What classifies a small/medium/large(big) bore rifle?

D

Deja vu

New member
The other day I was at the range and a guy said his 338 was a big bore rifle. I did not say any thing but I thought that it was a very powerful rifle but in my mind a big bore rifle has a caliber that starts with a 4. While Medium bore starts with a 3 and small bore starts with a 1 or 2.

So is there a definition of "big bore" Vs Small bore?

:confused:
 
Everyone has a different idea of how to define them, including me.

My own opinion:
up to .20 = Small caliber (or "sub-caliber" - even though it's improper use of the term)
.22 to .257 = Small bore
6.5mm to .375 = Medium bore
.40 and up = Big bore



But, you may notice that most "official" references to the term 'small bore' are almost universally citing .22 rimfire rifles. They aren't necessarily defining the term, but setting standards or rules for a type of competition or event.

Likewise, most references to 'big bore' are almost universally citing .40+ bores, but not really setting a hard limit; and they generally don't include cartridges like .44-40.
 
In NRA competition, small bore refers to .22 rimfire rifles.

Years ago, a neighbor who hunted big game in Africa said the British system called small bore anything below 30 caliber. Medium bore was 30 to 40 and big bore was any caliber over 40.

There's probably a few different naming conventions. Different strokes for different folks. . . . . .

http://www.chuckhawks.com/medium_bore.htm

http://www.chuckhawks.com/intro_big_bore.htm
 
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I think a better way to classify them is

small game calibers
deer calibers
American big game calibers
African big game calibers

It's bullet energy as well as bore. A .44 Magnum is certainly not a African big game caliber.
FWIW, Africa has small game also and calibers such as the .22Hornet are actually quite popular there.
 
The beauty of the American system for designating caliber is there is no system. It doesn't make sense and that is the way it is. It is also what makes a lot of our discussions fun. Americans like to do what they want the way they want. Europeans like everything neat and welll organized. I call that boring.
Small, medium, large? Pick yer pizzen and enjoy.:D
 
I think a better way to classify them is

small game calibers
deer calibers
American big game calibers
African big game calibers
Click to expand...
This seems like a good way to look at things.
Click to expand...
That's essentially what the old European system was designating.
With black powder as the most common propellant, and a major limitation to cartridge performance, all that really mattered was "how big and how heavy".
Bullet diameter and weight determined what the cartridge was good for.

Later on, you had terms like "Express" added to some cartridges, to designate light bullets at higher velocity (rather than the "standard" for the cartridge).

With the introduction of Cordite and Smokeless powder and expanding jacketed bullets, most of the small/medium/large-bore references fell apart. It was a new era, where each cartridge could be judged on its own merits, rather than just bullet diameter and weight.
 
I think a better way to classify them is

small game calibers
deer calibers
American big game calibers
African big game calibers
Click to expand...

I like that as well.

Years ago, a neighbor who hunted big game in Africa said the British system called small bore anything below 30 caliber. Medium bore was 30 to 40 and big bore was any caliber over 40.
Click to expand...

that is the way I have always thought of it. It is a fine way to compare the bore but just because gun has a bigger bore does not mean its more powerful. The 50GI is 50 caliber but it is a pretty weak round compared to other handgun round even more so when you include rifle rounds.
 
8 mm and below is small bore. The German 8x57IS was the biggest of the cartridges allowed in "small bore" competitions. I guess since the competition rules have moved on the definition may have changed.

8 to 10 mm is medium bore. You will find a lot of reference to the 375 H&H as a "medium bore" round.

Over 10 mm is big bore.

In America small bore is now synonymous with rimfire, although I don't know how that developed. In some countries "fullbore" refers to a service rifle competition (in 308 Win).

Jimro
 
Yeah, this is an old topic but I am famous for searching and bringing them back.

BORE is the result of a measurement when manufacturing a barrel. Classifications can change pending what you are trying to accomplish. Do we include tanks and battleships?

So for general firearms discussions we seam to keep the cal. between the .17 HMR and the .50 cals. So why not do basic math. 17 thru 45 divided by however many categories and then a little bit of common sense. Small, Medium and Big....1-29, 30-39, 40-50. The power each cal can produce has nothing to do with the measurement of the bore!
 
How about a system that rates by recoil, instead of just bore size?
Examples,
.22 CB caps to .223 = No recoil.
.243 to .308 = medium recoil.
7mm Mag, 375 H&H or better = Kicks like a mule.
600 Nitro Express? = Hold onto your hat, this is going to be rough. :eek:
 
Caliber classifications

Caliber classifications: Another source has this system. Small bore would be less than 27 caliber. Medium bore would be between 27 and 336 caliber. The big bores are 375 upward. This is FYI. No dog in this race.
 
When we say "caliber" what we really mean is cartridge. Nobody would consider a lever action Henry chambered in .44 Magnum a "big bore" rifle, even though the bore is .429 in diameter. It's basically a deer rifle. It doesn't even kick that hard.
 
Quite a few people are just referring to bore diameter, when saying caliber. Doesn't Henry call their .44 a "Big Bore"?

Winchester named their revamped model 94 in .375 Win the 94 Big Bore.

In general big bore is applied to anything over .35 caliber, though some put the line at .37caliber. And it doesn't matter if its a powerful big bore, or not.

In pistols, .35s are considered medium, 40 and up is big bore.

Big bores can be deer rifle power level, or more, or in some cases, even less.
 
In the days of Davy Crockett, a .36 was considered a squirrel rifle.

Now when it comes to shotguns, a .410 is "small bore"

THIS.............is a big bore.
eGf5yeE.jpg
 
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small game calibers
deer calibers
American big game calibers
African big game calibers
Click to expand...

Best way to see it.

Since a 6mm round is rarely used on small game and mostly on medium game it fits into medium bore.

elk or moose aren't commonly hunted with anything bigger than a thirty caliber, thirty tops out medium.

The really big american game is rarely hunted with a .375 round or larger, so medium to large goes up from thirty to the .375. Big bore is anything that size or bigger than that.

I find it hard to slip the light weight large bore rifles in with the thumpers. someone's .44 magnum lever is big in bore size only.

Yep, I find bore size to be a vague question and it seems kind of unimportant. I think of the things by whether I would take them after a deer, squirrel, coyote, bear, bison, etc.
 
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