I was looking at a ballistics chart the other day. For some of the really big african rounds, I was seeing muzzle energy that approached or exceeded 10,000 ft lbs.

Which leads me to ask, "What is the cut off between a rifle and a cannon?" Yes, I know you could define it by saying, "Anything that is not in a brass cartridge, is not a rifle round." But considering some of the massive rounds that have been used over years, my question still stands.

On a recent thread, it was discussed about how many rounds can be fired before a headache developed. Certainly sounded like a mild concussion to me. Something I would expect when firing a cannon.

Pete

I believe cannons are defined as having a 1" or larger bore, which none of the sporting rifles do.

I think a more realistic criteria is can one carry and fire the weapon offhand practically. This excludes the 50 BMG's due to their weight, but even a 14 pound T-rex or Overkill can be carried and fired whithout much more effort than any other sporting rifle, and are certainly more adept then the sniper rifles topped with 50+mm objective scopes.

Some of us simply enjoy shooting the big stuff, and while you won't burn through several hundred rounds in an afternoon, the guns are shootable if you want to shoot them.

A 20mm cannon has a bore smaller than one inch.

The military usually defines a rifle as being shoulder-fired and man-portable. Cannons are fixed to a mount of some sort.

Fixed weapons that fire rifle cartridges usually have the term "gun" somewhere in the name. Machinegun, Chain-gun, Co-axial gun, etc.

QW,
I think you are refering to useability rather than some definition of bore diameter as a cut off for a sporting arm.

The 4 bore is darn near an inch, for what it's worth.

IMNSHO to be a hunting gun it MUST BE *for me and and me alone*
1: Light enough to be carried for the circumstance of the game being hunted (5 to 12lbs)
2: Powerful enough to dispatch ANY of the potential beasts one might run into while in that particular field.. That is, You won't see me in Tanzania Swamps with a 708.... but you MIGHT find me on an alaskan moose hunt with a 500 jeffe. While a 300 wizmagsuper might take a lion/buff/bear, I would GREATLY prefer a 375 or 416 to make sure it was a ONE ROUND argument.
3: <to the shooter> Recoil and blast MUST be tolerable from the stand point of a follow on shot

and these are the SHOULDS
1: Should NOT have a muzzle brake (my preference)
2: SHOULD fit the shooter
3: SHould shoot tuned ammo
4: Only the "best" bullets should be shot at game...

Have a carried a 50 BMG shortie and stalked feral hogs... YEP!!! all 19.5# of that tank braked scoped SINGLE SHOT monster.... it was a stunt.

Have a taken small game with a 416... yep.....

just me rambling
jeffe

Those are EASY

Pete,

I don't think there is any real definite line in the sand as it will vary for different people.

However, if we look at useage then the cut off point is probably around the 50 BMG size. I say 50 BMG as that seems to be the biggest cartridge that has a fair degree of use and companies like McMillan and Prairie Gun Works and others make actions for the 50 BMG.

For me personally my interest drops right off if the cartridge can't be used on actions like M70, Mauser, CZ, Weatherby etc.

A similar situation is how do you define a "varmint cartridge". For many the varmint cartridge ends with the 6mm or 25 bore and for others the varmint cartridge is something like the 30/378, 338/378 and 50 BMG.

Mike

Though not a metalic cartridge case, many of the "4 bores" were actually 3 bores and the same described guns where also discribed as 2 bores but were not. I think a 3 bore might be over 1" ? Anyone done the math?
I guess many people would not see a limit, but I oftan look at it as physical human limitations of gun weight (while hunting) and recoil WHITHOUT a muzzle brake. That would probably set even the most seasoned at a 3-4 bore.
Just my opinion

A true 4 bore has a bore diameter of 1.04".

Axel

The specific gravity of lead is 11.34

The volume of a 1" diameter ball is 8.58 cc

That ball has a mass of 97.3 g or 0.214 lb.

So a 1" gun is actually about a 5-bore.

A 1/4 lb. lead ball is 1.053" in diameter, so a 4-bore is a little bigger than a 1" gun.

I thought those big old 4-bore elephant guns were smoothbore (not rifled).

H. C.

(I guess Todd beat me to it while I was messing with me Merck Index and calculator)

[ 06-07-2003, 05:41: Message edited by: HenryC470 ]

It becomes a cannon, when Overkill discovers it.

Bore size sometimes indicated a lesser bore size by one.

John shorb has followed this with his 4 bore rifled muzzleloader- .935" 1400 grain ball (from memory) which is 5 bore.
They varied quite a bit with loads and case length and later were rifled.
The 2 bore was the real smoothbore.

Pete,
'Shoulder fired' is my limit for real rifles.

This would include up to all nitro 585's, 620's, the 700 nitro and maybe the 4 bore, although the added term 'carryable' would keep power levels for the bigger stuff down, and disqualify the 4 bore by todays standards.

Seems 10,000ftlbs is about the most people subject themselves to hunting with the biggest rifles,to keep the rifle at 15lbs or so with brake.

And usually much less

Although some of the calibres can go a few thousand higher.

Above that are 'ground fired' etc or stunts as Jeffe said.
-The 50BMG in full length form, disqualified by barrel length even though recoil may be overlapped by some of the shoulder fired rifles.
-Its wildcats, getting heavier each step, or with similar length barrels, and then other military hardware etc.

I didn't include normal calibres in target, tact , benchrest or other specialised rifles as cannons.

The 4 bore historically has been the absolute limit for a shoulder fired hunting firearm withstood for any decent period of a career.
Maximum levels from a 24lb firearm(9000ftlbs +)generating 150ftlbs of recoil energy with projectiles up to 2000 grains.

Note, these were the toughest guys, usually with the help of gunbearers, in an age when they had no choice but put up with such oversized inneffiecient technology.

And a lot of them disliked it too.

The 2 bore was not really 'withstood' since it caused head injuries to at least one notable hunter from single firings.

Karl.

[ 06-07-2003, 17:59: Message edited by: Karl ]

Where the stopping point comes in with the big bores is when the big bore boys finally get to Africa and start packing that 13 lb. monster 505 10 miles a day in 90 degree or hotter weather or at least that was the case with me, suddenly I was shooting 9.3x62's in the 7 Lb. class and finally settled on 9 to 9.5 lbs in 416 and 404..Went from one extreme to the other..

Besides, believe it or not, I have never seen a lot of difference in killing power once you get to 416 and beyond that, albeit there is probably some there no doubt, but I have never needed it...