.45acp - Page 2

Rico567 · December 10, 2006, 07:28 AM

What various people have been trying to explain in this thread is that there are a great many things that affect a single measurement, like velocity.

There is the gun itself- as someone pointed out, Speer is different from many other commercial publishers of reloading data, in that their testing is done with a particular firearm, not a universal receiver. Once they've picked the firearm, if you have a different one there's a good chance of variation. Barrel diameter, the leade (the part of the barrel between the cartridge an the rifling proper), etc., all can cause variation.

Cases- cases can have different capacities, which is guaranteed to cause different pressures. Also, as cases grow with repeated firings, excessive case length can jump pressures.

Primers- Primers may generate hotter or cooler flames, thus changing the speed of powder ignition.

Powder- Powders not only have different burning rates, but those rates can change from lot to lot of powder. Also, the temperature can greatly affect burning rate. Some powders, like BLC-2, are notoriously affected by cold temperatures.

Bullets- Big differences among lead, plated, jacketed bullets. Lot to lot variation may also occur here. The composition of the lead alloy, the thickness of a jacket....all can affect pressures /velocity.

This may seem like quite a lot, but I have undoubtedly overlooked some things. It's one of the things that make our mutual pastime so rewarding and fascinating. Take the earlier advice given: always use the low figure (starting) given for powder charges, and work up gradually, watching for pressure signs as described in the literature.

C17A · December 10, 2006, 05:53 PM

To augment the advice given, and echo comments on safety:

Trying to get the last bit of velocity and energy out of the 45ACP and find the hottest load will get you the nickname "Ol' One-Eye" or "Ol' Two Fingers." Don't try to make a magnum out of the 45ACP--if you want one, buy a 454 Casull or something like that. The 45ACP was an attempt to get performance similar to the black-powder loaded 45 Colt Peacemaker in an automatic pistol with smokeless powder. One that succeeded brilliantly, IMO. It's not a magnum, and cannot be made into one.

As a reloader, I am an "assembler," not an "experimenter." I fully research, check, re-check, and check again, that I am loading the right power in the right case with the right bullet, with the right primer to set it off. There are those who use cut-down and reamed 308 Winchester cases to make a stronger case, to make hot 45ACP loads so they can get way over 1,000 fps with 250-gr bullets. The Colt 45 will not hold up to such loads, even with shock buffers. Colt 45 autos greatly benefit from use of a shock buffer to keep frame battering to a minimum.

My own load for 45ACP is a light-midrange load for target shooting with Bullseye powder, Winchester WLP primers, with cast Lyman 452460 bullets, in a Gold Cup set up for same.

XD-Guy · December 11, 2006, 10:34 AM

I also have 7.2 for a max load

bertos · December 11, 2006, 08:03 PM

xd-guy was that 7.2 from the speer manual?

Ultima-Ratio · December 11, 2006, 08:36 PM

Trying to get the last bit of velocity and energy out of the 45ACP and find the hottest load will get you the nickname "Ol' One-Eye" or "Ol' Two Fingers." Don't try to make a magnum out of the 45ACP--if you want one, buy a 454 Casull or something like that. The 45ACP was an attempt to get performance similar to the black-powder loaded 45 Colt Peacemaker in an automatic pistol with smokeless powder. One that succeeded brilliantly, IMO. It's not a magnum, and cannot be made into one.
Ummmm?
SO ya ever hear of the .451 Detonics, .45 Super, 460 Rowland or even Plus P???
BTW, it's chamber support not brass thickness to eliminate "Ka-Booms" and Superface!
Either war as to the original question, buy a chronograph or borrow one, manuals are rarely on the money for velocities.
FYI, when brass is properly supported (at least up to but not including the extractor groove) the brass ain't gonna fail!
Times have changed since the olde 38-45 Clerke and the early .45 Supers loaded with Alcan

Ken - Oh · December 15, 2006, 06:05 PM

The other thing to consider is the bullet height and the seating depth/COL.

Two different 230 gr FMJ bullets may have different heights due to their shape. It takes more length to get get 230 grains into a narrow bullet head than into a fat one. That means that the bullet has to sit deeper for the same COL. A deeper seated bullet means higher pressure.

Of course, if one manual uses one COL and a different manual uses a larger COL, that will change the pressure.

The eyeopener for me is the Lyman manual where they have loads for two similar SWC bullets. The starting load for one is at the max load for the other! This is in the same manual, on the same page!

Of course, how tight the bullet is crimped will also affect the pressure.

