British Ammo Improvements

It isn’t just the USA that’s turned away from the 1970s-vintage SS109 round (which is what our 62-grain M855 was, essentially) in pursuit of more accurate ammunition with improved terminal ballistics. The UK has done so, also, although they’ve gone in a different direction from the US.


BAE Radway Green, the Britsh military ammo monopoly contractor, has also improved the venerable 7.62mm round. The British tech ‘zine The Register visited Radway Green and has a rundown on the new ammo — heavy on The Reg’s patented juvie snark, but well-stuffed with technical details.

What’s changed? … It’s all down to penetration – or punching the same depth of hole in ever-better-protected targets.

While RG’s existing products, the 7.62mm L44A1 and the 5.56mm L17A2 cartridges, did that more than well enough when they were originally specified by the Ministry of Defence, modern battlefield technology and techniques mean the military are looking for something with a bit more oompf to fire down their rifles and machine guns.

RG has swapped all-lead bullets for steel in pursuit of better penetration against hard targets – though there’s a lot more to it below the surface.

The two new designs of cartridge, known as the Enhanced Performance (EP) round in 5.56mm and the High Performance (HP) round in 7.62mm, feature new – and, in the HP’s case, heavier – bullets. In addition, the HP round switches from single-base propellant powder to double-base, to give the heavier bullet the same flight characteristics as the old one. The EP also discards the age-old NATO SS109 bullet design, which incorporates a steel tip in front of a lead core, for an all-steel bullet, cased in the same gilding metal jacket as before. Its profile is similar, though.

The genesis for this seems to be the same as that for the US Army and USMC’s newer rounds — technology made better ammo possible. Unlike the Americans, though, the British Army didn’t have to sell the ammo as a “green” boondoggle to social-engineering obsessed Ministry of Defence.

Simon Parker, a project manager at BAE Systems Radway Green, spoke to The Register about the new rounds and the decisions behind the changes in their makeup.

“We wanted to see if we could improve performance against hardened targets. Having a solid hardened steel core improves performance above that of the steel tipped round,” he said. The new 5.56mm round, which will be known as the L31A1 in British service, retains a bullet weight of 62 grains (4g), meaning its ballistic performance will be very similar – an important similarity for soldiers firing it down their SA80 rifles.


For the 7.62mm round, known as the L59A1 in British service, the biggest change is to the weight of the bullet, from 144 grains (9.3g) to 155gr (10g). This increased maximum weight allows the new bullet to incorporate a steel tip, similar to the 5.56mm NATO SS109 design, giving it more mass with which to punch through a light target. Graphs from BAE claim that the HP bullet can penetrate an 8mm steel sheet out to about 400m, whereas its predecessor could only manage it at half that distance.

“We have a standard ball round which is 144gr and a sniper round which is 155gr. The sniper round is manufactured under tighter tolerances and conditions. The 7.62mm High Performance round is not quite the same as the sniper [round] but it’s considerably improved over the standard 144gr bullet,” said Parker.

The propellant in the new 7.62mm round is the same as the 155gr L42A3 sniper rifle round, which is continuing in production. It is a double base propellant – so why the change from single base?

“It’s merely because it’s heavier,” said Parker. “Moving from the 144gr to the 155gr means you need a bit more energy in the propellant. We already use the double base propellant in the sniper round so it’s the same propellant as is used in the sniper round.”

It’s interesting to note that the 5.56 round is Boxer primed, and the 7.62 Berdan primed.

Yeah, but how does it work in the real world? Does it pop hadjis?

“The old Green Spot was just the best lot of ammunition that we manufactured, taken off and marked as Green Spot… but 7.62mm HP would outperform Green Spot,” said Parker.

“We’ve not designed it for a sniper rifle application – though the Special Forces use it as such and that’s fine – but it has been adopted in the sharpshooter rifle [the Army’s L129A1]. It was purchased as a UOR and subsequently adopted. We recommended the use of 7.62mm HP and the user really loves it. But it was originally designed, truth be told, for improved target performance through any weapon system. We made it and designed it so it can be functioned through the GPMG and it’s also being used by the Royal Navy in their Miniguns for defence of ships.”

