Comparison of various assault rifle cartridges all loaded with pressure-safe loads and all with the Sierra MatchKing bullets to enable a consistent basis for comparison. The SMK was chosen because it is identical to or very close in construction to current US DOD bullets which have been certified as Hauge Legal for combat by the JAG. The 7.62x39 was loaded with a Spitzer bullet as no SMK was available. I do not believe this changed any conclusions regarding its overall performance relative to the other cartridges. The 5.8x42 Chinese round's BC and velocity was calculated based on my own estimates and extrapolations as well as photographs and other information supplied by Stan Crist and several other ballistics experts who I wish to thank at this time. This graphic was in part an attempt to quantify Stan's recent claim in his Infantry Magazine piece...

The 6.8x43mm and 6.5x38mm are the most capable upgrades, but they are also the most expensive. The 6.8mm SPC would provide a substantial improvement in close combat capability, which was its stated design purpose. However, the streamlined projectiles fired by the 6.5mm Grendel deliver vastly superior all-around performance, combining improved terminal effects with greatly enhanced capability to “reach out and touch someone” at long distance.

The bulk of the information contained in this graphic can be easily obtained from pressure-safe reloading tables on Hodgdon's online reloading site and from Sierria Bullet's online tables. The idea behind expressing this information as a percentage of the 6.5 Grendel's retained energy was to make for quick comparisons. Obviously the choice of which cartridge to use as a baseline comparison does not affect the relative performance of the cartridges in any way. These percentages were retained in table form at the bottom of the graph so at any range one can easily compare the retained energy of any of the various cartridges.

There is an extended discussion of the methodology and estimation techniques used in the construction of this graphic on the 65Grendel.com website on the Wiki Page threadbase. This discussion and the ancillary offline emails attendant with it easily exceeded the total size of the Wiki Assault Rifle page so even a summary discussion would be unacceptably large within the context of the Wiki Assault Rifle page.

• Stanley C. Crist, "Small Arms Ammunition for the 21st Century: Hight-Performance Alternatives to the 5.56 NATO Round" (pdf), Infantry magazine, May-June 2006