.45 Colt? .451 or .452?

Xfire68 · May 18, 2010, 10:16 PM

I will be loading up loads for a Judge and noticed that .45 colt may or may not shoot .451 but rather .452 in jacketed bullets? Do I have to stick to the limited .452 bullets or can the .451's be used safely?? Thanks for your expert help!

Lost Sheep · May 19, 2010, 03:45 AM

To be absolutely sure, you could slug your bore and measure your cylinder throats and the entry to your forcing cone.

The historical variations in various firearms chambered nominally for the 45 Colt have made for a great deal of confusion with projectile sizes.

Knowing that a .001" variation is not likely to be make-or-break critical, I would do what I have done and used .451 or .452 in jacketed and anything in cast lead from .451 to .454, but starting in the low pressure range first until I prove to myself that I am not generating dangerous conditions.

Excuse me now; I gotta go take my own advice and go put a micrometer on my gun.

Lost Sheep

Dannyl · May 19, 2010, 04:45 AM

Yeap,
Slugging is the right way to determine it.
However, IMO (had an issue many years ago with a barrel on a Browning), even such a small difference will result in higher pressures or very poor accuracy, depending whether your bullets are smaller or larger than the bore diameter.

So shooting bullets that are smaller than the bore will not be dangerous, But don't expect any decent accuracy.
Brgds,

Danny

zippy13 · May 19, 2010, 06:37 AM

Why guess?... Slugging a barrel is relatively easy.

HALIFAX · May 19, 2010, 11:08 AM

From what im reading the bullet diameter for a .45 colt is .454. Correct me if im wrong.

**Mal H** · May 19, 2010, 11:16 AM

For modern production .45 Colts, you're wrong. Revolvers such as the Vaquero, Cimarron, Rossi, etc. will usually take jacketed bullets in .451 and lead in .452. Older .45 Colts such as an SAA and other new and old models might be bored to take .454 lead. Lead bullet configurations with a cannelure and lube groove in .454" can usually be used in most .45 Colts without a problem.

As suggested any owner of a .45 Colt, more than any other caliber, should always slug the barrel to be sure of its diameter unless it is explicitly stated in the owners manual.

Xfire68 · May 19, 2010, 12:40 PM

Thanks for the info and tip on slugging the bore. Being new to revolvers and "older" calibers I need to know as much as I can before I start.

I have yet to buy dies to load the .45 Colt so I am not guessing on anything and want to be sure I order the right components to load them up right.

Dannyl · May 19, 2010, 03:29 PM

Good going, rather ask as many questions as you need, play it safe. (and off course read at least one reputable reloading manual)
Brgds,
Danny

Head-Space · May 19, 2010, 03:50 PM

Just for point of reference, a hair off your head is about 0.002". Hair off a beard, mustache is about 0.004". I was trimming cases the other day and the micrometer is reading, 2.4855" (between the lines). Then 2.485", then 2.486".

At thousandths and ten-thousandths, the measure you get is pretty much a function of how tight your turn the knob on the caliper.

May 18, 2010, 10:16 PM	#1
Xfire68 Senior Member Join Date: March 31, 2010 Location: Communist State of IL. Posts: 1,562	.45 Colt? .451 or .452? I will be loading up loads for a Judge and noticed that .45 colt may or may not shoot .451 but rather .452 in jacketed bullets? Do I have to stick to the limited .452 bullets or can the .451's be used safely?? Thanks for your expert help!

May 19, 2010, 03:45 AM	#2
Lost Sheep Senior Member Join Date: January 24, 2009 Location: Anchorage Alaska Posts: 3,341	Hey! It used to be .454" To be absolutely sure, you could slug your bore and measure your cylinder throats and the entry to your forcing cone. The historical variations in various firearms chambered nominally for the 45 Colt have made for a great deal of confusion with projectile sizes. Knowing that a .001" variation is not likely to be make-or-break critical, I would do what I have done and used .451 or .452 in jacketed and anything in cast lead from .451 to .454, but starting in the low pressure range first until I prove to myself that I am not generating dangerous conditions. Excuse me now; I gotta go take my own advice and go put a micrometer on my gun. Lost Sheep

May 19, 2010, 04:45 AM	#3
Dannyl Senior Member Join Date: April 20, 2009 Location: Cape Town - South Africa Posts: 627	Yeap, Slugging is the right way to determine it. However, IMO (had an issue many years ago with a barrel on a Browning), even such a small difference will result in higher pressures or very poor accuracy, depending whether your bullets are smaller or larger than the bore diameter. So shooting bullets that are smaller than the bore will not be dangerous, But don't expect any decent accuracy. Brgds, Danny Last edited by Dannyl; May 19, 2010 at 10:03 AM.

May 19, 2010, 06:37 AM	#4
zippy13 Senior Member Join Date: August 23, 2008 Location: SoCal Posts: 6,442	Why guess?... Slugging a barrel is relatively easy.

May 19, 2010, 11:08 AM	#5
HALIFAX Member Join Date: May 11, 2010 Location: Missouri Posts: 63	From what im reading the bullet diameter for a .45 colt is .454. Correct me if im wrong.

May 19, 2010, 11:16 AM	#6
Mal H Staff Join Date: March 20, 1999 Location: Somewhere in the woods of Northern Virginia Posts: 16,949	For modern production .45 Colts, you're wrong. Revolvers such as the Vaquero, Cimarron, Rossi, etc. will usually take jacketed bullets in .451 and lead in .452. Older .45 Colts such as an SAA and other new and old models might be bored to take .454 lead. Lead bullet configurations with a cannelure and lube groove in .454" can usually be used in most .45 Colts without a problem. As suggested any owner of a .45 Colt, more than any other caliber, should always slug the barrel to be sure of its diameter unless it is explicitly stated in the owners manual.

May 19, 2010, 12:40 PM	#7
Xfire68 Senior Member Join Date: March 31, 2010 Location: Communist State of IL. Posts: 1,562	Thanks for the info and tip on slugging the bore. Being new to revolvers and "older" calibers I need to know as much as I can before I start. I have yet to buy dies to load the .45 Colt so I am not guessing on anything and want to be sure I order the right components to load them up right.

May 19, 2010, 03:29 PM	#8
Dannyl Senior Member Join Date: April 20, 2009 Location: Cape Town - South Africa Posts: 627	Good going, rather ask as many questions as you need, play it safe. (and off course read at least one reputable reloading manual) Brgds, Danny

May 19, 2010, 03:50 PM	#9
Head-Space Junior member Join Date: May 14, 2010 Posts: 187	Just for point of reference, a hair off your head is about 0.002". Hair off a beard, mustache is about 0.004". I was trimming cases the other day and the micrometer is reading, 2.4855" (between the lines). Then 2.485", then 2.486". At thousandths and ten-thousandths, the measure you get is pretty much a function of how tight your turn the knob on the caliper.