For years, long-range shooters have been pushing the limits of different short action magnum cartridges. Short actions appeal to hunters and long-range enthusiasts due to their shorter bolt throw, allowing quicker follow-up shots and weight savings for those ounce counters. Although cartridges like 6.5 Saum and 300 WSM were designed for use in short actions, shooters have become frustrated with one specific issue over the years. The cartridge length is limited by the length of the short action magazines if they want the rifle to be a repeater.
To use heavier, higher BC bullets, you have to be able to push them fast enough for them to be beneficial at longer ranges. This means more case capacity is needed. Obtaining more case capacity requires the bullets to be seated out further, making more volume for powder. By doing this, the case's overall length will be too long to fit into a short action magazine. What have shooters been doing to fix this? They have had their dream rifle built off a long action. Long action magazines will give you WAY more internal magazine length than you will ever need, but it will almost guarantee that you will also have feeding issues.
Action manufacturers such as Defiance machine, Lone Peak Arms, Zermatt Arms, and Stiller have all noticed the COAL frustrations and have developed a solution. They are now making medium-length actions. These actions allow shooters to gain .305 inches of coal over a short action magazine. So those high BC bullets we all want can be seated out further and we get the case volume needed for these awesome short hotrods. While the SAUM and WSM cartridges led the way to this change, 6.5 PRC and 6.8 western have also increased the demand for these medium length actions.
In the video below, you can see the length difference in the 6.5 Creedmoor and 6.5 PRC. Both of these are short action calibers, but for the hand loader, a 6.5 PRC that is throated out will allow them to seat 153 grain Hornady A-Tips, or 156 Grain Berger EOL out further and capitalize on the performance. With the Creedmoor, you could shoot the 153 or 156 grain bullets without any coal issues in a short action.
Some critical information to be aware of while deciding which medium length action to purchase is that Defiance will call theirs an XM. The reasoning is that they already have the name medium used for their 700 short action clones. What they call a short is actually a Remington model 7 footprint. Leaving the title for the actual medium length receiver to an "extra-medium" abbreviated to XM.
Lone Peak Arms, Zermatt, and Stiller are all called mediums, and fortunately for them, all share the same footprint. At XLR Industries, we offer both a Lone Peak Medium (covers Zermatt & Stiller) and a Defiance XM inlet in our Element 4.0, both aluminum and Magnesium chassis models.
If you ever have questions about what action, caliber, or chassis might work best for you, feel free to reach out, and we would love to get those questions answered for you!