What is the difference between .45 Colt and .45 ACP Bullets

Eric M. · May 19, 2007, 11:46 PM

OK--Here goes.
Boy, I'm setting myself up to sound stupid, but I will do it anyway.
I shoot 200gr LSWC .45ACP bullets. I get them from the only gun shop around that has them.
They have been out for about a month, so I figured that I would get a box of .45 Colt RNFP bullets.
I haven't reloaded them yet, but I can't figure that there would be any difference from the other bullets except shape.
I'm looking to start with 4.5gr of 231 powder and work my way up.
On my .45ACP loads, I use 4.8gr of 231.
I will definitely have to play with the OAL because they are shorter than the .45ACP LSWC.
Am I thinking correctly on this one, or am I way off base, and playing with fire.
I will wait for responses from you guys before proceeding with any reloading.
My thinking seems too easy on this one to not ask you guys where I am going wrong.

Thanks in advance for any advice.

Eric

oldcars · May 20, 2007, 12:20 AM

I think you should be ok, just watch the rim so it headspaces alright, and load a few to make sure they go up the ramp smoothly(if your shooting them in an auto) but then again I'm new to reloading as well so I don't know a whole lot about it. I am doing the opposite, loading acp bullets in a 45lc case!

Scorch · May 20, 2007, 02:35 AM

They're safe to load and fire. You may have some feeding issues depending on the profile of the bullet.

joneb · May 20, 2007, 02:38 AM

Erick, do these .45 colt bullets have a crimp groove ?

**Mal H** · May 20, 2007, 08:36 AM

Eric - what is the diameter of the .45 Colt bullets? Some .45 Colt lead bullets are sold in .454" size for use in certain revolvers. Lead bullets for .45 ACP are almost always .451" or, more commonly, .452". The larger bullet will work ok, but you have to be careful about pressure. Obviously, the larger bullet will cause a higher pressure and you should back off from your normal load a bit until you know the load is safe for your gun.

In general, I think you're good to go.

Eric M. · May 20, 2007, 09:15 AM

The diameter is .452", and yes, there is a crimp groove on them which I am planning to ignore.
I always load on the low side, and all of my accuracy loads pretty much stay on the low end.
Sorry, but I forgot to tell you guys that I will be using both of my 1911's with this load.

Eric

MADISON · May 20, 2007, 10:06 AM

Before WW-II the .45 Long Colt diameter was .454.
After WW-II the diameter is .452 for both calibers.

joneb · May 20, 2007, 12:28 PM

I would try seating one to match the load density of the acp bullet, then check to see if the round will chamber properly in the barrel, should look something like this;
reloading 010.jpg if the round sticks up past the end of the barrel shroud you'll need to seat deeper, which will increase the pressure.

TEDDY · May 20, 2007, 02:02 PM

looks like your a fine canidate for cast bullets.if you cast your own you dont have to rely on ANY shortage.the Lee set up can be done for about $100.depending on source.MIDSOUTHSHOOTERS.COM best prices.I am thaking a rest from casting at this moment.

Eric M. · May 20, 2007, 08:59 PM

I just came from the range and fired 10 rounds at 4.8gr of 231 oal of 2.115", and 10 rounds at 5.2gr of 231 oal of 2.115"
All of the loads fed just fine, but enough stuff hit the air that I think that even the 5.2gr was too light of a load.
Tomorrow I will load some 5.4gr, and 5.6gr to see if it shoots cleaner and more accurate.
The recoil was minimal but I was hit in the face with some unburnt powder.
I think that the oal of 2.115" if fine. No feeding or ejection problems, and the case stops just a few thousandths short of the crimp groove.
I can also try some Clays powder also.

Teddy, you are right about me starting to cast. I think that it is about time to start thinking about it.

Eric

**Unclenick** · May 20, 2007, 10:32 PM

In the stubby .45 ACP case, what matters is seating depth. That cartridge is very sensitive to seating depth for two reasons. One is that it takes very little change in how deep the base goes into the case to raise pressure significantly. For example, 5.0 grains of Bullseye under the 230 grain FMJ round nose bullet (a standard mimic load for government hardball) seated to 1.275" will produce only about 16,200 PSI. If you seat it to 1.19" COL, as the Alliant web site erroneously shows, you will get about 25,000 PSI; well above the +P upper limit of 23,000 PSI. (I have written Alliant on this point but received no reply to date, so don't believe what you see there on COL; I own a pressure test barrel for .45 ACP and have been able to validate what I am saying here.)