Do Read The Whole Thing™. The section on the environmental testing that the ammunition endured on its way to acceptance — and that samples must continue to endure — is quite illuminating all on its own.

For more information, BAE Systems has a page on the new ammo, with a rather cool video we were unable to figure out how to embed — so go there to watch it. The ammo has been in production for the UK MOD since 2015, but is now being offered to other military forces.

34 thoughts on “British Ammo Improvements

  1. Tierlieb

    Calling it HP for “high performance” is probably not the best decision. Because everyone knows “HP is forbidden” (after 2 secs of googling) or “HP is forbidden for the military” (4 secs of googling).

    On a different note: I wonder if insisting on a 1/10″ twist for my AR-10 (or, technically, “AR-15 in .308” or “SR-25 based rifle”) was a good idea. Seems all the important western militaries like their 1/12″ twists and their lighter ammo. That results in comparatively lightweight surplus ammo.

    Does anyone know why? Tracers and hardened-steel-penetrators tend to be lighter than full lead bullets, so is this a compromise to get a similar bullet weight for all types? Or do 155gr bullets stay supersonic longer than 180gr, even if the latter have better aerodynamics?


      No the 155 does not have any advantage over 175 at longer ranges. the old 155 palma load was a tradition and had some mid range performance that was good enough, . And no doubt back in the day the slightly less weight made a difference in cost and weight but it also cut back on recoil. The M1 and M2 ball ammo for the 30.06 illustrates this pretty well. The heavier 30 cal load did everything better. But then when jJoe Schmoe didnt like the recoil on the KD range and when the gov took a look at the cost of extending the shooting ranges to better suite the heaver LR round among other reasons, the lighter ball round was reissued for training. Then every one just sort of forgot the whole point of the heavier round and its abilities. But modern heavier HPBT and VLD match bullets eclipse 155s or any light weight round. You made a wise decision to opt for the 1/10 barrel. This way you get the entire range of weights and you have the best benefit, which is more choices on the heavier end. I would not/and do not, even bother with 308 weights under 175 for anything more than plinking at pop cans. People keep thinking a fast twit means you can not shoot the lighter surplus stuff or match ammo as accurately and thats just Pure D bullshit.

      1. Tierlieb

        Thanks for your insights, Looserounds.

        Personally, I wasn’t too worried about a faster twist having problems with lighter bullets (especially since 1/12″ and 1/10″ is not a big difference compared to what 5.56×45 deals with), but about missing a trend. The latter is a horrible thought ;-)

        Jesting aside: In my rather limited experience, a modern bullet is usually better than an older one. If lighter bullets get more attention because they are what the military continues to use, I would expect to find lighter bullets that outperform heavier ones when using a mixed set of parameters (engagement distance, precision, penetration, terminal effect) in the future.

        And I still wonder if having a tracer and a penetrator with similar ballistics is a criterion for military selection and if the 180gr-equivalents would have an OAL that is too long for SR-25 or 7.62×51 NATO STANAG mags.

        But for current bullet choices, I am very happy to hear you prefer the heaver ones and a faster twist.


    Great stuff Hognose! Thank you once again for the effort you put into this terrific website.

    1. S

      RHA = Rolled Homogenous Armour. These days it refers usually to RHAe, e = equivalent, as a metric to compare effectiveness of modern composite armour.

      So, NATO is adopting Stahlkern (SmK), 70 years later. Is Hadji taking to wearing plates under the man-dress, or is NATO gearing up for little green men?

      Here’s an interesting article about exterior ballistics from Hornady as a primer for Tierlieb; the denizens of Hognose’s comments community are about to answer in detail. After reading that, it confirms my desire to delve into black powder cartridge shooting: one can get away with cast lead and approach the same bullet precision and do it on a shoestring backwoods budget when the shops are closed for whatever reason. Shoot’n’scoot.

  3. Steve

    I wonder what the terminal effectiveness of the new 5.56 is against soft targets. SS109/M855 isn’t great, and I know M855A1 is supposed to improve on it quite a bit. I can’t imagine the homogeneous steel core of the new British load will help with tumbling, expansion, or fragmentation.

