The 308 SCA Semi-Caseless Ammunition by Wild Arms Research and Development

Luke C.
by Luke C.
The 308 SCA Semi-Caseless  Ammunition by Wild Arms Research and Development

Since the dawn of firearms, mankind has always sought to reduce the weight of the load on the bearer of the weapon. Caseless ammunition was a major step in this direction beginning in 1848 by Walter Hunt and his “Rocket Ball” ammo. Jonathan at Wild Arms Research & Development (WARD) has taken another crack at advancing the concept of caseless (or semi-caseless in this instance) ammunition with his 308 SCA semi-caseless ammunition.

The 308 SCA Semi-Caseless Ammunition by Wild Arms Research and Development

The 308 SCA Semi-Caseless Ammunition by Wild Arms Research and Development

Before we look at the new semi-caseless design from WARD, I want to take a look at the more widely known caseless ammunition and explore the advantages and drawbacks that it has so we can better understand what WARD is trying to accomplish.

Photo: Matthew Moss (The Armourers Bench)

Perhaps the most popular example of a firearm using caseless ammunition is the HK G11 Rifle. Early iterations of the HK G11 were prone to a problem known as “cook-off” wherein the round is prematurely detonated and may even cause sympathetic detonations as a result of the first. The brass or steel cases of normal firearms almost entirely mitigate this problem as the case itself acts as a heat sink protecting the propellant from the heat of the chamber.

The 308 SCA Semi-Caseless Ammunition by Wild Arms Research and Development

The nitrocellulose blocks used in the G11’s 4.73x33mm ammo ended up cooking off rounds and more research was poured into the design and eventually brought the cook-off temperature to more acceptable levels. However, even with this advancement, the problem of the firearm rapidly heating up still remained as caseless ammunition dumps all of its heat and energy directly into the firearm as opposed to being contained inside a case and eventually ejected from the firearm.

The VEC-91 was only imported into the United States in limited numbers and was not a commercial success overall.

In 1991 Voere created the VEC-91 which uses very similar ammunition to what we are discussing today, however, the VEC-91 never took advantage of the design of the cartridge (5.56mm, 5.7mm, and 6mm) outside of a single bolt action rifle that ended up being a commercial failure. Not to mention the VEC-91 also required two 15-volt dry cell batteries which would last about 5,000 rounds before needing replacement.

The Wild Arms Research & Development Semi-Caseless Round

Proposed Specifications 308 SCA:
  • Case/Projectile Material: Machined or Swaged Brass
  • Projectile Weight: 120 Grains
  • Propellant Capacity: 10 Grains (more capacity with a reduction in projectile wall thickness)
  • Primer: Combustible rear primer
The 308 SCA Semi-Caseless Ammunition by Wild Arms Research and Development

I spoke directly to Jonathan about these new rounds and he generously shared with me many of his design details and future plans. He is pursuing the design and implementation of the cartridge as a passionate side project so don’t expect any mass-produced versions of this ammunition any time soon!

The current projectiles are made from brass like many firearm casings, however, the projectile in this instance also happens to be the case. Just like the old Volcanic rifle cartridge, the semi-caseless round will combine the case, projectile, propellant and primer all into one package.

The 308 SCA Semi-Caseless Ammunition by Wild Arms Research and Development

The 308 SCA in its prototype phase makes use of conventional smokeless rifle powders, a milled or swaged brass case/projectile, and a seated primer held in by an adapter. Later designs will fully incorporate the powder and primer into the case like the H&K G11 caseless ammunition just placed inside of the semi-caseless design.

The 308 SCA is very similar to the early Volcanic round which was an entirely self-contained bullet/projectile.

As a side effect of having a brass projectile, you end up having increased bullet penetration over that of conventional lead ammunition even with less powder being used overall. This design was proven to work in the Benelli CB M2 which used a 9x25mm AUPO round. As a solid proof of concept, Jonathan took elements from the 9mm AUPO round and adapted it for use in an AR-15 sized platform.

Benefits and Design Challenges

The main benefit Jonathan hopes to achieve with this design is to first, eliminate the failings of standard caseless ammunition the most important of which is cook-off. Secondly, he hopes to achieve not only more compact and lightweight ammunition but also include armor-piercing capabilities into the design. Finally, he hopes to achieve all this by only changing out a few key components which would be the bolt, barrel, firing pin, and magazine. Jonathan currently is making plans to use already existing FN Five-seveN magazines that are compatible with suitable AR-15 lowers.

