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View Full Version : What to size boolits for revolver?



mto7464
06-12-2008, 11:14 PM
Throat of the .38 is .357 and cylinder is .355. I am casting using wheel weights. Any recomendations for size? This is my first attemp with a pistol load.

okay okay you can tell I am not a revolver man. So it looks like I need to open her up like 454PB says.

454PB
06-13-2008, 12:20 AM
That doesn't make sense. The throat is the narrow area at the very front of the cylinder. Are you saying the throat is .355" and the bore is .357"?

If so, you're going to have accuracy and leading problems. The solution would be to have the cylinder throats opened up to at least .357".

kir_kenix
06-13-2008, 12:28 AM
If the bore is .357 and the cylinder is bored .355 you are going to have some serious problems. As 454pb already mentioned, you need to have someone open up your cylinder to match your bore. If it is a new production, this might even be a warranty issue.

Bass Ackward
06-13-2008, 06:13 AM
Wow. A real challenge for your first attempt.

44man
06-13-2008, 07:28 AM
Well, the way he explained the dimensions, it is a challange for all of us! :mrgreen:

prs
06-13-2008, 10:47 AM
Harrrrrrrrrrrrrr! Must be a Rooger. His only problem, if his description is correct, is that it will not chamber standard 38SPCL (357 or 358 ammo). Rooger is kinda funny about setting cylinder throats smaller than bore on some guns. My 45 Colts had to be reemed to shoot lead boolits in top form. I have heard theory that the odd dimensions somehow favor copper condom bullets - but the logic of it escpes me.

Slim; who shoots .454 boolits through .4535 throats into .452 bores --- and who can't recall what the cylinders measured, but plenty dern big fer sure!

prs

GabbyM
06-13-2008, 11:18 AM
Someone jog my memory.
Wasn't that Colt who made 38 Special revolvers back fifty years or so with those small throats?

Ricochet
06-13-2008, 11:31 AM
My 1953 Official Police has a .355" groove diameter.

Bret4207
06-14-2008, 08:28 AM
MTO- could you provide some specifics like make and model and just where you are measuring? If the throats, the mouths of the cylinders, are smaller than the throat/bore/area ahead of the forcing cone of the barrel then yes, there can be problem. If you could clear that up we'd be in a better position to offer advice.

As a general rule you want to size to fit the cylinder throats. Barrels are usually/supposed to be smaller than the cylinder. Some guns (Rugers/Colts) have had the opposite problem of a barrel larger than the cylinder which means you have a boolit rattling down an over sized bore. Personally I size as large as the cylinder will accept in most guns with standard type loads given the difference being less than .002 or so. For max loads this can cause problems, but in light to standard/medium loads it works pretty fair for me. Some folks prefer to size to the specific bore diameter or not more than .0005-.001 larger and use harder alloys. You need to find what works for you in this game.

mto7464
06-14-2008, 09:03 AM
maybe I measured or slugged improperly. I slugged them with some soft lead but perhaps I should try again. The pistol in a model 36 S&W. Like I said this is new to me. I haven't loaded for pistols in over a decade and that was my 45 ACP and not cast.

calsite
06-14-2008, 10:44 AM
I'd double check my measurements and hope I was wrong the first time.

miestro_jerry
06-14-2008, 02:47 PM
I would check the measurement again and then slug the cylinder and the barrel.

Jerry

pjh421
06-14-2008, 03:43 PM
Go to the hardware store and buy a suitably small diameter brass rod Steel is not advisable. Get some cast boolits from a friend or buy a box of them from your local gun store. Drill a couple of holes in a 2x4 of about 1/2" in diameter each so they make a figure 8. Leave this in your vise.

Remove the cylinder and crane assembly from your Smith. Leaving the extractor rod in place put the cylinder minus the crane on the 2x4 with the extractor rod pointing down and passing through one of the holes. Line up chamber number one with the remaining hole in the 2x4. Drop in a cast boolit.

Using the brass rod, carefully tap the cast boolit through the throat portion of chamber number 1. Use a Sharpie marker or something similar to keep track of which chamber is number one, two, etc. unless your cylinder has the "V" stamp to so indicate. Get out your micrometer and measure the major diameter of the newly-sized cast boolit. Write this down. Repeat for the remaining chambers.

If your throats are squeezing your boolit down smaller than or even perhaps equal to .357" you will more than likely have to stick to jacketed bullets because when the undersize boolit enters the bore of the barrel there will be an inadequate gas seal. This is no different than having worn compression rings on the pistons of your engine. Using jacketed bullets at the ranges this gun was designed for probably won't present any problem. However, when you use a cast boolit in a gun with dimensions such as these you will likely get leading.

If you want to put some money into this gun so it will shoot cast boolits properly you will need to have the throats reamed a bit larger (and it never hurts to have them all the same size). Here is a link to a guy who does this from the Mountain Molds website links page: http://www.cylindersmith.com/

Paul

mto7464
06-14-2008, 10:30 PM
Well I loaded some up sized to .358 with Lino over 3.2 grns 231 and they shot fine. No leading. Accuracy, who cares, it is not designed for that anyway.

Bret4207
06-15-2008, 07:37 AM
Good enough, but don't sell that belly gun "short". My S+W Airweight Bodyguard loves my H+G #50 WC backed by 2.7 gr BE. If the guy behind the wheel does his job they make nice round groups that are surprisingly small- about 1.5 -2.0" at 10 yards. With my eye sight (it's a wonder they let me drive!) and that short sighting radius I was amazed.