Does .44 cal = .45 cal?

[whitfang]

Why is it sounding like .44 and .45 caliber revolvers are "the same?"  A couple of you have made that comment, and I see ammo for a .44 that looks like it should be shot in a .45.

If a Ruger Old Army .45 uses .451, .454, or .457 lead balls,  can you use those balls in a .44 cal  revolver?  Does the excess just make for hard loading and get shaved off?

But you probably don't want to use .44 cal balls in a .45, because it would be too loose and not very accurate?   :?

[Flint]

Cap & Ball 44 caliber revolvers are 44 caliber BEFORE the barrel is rifled.  The rifled barrel takes a 451 to 457 ball depending on the maker.  So, all the 44 caliber conversion cylinders are chambered in 45 Colt (Long Colt) as that bullet will fit the Remingtons, Colts and Ruger Old Armies.  In the same way, the 36 Caliber Navy was 36 caliber before rifling, and grooves out to 375, the diameter of the round ball.  A modern 38 bore is 357 diameter, which is the diameter of the bore minus the thickness of the brass....  The Brass is the diameter of the original 375 roundball.  The 44 Colt was a heel type bullet which fit the 45 bore, and later 44 bullets, like the 44 Russian, Special and Magnum were sized down to 44 caliber to fit inside the cartridge case, and the bore reduced to .431 to match...So modern 44s are really 43 caliber and modern 38s are really 36 caliber...  fun eh?

[Chris]

Good stuff but ....WHEW!    :shock:  It will take me a while to put all of that in the old memory bank!

Waaaay too many numbers for the NorCal redneck to understand. Not your fault...too many concussions playing ball in my youth!  

...Chris  

[whitfang]

You're right about too many numbers.   :eek:

Let me ask a simple question.  The Ruger manual says to shoot .457 lead balls in an Old Army.

If I buy a .44 cal revolver later, can I shoot the .457 lead balls in it?

Answer 'YES' or 'NO'.  

[Flint]

Yes...............

[The Shrink]

Whitefang

If you get another maker's .44 C&B you will notice that the larger ball loads somewhat harder and you get a larger ring of lead off the ball.  This is not bad, as it increases the bearing surface of the ball on the rifling.  The only potential problem is stress on the loading mechanism.  If that mechanism is somewhat fragile, as in my LeMat or as I believe is true of the Starr, you may want to go to a smaller ball.  If you get an 1860 Colt you'll have no problem, and the same is true with the Remington or the Rogers & Spencer.

[unspellable]

Caliber = land diameter = bore diameter = diameter before rifling, ie. the diameter the barrel was bored out to.

Groove diameter = groove diameter.

Hence a 44 caliber gun taking a 45 diameter bullet would be expected to have a land to land diameter of 0.440 inch and a groove to groove diameter of 0.450 inch.  (Not that actual real worl designations are noted for religiously sticking to the rules.)

People frequently get these terms confused.

Except when dealing with smooth bored muzzle loading cannons where the bore is specified as the weight of an iron ball sized to fit.  Four pounder, eight pounder etc.  With the cannon, caliber is the length of the bore divided by its diameter.  So a 30 caliber cannon has a bore 30 times as long as its diameter and we havn't said anything about the bore size.

[whitfang]

OK, good explanation.  I think I understand.  
But if everything is standard, shouldn't the following be true?

Bore diameter .44,  Groove diameter .45,  Bullet Range: .451 to .457

Bore diameter .45,  Groove diameter .46,  Bullet Range: .461 to .467

[unspellable]

In five words or less, everything isn't standard.  There is no "standard" difference between caliber and groove size.  Gun and Cartridge nomencalture is famous for not following the standard such as it is.  You will go nuts trying to find ryme and reason.

Examples:

30-40 Krag:  0.300 caliber   0.308 groove
30-06:          0.300 caliber   0.308 groove
308:             0.300 caliber   0.308 groove
307:             0.300 caliber   0.308 groove

38 Special:            0.357 groove
357 Magnum:        0.357 groove
360 Dan Wesson:   0.357 groove
357 SIG:               0.355 groove

45-70                   0.458 groove
458 Winchester     0.458 groove
45 Colt                 0.454 pre WWII, 0.451 post WWII
454 Casull:           0.451 groove

44 Magnum          0.429 groove
445 Super Mag     0.429 groove

41 Mag                0.410 groove
414 Super Mag     0.410 groove

32 Special            0.320 groove
32-20                   0.311 groove in most
                           0.308 groove in Contender

Most muzzle loading rifles and single shot pistols are specified by groove diameter while most muzzle loading revovlers are specified by caliber.

Not much rhyme or reason is there?

[Flint]

Several things will drive the groove depth, the powder expected, the bullet construction expected, and the number of lands and grooves.  

Black powder arms have deeper rifling, as a deeper groove allows more fouling before the grooves are filled up, and the ball is expected to be pure lead or soft alloy and needs deeper rifling to prevent stripping the ball.

Jacketed bullets with smokeless powder require shallower rifling as the fouling is minimal and the bullet is very much harder than lead.

Mocrogroove rifling is even shallower as there are so many more lands and grooves used to make up for depth.

Most smokeless rifling seems to be .003 to .006 deep, and black powder rifling is usually double that and even more.

[Ramrod]

whitfang, maybe the thing that is confusing you is that the Ruger is a modern weapon, so it has the modern designation, .45 cal. This is the same as what the oldtimers called .44 in a cap and ball gun. Flint's first post pretty much sums it up. The names and sizes changed slowly over time as common folk caught up with technology.

[whitfang]

OK, got it.  Thanks.