The extended bolt lugs of the 308 ARC bolt

This is already done to an extent with other AR-15 conversions such as conversions from 5.56 to .458 SOCOM or 300 AAC Blackout. However, the semi-caseless design carries with it some inherent challenges. One such challenge is that of creating a proper gas seal. Without a case to contain the initial blast the bolt must make a proper seal without the aid of a primed case.

Part of the two-piece firing pin

To solve this part of the problem Jonathan designed a two-piece firing pin that effectively seals off the chamber and prevents gas from escaping through the firing pin hole. In tandem with the designed extended bolt lugs and bolt face, this should delay the rearward travel of the bolt similar to a delayed-blowback submachine gun.

The 308 SCA Semi-Caseless Ammunition by Wild Arms Research and Development

One of the final hurdles he has to go through is designing and integrating a reliable extraction and ejection system into the bolt for clearing any potential malfunctions and safely unloading the firearm.

The 308 SCA Semi-Caseless Ammunition by Wild Arms Research and Development

Future Plans for the 308 SCA

Jonathan told me that he plans to do live-fire testing of the 308 SCA sometime soon using a newly assembled single-shot AR-15. Once testing takes place he feels that he will have more conclusive data on the design to take the next steps which include using a nitrocellulose-type powder/primer compound to make the projectile fully self-contained.

Jonathan's future plans with the semi-caseless design concept.

If Jonathan is successful with his 308 SCA concept, he also has plans for a much larger and more versatile projectile that will work in a 408 sized platform, the 458 Automatic Anti Materiel Rifle. If you’d like to check out Jonathan and Wild Arms Research and Development you can get the latest updates over on Facebook, Instagram, and YouTube. I’d like to extend a personal thanks to Jonathan for providing all of his photos and research with me for this article, it’s always great to see people passionate about firearms and ammunition development! Don’t forget to check out his cool series of videos on his home-brewed Panzerfaust!

Prototype projectiles
Luke C.
Luke C.

Reloader SCSA Competitor Certified Pilot Currently able to pass himself off as the second cousin twice removed of Joe Flanigan. Instagram:

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3 of 49 comments
  • Guest Guest on Aug 08, 2020

    Caseless ammunition is a dead end.

    The article mentions that the brass case acts as a heat sink protecting the propellant from the heat of the chamber. This isn't quite correct. The brass case acts as a heat sink carrying heat out of the chamber with each ejected casing. Without it, serious, severe overheating is an insoluble problem, especially if full auto fire is a desired function.

    This is also why plastic cased ammunition is a dead end--its heat capacity is insufficient, even when combined with unusual geometries like the old Hughes Lockless concept from the 1970s.

    We have reached the point in small arms where no significant improvement is possible. We reached this point, actually, during the Second World War with the introduction of selective fire platforms using intermediate caliber rifle cartridges and detachable box magazines, before most people reading this were born.

    Everything else is trade-offs now. More powerful cartridges have greater recoil, less full auto controllability, and weigh more, permitting the infantryman to carry fewer. Lightweight aircraft aluminum receivers? Sure--just don't complain if the ultralight rifle climbs more in full auto. Optical sights? There were experimental Garands with integral non-magnifying optical sights in 1942, contemplated for general issue. They were found to be too expensive and too fragile for the minor benefits they provided--and not much has changed except the willingness of Pentagon Mandarins to pay more for an optical sight of dubious ruggedness and reliability (hello, EOtech) than the rifle it's attached to.

    We don't need more high tech small arms. There is no requirement for an infantry rifle that is not met decisively by an AKM from 1960, or an M16A1 from 1973. We already have more than enough cartridges and propellants to choose from. Infantry small unit tactics haven't changed much since 1942, either. Over 90% of battlefield casualties are produced by indirect fire and air power, just like in 1915.

    Western armies don't need new gadgets. Western armies need more time on the firing range and higher qual standards, and less time wasted on "sexual harassment identification training" and a million more PC time-sinks. But no one wants to hear that.

    • @guest There are no "insoluble" engineering problems, there's just technology that hasn't yet caught up. Technology advances, and it will move past this problem as well. I agree with you, though, about the payoff; unless the problems are spectacularly solved, the tradeoffs seem unwieldy.

  • Marcus D. Marcus D. on Aug 09, 2020

    It would seem, as someone suggested below, that a small "case" with a primer, such as a shotgun shell without the shell, would make the design simpler. The propellant is protected/sealed against moisture, and the "case" weighs next to nothing. Either that, or keep trying with the plastic cases. I assume that the fact that the propllant in in the base of the bullet and burns as the bullet goes down the barrel might mitigate heat issues.Where is PCP in all this these days?