The second issue is that most cases, especially mil spec, but excepting Remington cases with their thin upper case web brass, thicken in the web below normal hardball seating depth. Some .45 Colt bullets try to seat deeper, which not only raises pressure but bulges the thicker web brass out until it won't chamber. In the 200 grain range that should not be a problem. Just double-check that your base isn't going in any deeper than the those of the 200 grains SWC's you normally use, and you will be fine. Indeed, the loads you mention are below normal military pressure levels with 230 grain pumpkin ball, so as long as the bullet base goes into the case no deeper than 0.267", you will be fine.

Nick

MADISON · May 24, 2007, 09:44 AM

If your .45 Long Colt was made before WW-II the diameter is .454.
After WW-II both .45 Long Colt and .45 ACP are .452 diameter.

**Mal H** · May 24, 2007, 03:47 PM

MADISON - you're repeating yourself.

(post 7)

Actually that isn't totally true. You can buy bullets for .45 Colt in either .452 or .454. It all depends on which handgun you are reloading for. Meister Bullets, for example, has them in both sizes.

May 19, 2007, 11:46 PM	#1
Eric M. Senior Member Join Date: January 26, 2007 Location: Forest Lake, Minnesota Posts: 307	What is the difference between .45 Colt and .45 ACP Bullets OK--Here goes. Boy, I'm setting myself up to sound stupid, but I will do it anyway. I shoot 200gr LSWC .45ACP bullets. I get them from the only gun shop around that has them. They have been out for about a month, so I figured that I would get a box of .45 Colt RNFP bullets. I haven't reloaded them yet, but I can't figure that there would be any difference from the other bullets except shape. I'm looking to start with 4.5gr of 231 powder and work my way up. On my .45ACP loads, I use 4.8gr of 231. I will definitely have to play with the OAL because they are shorter than the .45ACP LSWC. Am I thinking correctly on this one, or am I way off base, and playing with fire. I will wait for responses from you guys before proceeding with any reloading. My thinking seems too easy on this one to not ask you guys where I am going wrong. Thanks in advance for any advice. Eric __________________ NRA Chief Range Safety Officer NRA Pistol Instructor NRA Life Member DNR Certified Firearms Safety Instructor 37 yrs

May 20, 2007, 02:35 AM	#3
Scorch Senior Member Join Date: February 13, 2006 Location: Washington state Posts: 15,248	They're safe to load and fire. You may have some feeding issues depending on the profile of the bullet. __________________ Never try to educate someone who resists knowledge at all costs. But what do I know? Summit Arms Services

May 20, 2007, 09:15 AM	#6
Eric M. Senior Member Join Date: January 26, 2007 Location: Forest Lake, Minnesota Posts: 307	The diameter is .452", and yes, there is a crimp groove on them which I am planning to ignore. I always load on the low side, and all of my accuracy loads pretty much stay on the low end. Sorry, but I forgot to tell you guys that I will be using both of my 1911's with this load. Eric __________________ NRA Chief Range Safety Officer NRA Pistol Instructor NRA Life Member DNR Certified Firearms Safety Instructor 37 yrs

May 20, 2007, 10:06 AM	#7
MADISON Senior Member Join Date: January 1, 2000 Location: Roanoke, Virginia Posts: 2,678	45LC and 45 ACP bullets Before WW-II the .45 Long Colt diameter was .454. After WW-II the diameter is .452 for both calibers.

May 20, 2007, 02:02 PM	#9
TEDDY Junior member Join Date: December 10, 2006 Location: MANNING SC Posts: 837	45 acp looks like your a fine canidate for cast bullets.if you cast your own you dont have to rely on ANY shortage.the Lee set up can be done for about $100.depending on source.MIDSOUTHSHOOTERS.COM best prices.I am thaking a rest from casting at this moment.

May 20, 2007, 12:20 AM	#2
oldcars Senior Member Join Date: March 13, 2007 Posts: 375	I think you should be ok, just watch the rim so it headspaces alright, and load a few to make sure they go up the ramp smoothly(if your shooting them in an auto) but then again I'm new to reloading as well so I don't know a whole lot about it. I am doing the opposite, loading acp bullets in a 45lc case!

