357 cyl throats
- Thread starter Tomme boy
- Start date
A mild snug fit is as tight as you want. My match revolver has .357" throats in all 5 holes, I size .357" and my alloy in my sizer die leaves them a couple of tenths smaller. I can place a sized bullet in each throat, and they don't slip thru. Takes only a pencil to tap them thru.
L Ross
Well-Known Member
^^^^^^^ that.
Monochrome
Active Member
What make and model of revolver do you have? see what the barrel is at, and see what the combination comes out to. You may have the idealized chambers. Or you may end up with .357" throats and a .361 " bore..
That other revolver, is it a taurus by chance?
Petrol & Powder
Well-Known Member
I recently measured a newer S&W model 64 and found that a .357”+ pin gauge would pass and a .3575”+ gauge was a no-go. This mirrors what I have found with many S&W 38/357 revolvers. The S&W family appears to be very consistent in this regard. To obtain accurate measurements, the throats must be perfectly clean. This may require removing the cylinder from the gun and spending some time with an appropriately sized bore brush, a Lewis Lead Remover, or some other tool. A short, non-rotating cleaning rod is best for this task.
Slugging the bores of various S&W revolvers reveals groove diameters are also around .357” and consistent (although I have encountered some thread choke on some examples but not nearly to the extent that some Ruger’s exhibit). Colt is an entirely different ball game and I seldom play in that sandbox.
I previously sized bullets to .358” for use in S&W and Ruger revolvers but abandoned that method and I now size to .357”. That change to .357” increased accuracy slightly and decreased leading. It re-affirmed all the old instructions to size to the cylinder throat.
The cylinder throat is the last sizing die the bullet will pass through before reaching the barrel and it has the final say. It is my belief that a snug but not excessively tight fit is what is needed. A bullet that will pass through the cylinder throat with just a little bit of force applied is ideal.
Slugging the bores of various S&W revolvers reveals groove diameters are also around .357” and consistent (although I have encountered some thread choke on some examples but not nearly to the extent that some Ruger’s exhibit). Colt is an entirely different ball game and I seldom play in that sandbox.
I previously sized bullets to .358” for use in S&W and Ruger revolvers but abandoned that method and I now size to .357”. That change to .357” increased accuracy slightly and decreased leading. It re-affirmed all the old instructions to size to the cylinder throat.
The cylinder throat is the last sizing die the bullet will pass through before reaching the barrel and it has the final say. It is my belief that a snug but not excessively tight fit is what is needed. A bullet that will pass through the cylinder throat with just a little bit of force applied is ideal.
Monochrome
Active Member
on a certain forum, its always been "measure chamber throats, ream them all to the largest measurement you get, size a cast bullet .001 over that, or over bore diamter and shoot"
That is a fine solution to those that desire cylinder leading. Yes, all throats should be identical. Bullet fit in the throats should be a mild snug fit, if you can't tap the bullet thru the throats with a pencil it is too tight. For best accuracy the bullet weight (length) should have the front driving band inside the throats when the round is chambered. Only one reason to slug a bore on a revolver, to make sure that it is not larger than throat diameter.
Monochrome
Active Member
but the guy who convinced everyone that has to be done, makes a good living reaming chamber throats for people on that forum
Petrol & Powder
Well-Known Member
I had a GP-100 that was a problem child. Throats were small and about 4 different sizes. Considerable thread choke in the barrel where it passed throught the frame and a few other issues. I reamed the throats so they were all equal and fire lapped the barrel. That Ruger steel is TOUGH and I never complaetely removed the choke but it shot far better when I had the barrel and throats on the same page. I eventually sorted it all out but sold the gun when the project was completed.
Tomme boy
Well-Known Member
model 66 4" Taurus is the one that is a little tighter. The other is a Taurus Tracker with a 6.5" barrel. They both are shooting the 0.358" bullets fine. The only thing I do not like about these guns is they have a very short cylinders. The cartridge length is very critical with some bullets. As is the crimp. I was using a Redding profile crimp die on a few bullets and they were jumping the crimp. I had to go back and use a regular crimp die to do a regular roll crimp. Then no issues.