  4. James F

    Apparently not–the spam protection ate it. But I think it can be embedded using the iframe from source code in the BAE site, but it’s probably more trouble than it’s worth.

  5. Brad

    pet peeve

    Why is it so fashionable these days to call ammunition with a hardened steel core penetrator “ball” ammunition instead of “armor piercing”?

    1. Hognose Post author

      Because it’s a mild steel penetrator, not AP. AP has a hardened steel, or more usually these days, tungsten carbide penetrator.

      1. Brad

        Mild steel penetrator? Uh, there are multiple references in the text and graphic to the “hardened steel core” of the new British “enhanced performance ball” 5.56mm ammunition.

        1. Kirk

          What the term “hardened steel” may mean to the technical dolt journalist writing these articles is one thing; what it actually means to an engineer or ballistician is another. You could argue, with some facility, that all steel is “hardened”, in that it’s been worked and heat-treated on the way from the crucible to being inserted into the projectile; however, the question of “is it actually hardened to armor-penetration standards” is quite another.

          The language is slippery, and the transmission means, via technically doltish journalist, from technical expert (who may have also been trying to explain things in laymen’s terms) to reader is fraught with potential for misunderstandings.

          I think we’d need to see the actual production specifications and so forth, as well as decide on a definition of what the hell “hardened steel” actually is, in this context, before we were to settle this question. It may indeed be mild steel, somewhat hardened by processing, vice something actually made to be a case-hardened armor penetrator. So, both descriptions could be right, or they could be wrong. Depends on the viewpoint, I suppose.

  6. Aesop

    Thanks for the update.

    Inevitably, to get deeper penetration and longer range, they’ve traded something else; likely expansion and terminal effectiveness when it hits outside the CNS/heart target zone, just as we found out in practice with the SS109/M855 round, and which evidently doesn’t look like something they were testing for to begin with here.

    Range is nice, and hits count, but DRT brings an undeniable lure of terminal extinction of one’s immediate enemy to the table.
    Especially for any enemy for whom care for their wounded relies heavily on inshallah, and booby-trapping wounded to kill a few more infidels is considered sporting play.

    There are no death rays, just choices and outcomes.

    1. Kirk

      And, it has long been my contention that we really don’t know what the f**k we’re doing with all this.

      There’s an intersection out there, where ballistics, projectile design, and tactics all meet up. That intersection is one we don’t know very much about, at all, and are studiously ignoring.

      I frankly think the entire question of “conformity to international law” when it comes to projectile design is specious; the whole restriction on so-called “dum-dum” bullets is based in Imperial German pre-WWI propaganda against the “evil British Empire” that was supposedly using such rounds against innocent Afrikaners. It was a non-existent “thing” back then, and it still is. I’ve yet to be convinced by any of the arguments made by the fools and poltroons of the world that it’s somehow a more moral thing to shoot someone a dozen times with a non-tumbling, non-expanding round than to shoot them once with an expanding tip round that rips great big holes in their bodies. No matter how you do it, the trick is to stop them–And, if you’re going to have to stop them anyway, you’re going to keep shooting them until they do stop. So, the benefits of morality are that we shoot someone a dozen times, to make up for the one round of expanding ammo that would have stopped them with one shot, immediately…?

      The whole idea is questionable. Add in the factor that all this was decided back in the days before modern medicine, as we covered in the post earlier about mouse guns, and the utter lack of logic and humanity designed into these projectile proscriptions from the beginning start to look really, really bad. Seriously–Back in the pre-WWI era, you think it’s somehow more humane to wound someone so that they spend weeks in a hospital bed, dying of infection or gangrene, vs. being dead on the spot after having a hunk of flesh torn out of their body big enough that even first aid wouldn’t have helped? Honestly, I really start to wonder if the asses who came up with this crap weren’t some sort of sadists that got off on human suffering.

      All of these current re-designed rounds are really questionable, when you get down to it: The US went for “green”, whatever the hell that is when you’re talking about firearms, and the UK seems to have copied the thrust of it. And, just like the Norwegians found out, the whole thing starts to get really strange once it all intersects–Remember their “green” rounds, that started creating symptoms of poisoning when used indoors?

