“The Empire Strikes Back”: Recreating the Legendary .280 British (7x43mm) Round [GUEST POST]

The following is a guest article written for TFB by reader Tim about his efforts with his friend Paul to recreate the historical .280 British (7x43mm) round developed for the EM-2 and FAL rifles during the early pre-NATO rifle trials of the late 1940s. Enjoy!

 

This all started about two years ago when I happened to be lucky enough in a sealed bid auction to acquire a box of Radway Green 1970 production 7mm Mk. 1Z ammo for the Rifle No. 9 or EM-2 as it is known.

I posted online and was ridiculed for opening the box and letting some fellow cartridge collectors share in my good luck. Ah well, anyway a very good friend suggested we lobby to have an EM-2 built so we can fire the ammo. Common sense prevailed and I acquired 3 Remington 700 rifles with receivers long enough for a 50mm case and proceeded to find a gunsmith who would rebarrel them for us.

We chose to make our own brass as 20 Berdan primed cases (and that number was getting less every month) wouldn’t last long. Research led us to a UK gunsmith who had made one on a Ruger No. 1 a few years ago but he hadn’t really pushed the cartridge much beyond the minimum deer legal limit here of 1700 ft-lbs. We new that with good quality brass, modern primers, bullets and powder we could better the performance of the original round and its nemesis the 7.62 x 51 mm NATO beast.

I won’t go into history here, that’s being saved for a HBSA lecture and has frankly been covered elsewhere including very comprehensively on The Firearm Blog.

Anyway we found a gunsmith, reamers were ordered and money handed over for 2 rifles to be built.

Both were to have 20” barrels, partly because the short FN option was 20” and this showed problems with the improved .280/30 ammo and the fact that we would be using sound moderators which for some strange reason (perhaps the four to six inch extension helps) testing earlier with a 6.5 Grendel had shown a slight increase in muzzle velocity (mv) using a moderator.

With the rifles ordered we set about converting brass. I had originally wanted to use one manufacturers brass only but as it turned out we thought different types would allow a choice to be made later.

We are still converting brass as we speak and are currently looking at the option to use Lapua .308 Palma with its small primer pocket as again the Grendel testing has shown this to be a good option.

As a firearms dealer I have an account with Redding who supplied me with the dies needed for the work.

I should add that in addition to Paul who lives nearly 200 miles away, a former work colleague known as the Kiwi or Kiwi John assisted me greatly in my very steep learning curve of case forming.

Case Forming

No. 1: The Annealing

As I hadn’t done this before a trip to my Kiwi friends place showed me enough to get started and using kit from my local plumbers mate and Lyman I was able to anneal a few hundred likely suspects. Basically put the case in the case holder and spin it through a flame until the brass changes colour far enough down the body to allow the shoulders to be set back.

No. 2: Setting Back the Shoulder

I used my Redding Boss press for this, anything else I guessed may not be man enough.

This is the annealed brass in the press; you can see I have annealed almost half way down the case, no actual idea how far was needed at this point.

Below you can see the case protruding from the die, depth settings were hit and miss and dome visually against a factory round:

Here is a case formed on this occasion from a .243 case hence its weird double stepped neck shape:

You can see here a factory .308 case next to a .308 case that’s been set back and a factory round of .280/30. There is quite a bit of neck to trim.

No. 3: Neck Trimming

I chose to first do a coarse neck trim using a small pipe cutter from my local plumbers mate. This has now trimmed over 400 cases and cost me about £5. To speed things up I used the Lyman case holder in my drill:

This produced some good results:

No. 4: Neck Turning

I then had the drama of case neck turning and fine trimming. This was assisted by the Kiwi to start with and I am currently using a Lyman kit but may be looking at sending the next batch to a friend with a hobby lathe to get a level of uniformity which I seem unable to achieve by hand turning and I am sure is affecting the consistency of my test results (more of which later) and we know consistency is the true measure of quality.

I then test loaded some dummy rounds. This showed up a few problems which we had missed in the case forming process.

You can see above that the results of hand turning with a cheap drill isn’t great, I have a friend who is close to taking on the lathe work, I’m hoping this will give us the desired consistency.

