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View Full Version : Bore/groove diameters for .44 and .45 cal leverguns?



DougGuy
01-08-2014, 11:28 PM
I am probably going to get a levergun in .44 Magnum or .45 Colt but would like to ask about bore diameters for popular models. First off, I like the '92 and it's likely gonna be either a '92 or a Henry Big Boy. I have read where the Marlin has varied bore diameter of .430" or .432" depending on what kind of rifling, and now I am reading where the Rossi has a .454" groove diameter in .45 Colt and that they prefer .454" boolits so this is somewhat confusing as I would like to use the same .432" and .452" cast boolits and loads that I use in my Ruger pistols of those calibers.

What are the nominal groove diameters for Rossi, Winchester, Marlin, and Henry in both .44 and .45 caliber?

Outpost75
01-09-2014, 12:06 AM
You really need to cast chambers and slug individual guns because they vary. However, more important than bore and groove diameter is the diameter of the unrifled portion of the ball seat or forcing cone, ahead of the case mouth, before the rifling starts. In a SAAMI .45 Colt chamber this can be as large ss. 458 and in a minimum chamber will be .455".

I shoot as-cast and unsized bullets in .45 Colt rifles, and size to ball-end cylinder throat diameter in revolvers, .452" for Rugers and. 455" in pre WW2 Colts.

MtGun44
01-09-2014, 02:19 AM
LOL! No way to know. Have to check each gun, they vary,
which is why this is a puzzle.

Bill

Lonegun1894
01-09-2014, 03:17 AM
Not to be a smartalec, but I would get whichever gun you like, and then figure out what IT likes after measuring it. You MAY get lucky, but you may not, regardless of brand or model. Manufacturers have what they call an acceptable range of land/groove measurements, so the first rifle to be bored and rifled will have a larger bore than the second, or last for that matter, because the cutter gets worn down slightly as it cuts. I hate to say it, but it is a crapshoot. They start with a new cutter, and end up with a large bore, and then the bores get smaller as the cutters wears and gets smaller, and all these rifles will be within that acceptable range, but they will not be identical. And then, when the cutter wears to the limit of it's useful life, they get a new cutter, and get the larger bores again. So you see, short of finding a particular rifle and slugging it, no one has any way of being able to tell you what it will slug, other than that it will be "between .uvw" and .xyz" for caliber x". Does that make sense? This is why I say find a rifle you like instead of buying one that may be a second or third choice just because someone guessed that they may be the size you need, or maybe that their's is the size you want so you may get lucky too, or maybe not get lucky.

Nobade
01-09-2014, 08:38 AM
My Marlin 1894CB 45 Colt uses .458" boolits and my 1894 44 Mag uses .434" boolits if that tells you anything...

Like previous posters said, just feed them what they want for best results.

-Nobade

snaketail
01-09-2014, 10:03 AM
Its a lot like figuring out what the cat like to eat. You may have to try a couple of times, but once you get it right - stay with the best results.

M

searcher4851
01-09-2014, 12:07 PM
Lonegun pretty much summed it up. Your chances are probably going to be better in the 44 mag. 45 Colt leverguns just seem to be more inclined to the .454 diameter bullets in my experience.

Maximumbob54
01-09-2014, 12:20 PM
My Rossi does fine with them sized at .430".

DougGuy
01-09-2014, 01:35 PM
Well that all makes sense, so I guess it's the luck of the draw on what fodder it will like.. Thanks fellas, looks like I got to take my chances and just roll with it.

W.R.Buchanan
01-09-2014, 08:23 PM
I asked this question of Marlin CS when I first got my 1894 CB as the first rounds thru the gun went sideways thru the target at 50 feet.

I measured the groove dia and it was .431 so I asked what happened to .429 which is what all of my previous Revolvers had been since day one.

The answer I got was .431+/- .002. is SAAMI spec for .44 magnum rifles. This is looser due to the higher pressures that a rifle barrel would generate as opposed to revolvers which are generally .429 but have that nice pressure relief valve between the cylinder and the barrel.

As stated several times above there is no real way to predict what it is until you measure it.

There are variations in manufacturing.

Randy

Buckshot
01-13-2014, 03:55 AM
http://www.fototime.com/7848272124A4E8F/standard.jpg

My Rossi M92 rifle has a bore/groove of .446" - .450". Shallow grooves so I treat it like a Micro-Groove bbl. Cast'em hard and fat. The chamber will swallow a Lee 457-340-F sized to .456" but the 32" twist is a tad slow.

http://www.fototime.com/745969169444B08/standard.jpg

Have a Miroku M92 also in 45 Colt. It's bore and groove is .444" x .452" with the pistol twist of 16". It's chamber will swallow a round loaded with a .454" sized slug.

..............Buckshot

charger 1
01-16-2014, 06:32 PM
LOL! No way to know. Have to check each gun, they vary,
which is why this is a puzzle.

Bill

Puzzle combined with some can complicate the making of jello