gauge or bore

[swamp]

20 gauge or 20 bore... 12 ga or 12 bore... etc.... does any one know specifically what bore size means...

[ncboman]

As I understand it, the gauge has to do with how many equal loads a gun will get from a pound of lead. Bore is a European term and I assume the actual bore size although I'm not sure about some of it.

web page (http://en.wikipedia.org/wiki/Gauge_(bore_diameter))

[Altjaeger]

In the case of shotguns the terms gauge and bore are interchangeable. Except for the .410 which indicates the caliber or diameter of the bore in thousandths of an inch the bore is determined by the number of balls that can be cast from a pound of pure lead that match the cylinder bore of the gun. Now settled largely at 10, 12, 16, 20, 28 and 32 gauge or bore at one time there were 4, 8, 14, 18 24 and assorted other bore sizes. Simply put if a perfectly round ball round fits the open choked 12 guage you should be able to get a total of 12 balls that size from one pound of lead, 16 from a 16 gauge and so on.

To further compound the confusion paradox guns were measured in bore, but were rifled the last few inches of barrel to increase the accuracy of shooting ball while retaining the ability to use shot, I would not bet on how effectively but this was pre-nitro powder. All arms were inefficient by our standards, but modern for their era.

Sir Samuel Baker used the 4 bore and 8 bore as his elephant guns and market hunter punt guns were often near 4 bore. Looking at an online gun auction recently I saw an 11mm rifle/26 gauge shotgun antique European combination gun.

[swamp]

Alt, I had wondered about it and finally read that a 12 bore diameter bbl would accept 12 perfectly round lead balls that would weigh exactly one lb... etc etc.. I dont think that is commonly known among most gun enthusiasts....

I wonder what the bore of a 410 is... ?

[Altjaeger]

I wonder what the bore of a 410 is... ?

Remember above I said it was .410 caliber. Technically caliber is a method we use to measure gun bores, most particuliarly modern rifle, pistol and artillery and "a caliber" is 1 inch. Therefore the 410 is really 41/100th of an inch or .410 caliber. We do not have a .30-06 caliber though it is common in colloquial usage. We have a .30-06 cartridge that shoots a .30 caliber bullet. The U.S. Army has 8 caliber howitzers commonly referred to as 8".

[kjjm4]

..I wonder what the bore of a 410 is... ?

The density of lead is 2 867.8 grain/cubic inch. A .410" diameter sphere has a volume of 0.036 cubic inches. So a .410" ball should weigh around 103 grains. There are 7000 grains in a pound, so you can get around 67-68 .410" diameter balls from a pound of lead.

[Twanger]

The density of lead is 2 867.8 grain/cubic inch. A .410" diameter sphere has a volume of 0.036 cubic inches. So a .410" ball should weigh around 103 grains. There are 7000 grains in a pound, so you can get around 67-68 .410" diameter balls from a pound of lead.

So a .410 would be a 68 guage! (or there-abouts)

I use Hornady 0.395 round balls in my .410 pistol with a thick patch. They weigh right about 100gr.

[GF.]

But why in tarnation would anybody invent a shotgun, measured in caliber, and in such a puny size.... :hmmmm:

The most probable explanation I've ever heard was that there were a lot of cheap, rusted-out .45/70s around in the hands of dirt-poor farmers who needed something cheap to pot-shoot a little dinner; I guess the hull thickness of the shotshells constricted the slugs to .410...


Can you imagine the 'accuracy' of a .048" underbore slug in a rusted-out, partially-rifled barrel? Those guys must've pretty good when it was time to injun up on a critter....