Since I was testing jacketed bullet designs in the .45 Colt at the time, it didn’t take long to find the limited bullet pull produced by the .450 inch inside neck diameter led to nothing but problems when working with moderate- to slower-burning powders like 2400, IMR- or H-4227 or H-110.

The short-term solution was to use a coarse grinding wheel to cut the lower .25 inch off the full-length sizing die to allow the case to enter the die far enough to provide a more appropriate neck length, producing a firm grip on the bullet, from the crimp groove to the base. To remedy the sloppy bullet pull, I turned the expander plug down to .448 inch. The net result was velocity from a 4 3/4-inch Colt barrel increased from 100 to 120 fps, depending on the powder charge, and unburned powder residue was reduced considerably.

The long-term solution was to put in a call to Bill Keyes at RCBS (who has since retired) and explain what I had done to their .45 Colt dies, and why. Bill asked that I forward a few fired cases, and he would see what he could do about building a proper set of dies.

Shortly thereafter, RCBS delivered a new set of .45 Colt dies that did everything a serious handloader could ask for. First, they reduced the case body of a fired case by a mere .003 inch, whereupon they tapered gradually to produce a .4 inch case neck and a .448 inch inside neck diameter. The neck expander also measured .448 inch and served only to round out the case neck and bell the mouth to accommodate trouble-free seating with cast and jacketed bullets. The dies are stamped Aug 1981, and RCBS .45 Colt dies have been similar since that time. Interestingly, some outfits that publish reloading manuals were still using the older die configuration until just the last few years, no doubt wondering why their ballistic results were falling well below what reloaders were obtaining with the same components assembled in modern dies.

The reason those new RCBS .45 Colt dies worked as well as they did - and still do - was they produced a loaded round that fit the chambers the cases were fired in as closely as possible and still provided a firm grip on a properly sized bullet.

I got along fine with those RCBS dies for many years - until every outfit started putting out carbide full-length sizing dies. But alas, the carbide dies just created - or re-created - another set of problems the steel dies were designed to eliminate: excessive working of the case that produced a very sloppy fit in .45 Colt chambers.

The problem with carbide dies is that the .45 Colt case is not straight; it tapers slightly - from .480 inch just in front of the extractor groove to .474 at the mouth, depending, of course, on whether the seated bullet measures .451, .452, .454 or .456 inch. To work properly with modern bullets sized to .451 or .452 inch, the carbide die is designed to produce an inside neck diameter of .448 to .449 inch, which means the entire case length is reduced accordingly, for an average outside body diameter of .469 inch, .013 inch less than SAAMI recommendations for factory loads.

What matters here is that the typical carbide sizing die generally reduces the case body diameter more than necessary, and in the process, produces a fairly sloppy fit in the revolver chamber. It seems rather silly to worry over precise bullet diameters and minute changes in powder charges when the case doesn’t even fit the chamber, leaving the loaded round lying in the bottom of the chamber and the bullet ricocheting off the tapered area between the case mouth and the chamber throat. More often than not, the bullet enters the forcing cone at an angle, which is traced from the fact the bullets often have irregular engraving from the lands and grooves, usually more contact on one side of the bullet than the other, which in turn, in the worse case scenario, results in a bullet that is not round, but oval.

The solution goes back to one of two choices: have a custom steel sizing die made up that produces a loaded round that fits the chamber the case was previously fired in or neck size the case necks only with a carbide die, leaving the remainder of the case body to form a reasonably good fit in the chamber.

For those of us who enjoy the carbide die for the labor-saving characteristic of not requiring lubrication, neck sizing is the best solution. With this technique, however, after one or two full-house reloads, the case body must be sized so the loaded round will chamber a third or fourth time without undue force. With midrange loads neck sizing works fine for three or four reloads before full-length sizing is required again.

Not only does neck sizing work for several revolver cartridges, but you can use the .45 Colt carbide die to neck size .45-70 brass, (using the .45-70 neck expanding die to bump the neck back to proper inside diameter) so long as the resultant loaded round will chamber easily again. I use the .45 Colt carbide die to neck size .450 Alaskan cases, resorting to full-length sizing only when necessary. For all this experimenting and fiddling around, I have never had a neck-sized .45 Colt, .45-70, .44 Magnum or .450 Alaskan round fail to chamber in the field - mostly because I run them all through the firearm in question prior to taking those rounds afield.

The only problem that might result in neck sizing revolver cases is that some revolver chambers are larger, or smaller, than others - especially .45 Colt sixguns from Uberti, Armi San Marco, Colt, etc. You simply have to make sure the loaded rounds wind up being used in the same handgun. If the chambers in one sixgun measure .482 inch, for example, and those in another run .483 inch, then the cases fired in the latter won’t fit in the former unless they are full-length sized in a steel or carbide die.

The question is whether or not improved case sizing techniques will result in improved accuracy in any given handgun. Going back to tests that began after RCBS shipped the steel dies in 1981, I saw improved accuracy and reduced velocity variations almost from the start. Since the sixgun in question was a run-of-the-mill first generation Colt Single Action Army .45 Colt with all the inherent problems we have come to accept as common to the cartridge and sixguns that are chambered for it, it is fair to say that old Colt was fairly typical of the breed. With properly sized bullets that are cast of proper alloy, or most jacketed bullets, this sixgun will keep five shots inside 1.5 inches at 25 yards with a variety of loads using neck-sized cases or brass sized in the full-length steel sizing die that Bill Keyes made up.

Switching over to a Ruger Old Model .45 Colt with a 4 5/8-inch barrel with .452-inch chamber throats, most five-shot groups are less than 1.5 inches. The last batch of loads using neck-sized brass with 18.0 grains of Hodgdon Lil’Gun with Nosler 250-grain jacketed hollowpoints hovered closer to one inch at 30 yards. If nothing else, loads using .45 Colt neck-sized brass are more consistent in terms of accuracy and velocity. The same goes for selected loads put up in Winchester .44 Magnum brass that are neck sized and fired in a Smith & Wesson Model 29 or a Ruger Old Model Super Blackhawk. The common denominator is if a load is any good at all, it should, and usually does, shoot a bit better when the case fits the chambers as a result of neck sizing.

There is at least one other option - use a Keith-type semiwadcutter cast bullet design with a front driving band that helps align the bullet in the chamber throat. The idea is to have a front driving band that is wide enough to actually enter the throat when the loaded round is chambered. That was the idea behind Elmer’s original Lyman 429421 .44-caliber design and his Lyman 454424 bullet for the .45 Colt. My RCBS 45-270-SAA, while heavier than the Keith bullet, has a front driving band that measures .010 inch in width, which in turn helps align the bullet in the chamber regardless of the sloppy chamber dimensions. The RCBS 44-250-KT is also true to Keith’s original 429421 semiwadcutter design and should help improve overall accuracy where .44 Magnum chambers are a bit loose.