lead bullet confusion

[greenwood county cowboy]

i was looking at black powder pocket pistol and there calibers are .31 but then i look at lead balls and i dont see a .31 caliber it only goes down to .32 caliber..............i saw a box that said .310 but then on the top of the box it said .32....soo is a .31 really shoot .32 caliber bullets

[greenwood county cowboy]

well i found a caliber called a .31 colt... is that only for colts or can i shoot it out of a remington pocket pistol

[knucklehead]

i was looking at black powder pocket pistol and there calibers are .31 but then i look at lead balls and i dont see a .31 caliber it only goes down to .32 caliber..............i saw a box that said .310 but then on the top of the box it said .32....soo is a .31 really shoot .32 caliber bullets

I am not sure how the powers to be determine what the bullet diameter is for the black powder cap and ball handguns.
hopefully someone on this wire will explain for us.
what i do know is the round ball needs to be big enough in diameter that when you seat the ball ontop of powder you will shave off a ring of lead.
I have this same poket pistol. I use .319 for round balls. I get a small ring of lead shaved off with this diameter of round ball.

[hellgate]

Man, I hope I've got this right. The BP firearm calibers were designated based on bore diameter and THEN riflings were cut into the bore i.e. the barrel was "bored" to the stated diameter. So a patched round ball was smaller than the bore diameter when fired in a RIFLE. For example, a 45 cal rifle fires a .440 ball. For the C&B revolvers, the "bored" diameter for a 36 caliber is (probably) 36 cal but then riflings are cut into it and the groove diameter will be larger. In order for the plain lead ball to seal the bore it needs to be larger than the bore diameter to fill in the riflings so the 36 cal revolver uses a 37-38 cal ball which is rammed into the chambers which are also larger in diameter than the bore. So, a 44 Remington or Colt C&B needs a .451-.454 diameter ball to fit into and seal .448"dia chambers and fly through a .44 diameter bore (groove dia is likely about 45 cal).

In newer smokeless guns the groove diameter is often used to determine the caliber. In the older calibers it's the "bored" (land to land) diameter. 

Then you get the 38 SPL that shoots a .357 dia bullet. If memory serves some of the earlier 38cal cartridge bullets were healed and the outer diameter was the same as the cartridge case. I haven't measured it but a 38SPL is probably 38 cal outside diameter of the brass but the bullet is inside the case and therefore is smaller.

Yes, it is confusing so that is why we all need to read and believe the reloading manuals when we are starting out and periodically thereafter. I'm starting to appreciate the metric designations for the various calibers.

[Dr. Bob]

From memory!

What hellgate said is right for percussion revolvers.  When they started making cartridge revolvers, the kept the same bore diameter but call a 36 caliber barrel .38 to differentiate it in the mind of consumers.  For example, 38 S & W takes a .354 .to 360 diameter bullet.  [All specs from the 44th edition Lyman Reloading Handbook, 1967] However, the 38 - 40 Winchester takes a .400 to.401 bullet. I is similar for the .44 calibers.  The Henry in 44RF and the 44 Colt, 44 S & W Russian and 44 Special  all use a .427 to. 431 caliber.  The 44 - 40 Winchester uses a .425 to .429 bullet The 45's are generally .450 - .454 for revolvers and .458 +/- for rifles.

All this makes the European system of mm X mm seem quite simple.

I'm sure that this is clear as mud! 

As for .32 caliber,  the 32 S & W takes a .310 to .311 bullet.  BUT, the 32 - 20 Win. takes a .311 to .312 bullet while a 32 - 40 Win. uses a .320  to .321 bullet. 

They made it SO EASY.

[Delmonico]

I'm starting to appreciate the metric designations for the various calibers.

So most 8mm rounds made in Germany have two seperate rounds, one using a 0.318 bullet and one using a 0.323 bullet, there are at least 3 6.5X58 rounds although 2 of them are 6.5X58R meaning rimmed, there are other just as confusing rounds.

[Brian Why]

AFAIK .31 caliber barrels are around .315 - .325, depending on the manufacturers' mood (or so it seems). The best thing to do is slug the barrel to find out the best ball size for it. Search the archives for how to slug.

I have a pair of .44-40 '73s that are 32 digits apart and one is .427 and the other one is .431, so ya never can tell til you check 'em out.

[Dick Dastardly]

My lil spur trigger Remington .31 shoots .32 S&W ammo loaded with my Big Lube™ 80 grain RNFP bullet.  That bullet drops from the mold at .3145 and I lube/size it to .314.  The barrel in that gun is rougher than a cob.  The groves are fairly smooth, but the lands are full of machine marks.  I'm thinkn' the barrel was really rough when the rifling was put in and it left the lands with those marks.

The gun has a Kirst Konverter cylinder and shoots reasonably well with it.  The original C&B cylinder is way under bore and if I had a shotgun that patterned that bad, I'd sell it.

This is my gamblers "hideout" gun.

DD-DLoS

[Cuts Crooked]

...and so you see, Greenwood, you need a .32 ball or larger fer that cap pistol! It's all very cornfusing, I know, and the pards have made it about as clear as it's gonna get fer now.

Bottom line, regardless of the actual bore diameter, you need a ball that fits THE CHAMBERS and cuts  a thin ring of lead off as it is being seated.

DD brought up something that is a bit of a problem with C&B gunz, in that manufactures aren't making them right. They are making the chambers smaller than the bores, which can lead to serious accuracy problems. However, not always. I've had the chambewrs reamed on tweo of my C&B cylinders because of this....something else fer ya to check into wif that new shooter.