 Whelen]

Several years ago I bought a forcing cone cutting kit that cuts forcing cones to 11°. Now every revolver I buy gets the treatment. My Uberti Frisco had a minor flaw in the forcing cone so I recut it-



With one of my Uberti Hombre's I took it one step further, I cleaned up the forcing cone then did a little fire-lapping-

Before-

After-

This revolver is now smoking accurate and leading was greatly reduced.

35W