Caliber Configuration Podcast with Yours Truly at Gun Guy Radio

Back in March, I wrote a post on caliber configuration, or the effort to create and standardize effective and economical ammunition for infantry small arms. As mentioned in the post itself, it was written as a more in-depth companion article for a podcast recorded by Ryan Michad for a Gun Guy Radio segment at the Firearms Radio Network, which hadn’t been released at the time. Well, the show has now gone live for your hearing pleasure, so you can listen to me ramble on about military ammunition to your heart’s content!

In the podcast, Ryan and I discuss briefly the history of 7.62mm and 5.56mm NATO, history of 5.45x39mm Soviet, and 5.8x42mm Chinese, the state of military ammunition configuration worldwide, and some new concepts and technologies that may be applied to the next generation of military ammunition. Finally, we also dive into the Lightweight Small Arms Technologies project and other lightweight cased ammunition concepts, as well as smaller PDW rounds!

For other radio shows I have done with Ryan, you can follow the links here to other gun discussions about the MP.44 Sturmgewehr, machine pistols, early American selfloading rifles, the story of Colt, and a roundtable discussion on dream rifles with TJ and Weerd Beard.

Go forth and check it out!

Nathaniel F

Nathaniel is a history enthusiast and firearms hobbyist whose primary interest lies in military small arms technological developments beginning with the smokeless powder era. In addition to contributing to The Firearm Blog, he runs 196,800 Revolutions Per Minute, a blog devoted to modern small arms design and theory. He is also the author of the original web serial Heartblood, which is being updated and edited regularly. He can be reached via email at


  • 6.5x55Swedish

    Very nice discussion. Only think I didn’t like was the statement on early calibre thoughts where you basically said that they were wrong in thinking that bigger is better. For a long time it was true. Without jackets for the projectiles and smokeless powder the only way to get more damage was to go big as you were limited in how fast you could go.

    • ostiariusalpha

      Well, he was rather more considering how that black powder boolit era thinking dragged itself into the first half of the 20th century, when smokeless propellants and spitzer projectiles had made it unnecessary. There had been a continuous push toward smaller calibers (30 cal was considered a small caliber in the late 19th century), but the poor terminal performance of round nosed, jacketed bullets had been a serious set-back for the small caliber philosophy.

    • That wasn’t really what I intended to say, but it was an extremely abbreviated discussion. I covered like 100 years of history in a minute or two. Bound to be a little garbling.

      • 6.5x55Swedish

        Yupp, only finding one thing that comes out wrong in an hour long show isn’t bad. 🙂

  • mechamaster

    Good food of thought podcast.
    Still learning and enjoy the study of the future caliber potential.
    I like the idea to replace or subtitute the .308 / 7,62x51mm with 6-7mm General purpose cartridge. and improved 5,56mm into more aerodynamics and efficient. like Soviet did with 5,45

    • Cmex

      What are you smoking and how can I get some? We should keep our 308 or replace it with something like either 25-06 or 338 Lapua. The reason why I say this is because it would further increase our range with a negligible increase in weight. Now, 5.56 ought to be replaced with some kind of 6.5mm round — light, low recoil, hit hard. We’ve hit the limit as far as 5.56 goes and we’re trying to solve the lack of lethality issues in a fragmentation-dependant round by making it even better at penetration. Try to puzzle that out for yourself. Study after study has found a 6.Xmm round to be the ideal infantry caliber, although Nat claims to have access one one that says it’s close to 5mm, although he’s so far declined to share it with anyone and all the powers of the internet and doing searches in 3 languages across 5 search engines and asking across multiple forums have turned up nothing. IMO, with rounds available right now, I’d replace 7.62×51 with 270Winchester for a full 33% increase in energy for negligible increase in recoil and an improvement in ballistic coefficient. I’d replace 5.56×45 with 6mm PPC, a very accurate cartridge with a very high increase in energy and ballistic coefficient from 5.56 at negligible incresae in weight and recoil.

      • .25-06? How many spare barrels to you want to force the Weapons Squad to carry, man?

        I feel like Sisyphus whenever anyone brings up the “all studies ever done have all concluded the 6.5mm is best”. It’s my fate to just keep pushing that boulder uphill, says the Oracle at Delphi.

        Well, here’s a head-scratcher for you: For almost half a century, most studies concluded in countries across the world, with a handful of exceptions, determined that .30 cal was the best infantry caliber there was. France, Japan, the USA, the Italians, and numerous others all conducted studies and came up with .30 cal as the “ideal”. So why didn’t they all conclude that 6.5mm was the best? Were they all stupid?

        No, they had different requirements. There are requirements that will lead any research team to conclude that 6.5-7mm is the best caliber, but not every study started with those requirements (in fact, most didn’t).

        It continues to baffle me that this myth gets repeated in serious ammunition discussion circles so often, as many times I’ve seen it rolled out again by people who are aware that in the 1950s, the US Army conducted a caliber configuration study and settled on the .22 caliber! It was that study led directly to the 5.56mm. Here is my proof that this study occurred, below are cartridges in my collection, some of which were created for that study:

        The middle three are the .22, .25, and .27 Light Rifle, each basically 7.62 NATO necked down to its respective caliber.

      • iksnilol

        Cause an improved high pressure 6.5mm round like the 6.5 Unified (from Soviet Union) would be lighter than 308 whilst providing better range and trajectory.

        • The cartridge you’re thinking of is the 6mm Unified, not 6.5mm.

          • iksnilol

            That is correct.