      I’d like to throw all this crap out, and start from fresh premises, to do what actually works, objectively and with reproducible work. Nobody has yet, to this day, managed to explain to my satisfaction just how it was that the early AR-15 examples in Vietnam produced such incredible results, and yet failed to produce those same results on general issue of the weapon. One would almost suspect that the marketing people had gotten at the works, or something…

      Which, when you go back and look, they had. The amount of wishful thinking, obfuscation, and outright chicanery that has gone on in the small arms world is absolutely incredible, and it should be intolerable. Only it’s business as usual, all around the world.


      I was thinking the same thing.

      It’s so strange to me how after all the complaints of M855s terminal performance, the result is for more hardened AP ammo for deeper penetration on hardened targets and steel. Yet nothing about the need for better terminal performance on human bodies.

      Are they planning to go to war on trucks?

      They seem to really have bought into this new line of thought all the way. I wonder if after a few years of this stuff and M855A1 we will see another period of stuff like the SOST and the Brown Tip SOCOM round.

      1. Hognose Post author

        The M855A1 has got superior terminal ballistics to the M855. On a par with the 77-grain Black Hills which used to be the preferred antihadjitic.

      2. Kirk

        I think the root problem, world-wide, is a complete lack of any interest in actually articulating what the hell it is we are doing out at that intersection I mentioned. The lack of intellectual rigor and failure to construct even a theoretical structure about what we’re doing or trying to do “out there’ is notable. Examples abound, like the XM-25 program, which seems to be progressing just because it seems cool, not because they really have a decent set of underpinnings for it in tactical intent and operational usage.

        The thing that just blows me away is how much money is wasted, and for what little benefit. The Army could have had the benefit of the recently issued “M4 magazine” if they’d just ignored the “not invented here” thing, and adopted the M3 version of the PMag. But, noooooo… We’re going to spend millions trying to recapitulate that thing in aluminum, because… Hurt feels, back in the early days? I still haven’t even figured out what the hell MagPul ever did to the people at PEO Soldier, but it must have been epically hurtful, because instead of taking up from commercial trade something that was highly effective and affordable, they’ve been stonewalled at every attempt to get “official issue” for their products. It’s highly congruous with the whole “Lewis Gun” fiasco, where the Brits wound up getting the benefit of American innovation, while our own troops got issued crap–All due to ego issues in the small-arms procurement arena.

        And, by the little things like the PMag, you shall know the whole. Ever wonder why the M16 TDP hasn’t been updated to adopt little technical improvements like cold hammer-forged barrels the Canadians have had on the C7/8 family since the beginning? Why we don’t have modern coatings on our weapons, as opposed to the antediluvian parkerizing and anodizing that was state of the art in 1960? Ask the asses running our small arms programs, because I sure as hell don’t know. I do know that FN has the capability to build modern hammer-forged barrels, but does not include those on military-spec rifles sold the Army and Marines, because the TDP doesn’t contain the specs for that, and they’ve not been updated. Ever.

        On the other end of the problem spectrum, there’s the little issue of us not having a really solid idea of what the hell it is we want to do with these weapons. Is the individual soldier’s weapon strictly for self-defense within 300m, against infantry? Is it an offensive weapon, geared towards taking on enemy who ambush from afar, with crew-served weapons? Both, sometimes? All the time? What system is supposed to be our primary killer, down at the infantry squad level? Is it indirect fires, spotted by our FSO, while the infantry provide security and protection for him, and occupy the terrain? Do we intend for them to engage the enemy as the primary “weapon”, as an alternative?

        There’s a clear lack of thought going into a lot of this stuff, and that’s reflected in the chaotic mess that is our small arms “program”. We’re trying to shoehorn an individual weapon that was initially purchased to overcome our conceptual failures with the 7.62 NATO and M14, as they were shown to be inadequate going up against Soviet hardware and tactics in a jungle environment. After that, we force-fit the M16 and 5.56mm into a mechanized warfare paradigm for the Central European battlefield of our imagination, and (thankfully…) never really validated it. Subsequently, we took those systems into an ROE-restricted environment that put far more emphasis on small arms than we’d heretofore encountered, and hey! Presto!, here we are.

