.40 S&W (using Hornady bullets)
Date: Jul 20 2012
Since its introduction in 1990, which was a team effort between Smith & Wesson and Winchester Ammunition, the .40 S&W has become a huge success as it offers greater power than the 9mm and less recoil than the .45 ACP. It is well established as a selfdefense, law enforcement and sporting cartridge, but in proper guns and with correct ammunition is also unusually accurate.
With many auto-loading pistols available from all over the world, along with domestic and foreign ammunition makers, some problems have surfaced of which handloaders should be aware. For instance, brass cases have been observed that have very thin walls. When these fired cases are full-length sized to their original specifications, case mouths expand and internal dimensions are still too excessive to obtain that important tight bullet and case fit. As a result, bullets literally drop into the case with little or no resistance, and when crimped in place there is very little bullet pull. This results in less than reliable ammunition and can actually be dangerous if bullets become deeply seated while hitting the feed ramp. These out-of-spec cases should be avoided for handloading. For data developed herein, Starline cases were used exclusively. They are dimensionally correct and eliminate the above problem.
Various Glock .40 S&W pistols are very popular; however, in this caliber they feature an unsupported chamber to aid in feeding. This leaves fired cases with what is commonly known as the “Glock bulge”, just forward of the case head, which cannot be removed through normal case sizing. To correctly remove this bulge and bring the case back to correct industry specifications, I recommend the Redding GR-X Push Through die with E-Z Feed push rod. All cases are pushed through this die (using any common press), followed by full-length sizing in carbide cases. This brings them back to correct specifications for reliable chambering.
Maximum average pressure is 35,000 psi. In such a short case, small changes will change pressures substantially. For example, changing primers may change pressure by 10,000 psi or more. It is suggested to always use standard Small Pistol primers only with the accompanying data being developed with Winchester Small Pistol. Another important tip includes seating bullets to exact depth (or overall cartridge length) as listed. If seated deeper, pressures will likely spike to dangerous levels. With such a short powder column charges should also be exact, especially when assembling maximum loads.
Always taper crimp bullets, preferably as a separate step after seating bullets. The case mouth or crimp should measure .423 inch, which can be measured using blade calipers.