So much for Sweeney's "myths, lies and fallacies" re: the 1911. Moving on, this time the reference being "Hatcher's Notebook", the iconic book by Major General Julian S. Hatcher, Chief of the Machine Gun And Small Arms Section, Engineering Division, Ordnance during WWI, OIC Frankford Small Arms Ammunition Plant, head Honcho at Springfield Armory, author of several books on small arms etc., etc. Suffice it to say that Hatcher was considered an expert in all aspects of small arms and ballistics.
We all know that cartridges such as the .45 ACP, .380 ACP, 9x19mm, etc., being "rimless" cartridges, headspace on the case mouth, right? Ergo, it behooves us to ensure that our casings for these cartridges should be of uniform length for optimum performance, right? Perhaps, in a perfect world, but not the reality for most shooters. According to the reloading manuals, the rim of the .45 ACP case mikes 0.4800", the case body 0.4762"above the groove,so it is not entirely accurate to call it a "rimless" cartridge.
Quoting Hatcher on the topic .....
"The true rimless cartridge has a head which is no larger that the body of the cartridge is at some point further forward. It has a groove or cannelure cut around it just forward of the rim, for the extractor to hook into As the rim is no larger than the body, it cannot be used to limit the forward motion of the cartridge when it is seated in the chamber., and this must be accomplished in some other manner. With the.45 ACP cartridge, this is done by leaving the the forward end of the cartridge, that is the mouth, square, instead of crimping it into the bullet as is dome with most other pistol or revolver cartridges. A square shoulder or ledge is left at the front of the end of the chamber and the mouth of the case seats against this square ledge."
In the foregoing, he has described the best of all possible worlds re: the headspacing of "rimless" pistol rounds. However, reading on .....
"It is quite possible to fire the .45 ACP cartridge in the .455 Webley & Scott Self Loading Pistol, even though with his gun and cartridge combination there is about 1/8" excess headspace. If the cartridges are loaded into the chamber singly, they go in so far that neither the firing pin nor the extractor can reach them, and they will not fire; but if they are loaded from the magazine, they can rise up under the extractor hook and this holds them close enough to the breech block so that the firing pin can strike the primer, and they fire, extract, eject and reload just as if they were intended for this gun, in spite of the 1/8" excess headspace. I have fired many rounds of this ,45 ACP ammunition through the .455 Webley & Scott Self Loading Pistol."
"Likewise the 9mm Short, or .380 ACP cartridge, which is .080" shorter than the proper 9mm Parabellum cartridge, may be fired from the magazine in the Luger (P-08) or the P-38 , but this little cartridge has insufficient power to eject and reload, so the slide must be pulled back by hand after each shot. I have fired many of these cartridges in both these guns with no trouble as long as they feed up from the magazine. If loaded in the chamber by hand, they will not fire because the extractor will not catch them at all in the Luger, and only part time in the P-38."
"I have also fired the .455 Webley Revolver Cartridges Mark II in the .45 caliber Colt New Service Revolver with an excess headspace of .037", and I have fired the .455 Automatic Webley & Scott Pistol Cartridge in this same Colt New Service .45 with an excess headspace of .025". Likewise, in trying everything I could think of, I have fired quite a few .45 ACP in a Colt New Service Revolver caliber .455 with an excess headspace for this combination of .051"."
Note the following which should be underlined for effect:
"In all of the above shooting, accuracy was excellent, and no bad results of any kind were observed. The only trouble to be expected was a possibility of hangfires or misfires from having the primer too far away from the firing pin, but even this did not occur."
To sum up Hatcher's thoughts on the matter:
"Headspace, like that when we fire the .380 ACP cartridge in the Luger pistol is really never any greater than the distance the extractor lets the case go away from the face of the bolt. Without the extractor holding it, the case might go quite a way in, but when it is held by the extractor, it cannot go very far, and this limits the headspace, and holds the cartridge close enough so that the firing pin can set off the primer."
Wiley Clapp (ex-USAF Armorer and gun writer) writes about a friend that delights in torturing him with pics of one hole targets fired at 25 yds from a known accurate 1911 using a Ransom machine rest - loaded with range pick up brass!
So much for that "myth".
My .45 ACP brass is never sorted. It is a mix of GI, Norc, Federal, a lot of it range pick ups. It has never been trimmed. OAL is uniform and rounds are taper crimped. My guns function flawlessly with it, but it does make itself known over a chronograph. Loads that make IPSC Major in some cases score low in others, so it behooves me to (a) sort accordingly or (b) load to ensure Major with all cases. That or declare Minor and carry on.