        The commentary has been that the British nation acquired its empire in an absence of thought. Something similar could be said about our small arms programs, because I’ve seen f**k-all for anything even approaching a good, solid theoretical basis for even sort of explaining what the hell we’re trying to do in this arena, or how it all fits in with our chosen tactics and operational intent. Again, the XM-25 program just exemplifies the whole problem–I could see the 25mm grenade as being effective, fired from a fixed base like a tripod, and fully automatically, in order to get enough of that minuscule payload into the enemy’s vicinity. But, fired semi-automatically, offhand, and off some poor grunt’s shoulder? Who the hell are we kidding? Carlos Hathcock couldn’t fling that thing’s warhead into a window opening or firing slit at 800m, where we really need to be able to do that, in order to be even halfway effective.

        1. Tierlieb

          There are a lot of issues at work, I think. Looserounds and Kirk have mentioned quite a few of them:

          There are politicial ones – I guess the ban on expanding rounds was supposed to be a typical political statement and quite toothless: Otherwise it would have been applied to more than small arms – as every astute reader points out after learning about the treaty. But a hundred years of unintended consequences show it hurts military capabilities a lot.

          There are engineering issues – tell an engineer you are not allowed to build for optimum expansion and that advertising the, uhm, “deadliness” and they’ll optimize for something else – penetration in this case. Which is easily measured. They might have built for deadliness, but the usual selection issue appears: You have bullet that penetrates well and is deadly and one that penetrates excellently but only pokes small holes. Even if everyone knows what is needed, you have to select the better penetrator because that is your only allowed criterion. Public accountability and all.

          There are advertising and analytical ones: Whether a round works well depends on so many factors (distance, angle, armor, shot placement, psychology) that there is not much difference between using skewed data (data from one type of engagement is always skewed, data from combat engagement cannot be taken while it is happening, which leads to guessing afterwards) and making it up completely.
          Attempting an example: If someone had seriously looked at just Vietnam jungle fighting, we might have ended up with a large bore SMG, not a small bore rifle.

          There are military ones: The perfect rifle with the perfect round works only perfectly for one given environment. Optimizing the gun for the last engagement leads to things like the “skinny” issue in Somalia or the “outreach” problem in Afghanistan. And we all know that imagination has always been the bane of military planning.

          And within all that we have a lot of secrecy. When ecological issues are used to push a round that has better terminal ballistics, everyone not in the know must assume someone did something stupid. When SOF simply ignore Hague and use fragmenting copper bullets but deny it, the success gets ascribed to whatever ammo they are officially using.

          Personally, I my feeling is like Kirks and I’d like to start over again. With full transparency. Which we can’t and won’t. So I will have to stick to what Gary Roberts writes.

          1. Tierlieb

            @W. Fleetwood
            Gary K. Roberts, DDS. Does a lot of ballistics testing; if you are looking for an effective .223 Rem load, you’ll find his articles. He seems to avoid having a website, but he’s active on several forums (DocKGR) and you’ll find his articles all over the place, from .gov to prepper boards.

            Fans point of that he has worked for about every three-or-four-letter-acronym organisation there is; detractors call him “just a dentist”, which has kinda sorta become a running gag, Doc Holliday having been a dentist and all that.

          2. W. Fleetwood

            Tierlieb and Mobius. Okay, target seen. Many thanks for your help.

            Wafa Wafa, Wasara Wasara.

  7. Darius Gurius

    Was the British 5.56 HP ball developed with defeating body armour worn by modernly equipped military combatants it’s main role?

    Will the British police be issued the round for potentially armoured terrorists?

  8. emdfl

    Saw an interesting video linked from some site about some supposed new US projectiles – EBR I think was the acronym. Apparently they are mfg’ed using a copper slug as a base with a steel penetrator set on top and then the whole thing locked in a jacket except for the tip of the penetrator.
    Anyhow the penetration video was literally unbelievable. Both .223 and .308 projectiles appear to go about an inch into the jell and then break into the lower part and upper part with some fragmenting. And while that is happening there is a literal fireball coming out of the initial penetration hole. All very impressive and strange.