May 20, 2007, 02:38 AM	#4
joneb Senior Member Join Date: December 10, 2005 Location: Central , OR Posts: 1,888	Erick, do these .45 colt bullets have a crimp groove ?

May 20, 2007, 08:36 AM	#5
Mal H Staff Join Date: March 20, 1999 Location: Somewhere in the woods of Northern Virginia Posts: 16,955	Eric - what is the diameter of the .45 Colt bullets? Some .45 Colt lead bullets are sold in .454" size for use in certain revolvers. Lead bullets for .45 ACP are almost always .451" or, more commonly, .452". The larger bullet will work ok, but you have to be careful about pressure. Obviously, the larger bullet will cause a higher pressure and you should back off from your normal load a bit until you know the load is safe for your gun. In general, I think you're good to go.

May 20, 2007, 12:28 PM	#8
joneb Senior Member Join Date: December 10, 2005 Location: Central , OR Posts: 1,888	I would try seating one to match the load density of the acp bullet, then check to see if the round will chamber properly in the barrel, should look something like this; reloading 010.jpg if the round sticks up past the end of the barrel shroud you'll need to seat deeper, which will increase the pressure.

May 20, 2007, 08:59 PM	#10
Eric M. Senior Member Join Date: January 26, 2007 Location: Forest Lake, Minnesota Posts: 307	I just came from the range and fired 10 rounds at 4.8gr of 231 oal of 2.115", and 10 rounds at 5.2gr of 231 oal of 2.115" All of the loads fed just fine, but enough stuff hit the air that I think that even the 5.2gr was too light of a load. Tomorrow I will load some 5.4gr, and 5.6gr to see if it shoots cleaner and more accurate. The recoil was minimal but I was hit in the face with some unburnt powder. I think that the oal of 2.115" if fine. No feeding or ejection problems, and the case stops just a few thousandths short of the crimp groove. I can also try some Clays powder also. Teddy, you are right about me starting to cast. I think that it is about time to start thinking about it. Eric __________________ NRA Chief Range Safety Officer NRA Pistol Instructor NRA Life Member DNR Certified Firearms Safety Instructor 37 yrs

May 20, 2007, 10:32 PM	#11
Unclenick Staff Join Date: March 4, 2005 Location: Ohio Posts: 21,063	In the stubby .45 ACP case, what matters is seating depth. That cartridge is very sensitive to seating depth for two reasons. One is that it takes very little change in how deep the base goes into the case to raise pressure significantly. For example, 5.0 grains of Bullseye under the 230 grain FMJ round nose bullet (a standard mimic load for government hardball) seated to 1.275" will produce only about 16,200 PSI. If you seat it to 1.19" COL, as the Alliant web site erroneously shows, you will get about 25,000 PSI; well above the +P upper limit of 23,000 PSI. (I have written Alliant on this point but received no reply to date, so don't believe what you see there on COL; I own a pressure test barrel for .45 ACP and have been able to validate what I am saying here.) The second issue is that most cases, especially mil spec, but excepting Remington cases with their thin upper case web brass, thicken in the web below normal hardball seating depth. Some .45 Colt bullets try to seat deeper, which not only raises pressure but bulges the thicker web brass out until it won't chamber. In the 200 grain range that should not be a problem. Just double-check that your base isn't going in any deeper than the those of the 200 grains SWC's you normally use, and you will be fine. Indeed, the loads you mention are below normal military pressure levels with 230 grain pumpkin ball, so as long as the bullet base goes into the case no deeper than 0.267", you will be fine. Nick __________________ Gunsite Orange Hat Family Member CMP Certified GSM Master Instructor NRA Certified Rifle Instructor NRA Benefactor Member and Golden Eagle

May 24, 2007, 09:44 AM	#12
MADISON Senior Member Join Date: January 1, 2000 Location: Roanoke, Virginia Posts: 2,678	.45 Long Colt & .45 ACP bullet sizes If your .45 Long Colt was made before WW-II the diameter is .454. After WW-II both .45 Long Colt and .45 ACP are .452 diameter.

May 24, 2007, 03:47 PM	#13
Mal H Staff Join Date: March 20, 1999 Location: Somewhere in the woods of Northern Virginia Posts: 16,955	MADISON - you're repeating yourself. (post 7) Actually that isn't totally true. You can buy bullets for .45 Colt in either .452 or .454. It all depends on which handgun you are reloading for. Meister Bullets, for example, has them in both sizes.