Ken

December 10, 2006, 07:28 AM	#26
Rico567 Senior Member Join Date: October 19, 2005 Posts: 162	What various people have been trying to explain in this thread is that there are a great many things that affect a single measurement, like velocity. There is the gun itself- as someone pointed out, Speer is different from many other commercial publishers of reloading data, in that their testing is done with a particular firearm, not a universal receiver. Once they've picked the firearm, if you have a different one there's a good chance of variation. Barrel diameter, the leade (the part of the barrel between the cartridge an the rifling proper), etc., all can cause variation. Cases- cases can have different capacities, which is guaranteed to cause different pressures. Also, as cases grow with repeated firings, excessive case length can jump pressures. Primers- Primers may generate hotter or cooler flames, thus changing the speed of powder ignition. Powder- Powders not only have different burning rates, but those rates can change from lot to lot of powder. Also, the temperature can greatly affect burning rate. Some powders, like BLC-2, are notoriously affected by cold temperatures. Bullets- Big differences among lead, plated, jacketed bullets. Lot to lot variation may also occur here. The composition of the lead alloy, the thickness of a jacket....all can affect pressures /velocity. This may seem like quite a lot, but I have undoubtedly overlooked some things. It's one of the things that make our mutual pastime so rewarding and fascinating. Take the earlier advice given: always use the low figure (starting) given for powder charges, and work up gradually, watching for pressure signs as described in the literature. __________________ "Dear reader, suppose you are a member of Congress. Now, further suppose you are an idiot. But I repeat myself." - Mark Twain

December 11, 2006, 08:36 PM	#30
Ultima-Ratio Junior member Join Date: May 18, 2004 Location: Anchorage Alaska Posts: 227	Ah The Conservatives! Trying to get the last bit of velocity and energy out of the 45ACP and find the hottest load will get you the nickname "Ol' One-Eye" or "Ol' Two Fingers." Don't try to make a magnum out of the 45ACP--if you want one, buy a 454 Casull or something like that. The 45ACP was an attempt to get performance similar to the black-powder loaded 45 Colt Peacemaker in an automatic pistol with smokeless powder. One that succeeded brilliantly, IMO. It's not a magnum, and cannot be made into one. Ummmm? SO ya ever hear of the .451 Detonics, .45 Super, 460 Rowland or even Plus P??? BTW, it's chamber support not brass thickness to eliminate "Ka-Booms" and Superface! Either war as to the original question, buy a chronograph or borrow one, manuals are rarely on the money for velocities. FYI, when brass is properly supported (at least up to but not including the extractor groove) the brass ain't gonna fail! Times have changed since the olde 38-45 Clerke and the early .45 Supers loaded with Alcan

December 10, 2006, 05:53 PM	#27
C17A Member Join Date: November 23, 2006 Location: Southern California Posts: 37	To augment the advice given, and echo comments on safety: Trying to get the last bit of velocity and energy out of the 45ACP and find the hottest load will get you the nickname "Ol' One-Eye" or "Ol' Two Fingers." Don't try to make a magnum out of the 45ACP--if you want one, buy a 454 Casull or something like that. The 45ACP was an attempt to get performance similar to the black-powder loaded 45 Colt Peacemaker in an automatic pistol with smokeless powder. One that succeeded brilliantly, IMO. It's not a magnum, and cannot be made into one. As a reloader, I am an "assembler," not an "experimenter." I fully research, check, re-check, and check again, that I am loading the right power in the right case with the right bullet, with the right primer to set it off. There are those who use cut-down and reamed 308 Winchester cases to make a stronger case, to make hot 45ACP loads so they can get way over 1,000 fps with 250-gr bullets. The Colt 45 will not hold up to such loads, even with shock buffers. Colt 45 autos greatly benefit from use of a shock buffer to keep frame battering to a minimum. My own load for 45ACP is a light-midrange load for target shooting with Bullseye powder, Winchester WLP primers, with cast Lyman 452460 bullets, in a Gold Cup set up for same.

December 11, 2006, 10:34 AM	#28
XD-Guy Senior Member Join Date: November 20, 2006 Posts: 102	I also have 7.2 for a max load

December 11, 2006, 08:03 PM	#29
bertos Junior Member Join Date: October 28, 2006 Posts: 10	xd-guy was that 7.2 from the speer manual?

December 15, 2006, 06:05 PM	#31
Ken - Oh Senior Member Join Date: August 2, 2006 Posts: 280	The other thing to consider is the bullet height and the seating depth/COL. Two different 230 gr FMJ bullets may have different heights due to their shape. It takes more length to get get 230 grains into a narrow bullet head than into a fat one. That means that the bullet has to sit deeper for the same COL. A deeper seated bullet means higher pressure. Of course, if one manual uses one COL and a different manual uses a larger COL, that will change the pressure. The eyeopener for me is the Lyman manual where they have loads for two similar SWC bullets. The starting load for one is at the max load for the other! This is in the same manual, on the same page! Of course, how tight the bullet is crimped will also affect the pressure. Ken