  9. Al T.

    Few years back, read a Brit sniper’s account of his time in Basra. IIRC, American Green Tip was considered much better at wacking bad guys as the jacket on the UK’s 5.56 was quite a bit thicker and the bullet would not (reportedly) disrupt at all. I do recall at the Joint Services Small Arms Conference (“91 or “92 in Atlanta) that the Red Cross representative presented a paper claiming that 5.56 was unlawful due to it’s possibility of causing nasty wounds. No, really. And we had some two star American General (Barry McCaffrey) who had a rather excellent presentation that noted our small arms were eons behind what modern technology should give us.

    1. Al T.

      Forgot to add – wonder if that Red Cross opinion had any effect in the MoD’s decision to field what essentially amounts to light AP for their small arms?

  10. Kirk

    A thought has reared it’s ugly head, and since its proximate genesis was this particular post, I thought I would spread the wealth.

    I can enumerate a million and one things I find critically lacking or deficient in much of our small arms procurement structure and process. I could articulate reasoned objections to much of what we’ve done, are doing, and will likely do in the immediate and medium-term future.

    What I can’t do is say “Hey, here is what right would look like…”. Perhaps, with the help of the various experts we have who come here to Hognose’s binary manor, we might discuss what “right” might look like.

    To start pushing the rock up the hill, in emulation of Sisyphus, I would like to state something I have always had to bring up, whenever discussing small arms with the various enthusiasts for them, which is that the real problem is not creating the ideal weapon, but in first articulating how the hell you intend to use the things.

    The key point here is that there is no “best weapon”, no uber-waffe: The reality is that what might be the ideal weapon for one set of tactical intents is potentially totally unsuited for another. Thus, before we start going all a-Waltish fanboy over things, we must determine how we intend to use the damn things before we get all OCD on the details of the weapons themselves.

    So… One and all: What would an ideal path be, for small arms procurement? I say, determine tactics and operational intent, how you mean to use them, and then carefully consider who you will have manning your forces. A rifle perfectly suited for a Swiss militiaman defending a mountain pass against a totalitarian invader is going to look a lot different than a rifle meant to arm a Sudanese armed self-defense tribesman. What the one needs is necessarily different from the other, as the two parties will fight in very different ways.

    One of the abiding frustrations I’ve had, of late, is the typical focus most “authoritative” works on small arms have, which is on all the little details of production dates, mechanical fixes, and the like. A case in point is the set of books written by Folke Myrvang, focused on the German MG systems of post-WWI and the WWII era. He’s done magnificent work in documenting the guns, and all the little intricacies of their manufacture and production. He’s done magnificent work, but… There is a void in these works, one that I find incredibly frustrating–There’s none of the “Why” there. Why did the Germans design these guns the way they did? What was the tactical and operational framework within which they were supposed to work? These two books, which are acknowledged as being the most authoritative works on the MG34 and MG42 in existence, have only the most tantalizing references to the sort of things I’m trying to get at here: How did the Germans develop their tactics and doctrine, which these guns are almost perfectly suited for?

    I’ve got just enough background in this stuff, from extensive reading and so forth that I’ve mentioned before, but I cannot cite chapter and verse for actual sources. I know the stuff is out there, but I’ll be damned if I can even begin to figure out how to get at it. Mr. Myrvang has some tantalizing references to things that I saw in the references my informant in Illinois passed on to me, but there’s not a lot of meat there in the books he wrote discussing the whole question of “Why” when it comes to these guns.

    And, that’s the problem with all too much of our small arms world. The necessary thinking simply hasn’t been done–Go find an American Army officer, and point to the M16 or M4 that his troops are carrying, and ask him this: “Why was this weapon designed this way? What features of it support your tactics and operations? What deficiencies can you identify in how well it does that job?”. I can almost guarantee you that you will receive an epic “Deer caught in headlights of oncoming car” facial expression, because most of the US military has never thought these issues through, or even considered that they exist.

    I think it’s far past time that we changed that.

Comments are closed.