Whilst all this was going on the rifles were close to being completed and test ammunition was sent so that the proof house could stamp the barrels. The factory ammo went missing and the proof house loaded up ammo using the prepared cases we sent. This showed up issues with steps we had missed out.

The cases on neck turning do seem to expand slightly, this seems to be a by-product of the brass turning and the cases need to be put through a full length resizing die and given a final polish before reloading.

I loaded my first batch with 120 grain bullets, this was down to load data being developed by a friend using the previous Ruger No1 data and quick load giving us some suggestions.

Powder selection was interesting as the original RG loading was not commercially available. We settled on a maximum load of 32 grains of Vihtavouri N133 (Vit N133) and selected a starting load of 30 grains and we would fire a couple of factory rounds to establish a base line. One of the issues here was we were firing without sound moderators as the thread adaptor hadn’t been ordered by me in time.

Some gratuitous rifle porn pictures, this rig is Paul’s and wasn’t used in the testing:

The rig below is mine built on a 22-250 receiver:

Below is the original August afternoon testing session:

Test rounds were 120 grain Sierra Gamekings

No group sizes were shot and the rifle scope was only adjusted enough to print on the paper for safety’s sake. The scope mounts were swapped for two piece ones before the next testing session when a moderator was available. Please see the part two updated with Stamford results for the testing that used 120 grain Barnes TSX bullets and 140 grain Hornady Interlock bullets:

These loads were also used to create a zero point with the final mounting option for the Schmidt and Bender 6×42 Scope. The picture below was shot with 120 Barnes TSX:

The main target was just something to aim at but at least forty rounds of 140grain loads printing here at 100 m. The loads were started using Vit N133 from 30.5 grains to 35.3 grains and Reloader 15 from 34.9 to 36.1 grains. We achieved the magical 2700 fps and 2000 ft/lbs, below is the narrative for an online post on the Army Rumour Service:

120 grain testing:

Factory 1970’s production test round 140 grain bullet was 2479 fps

The next four rounds (first of five failed to register on chrono) were:

30. grains N133 120 grain Sierra soft point
2485
2553
2520
2499
average of 2514 fps

30.2 grains
2561
2537
2471
2506
2532
average of 2521 fps

30.4 grains
2553
2513
2518
2521
2538
average of 2528 fps

30.6 grains
2567
2539
2550
2527
2529
average of 2542

30.8 grains
2566
2525
2492
2533
2509
average of 2525

31 grains
2551
2571
2541
2603
2576
average of 2568

31.2 grains
2592
2572
2591
2599
2622
average of 2595

31.4 grains
2619
2625
2655
2678
2612
average of 2637

31.6 grains
2621
2594
2612
2630
2638
average of 2619

31.8
2644
2637
average of 2640

Variances could be due to neck tension of different cases made this year, creating a true uniform case is a real challenge. We ran out of time to make the full amount of ammo for testing so we had hoped to go to 32 grains and then start with a 140 grain bullet. Plus we didn’t have a moderator with that thread available.

The first thing I did was to fire 16 rounds of 120 grain bullets at maximum load of 32 grains of N133 which showed an average of 2619 feet per second and a muzzle energy of 1828 foot pounds. The spread was 129 feet per second at this load.

I then commenced to shoot the Barnes TSX 120 grain bullets also using a maximum load of 32 grains of N133. This gave an average of 2697 fps and a spread of 113 fps giving a muzzle energy of 1938 foot pounds.

I then started with the 140 grain bullets, again all sierra game kings in 2/10ths of a grain steps from 30.5 to 32.3 grains of Vit N133. Muzzle energy is calculated using Hornady’s online calculator

Results were as follows:
30.5 grains, average MV 2493 fps ME 1932 foot pounds.
30.7 grains average MV 2504 fps ME 1949 foot pounds
30.9 grains average MV 2556 fps ME 2031 foot pounds
31.1 grains average MV 2475 fps ME 1904 foot pounds (not sure why this happened, see note below)
31.3 grains average MV 2529 fps ME 1988 foot pounds
31.5 grains average MV 2539 fps ME 2004 foot pounds
31.7 grains average MV 2604 fps ME 2108 foot pounds
31.9 grains average MV 2537 fps ME 2001 foot pounds (as above????)
32.1 grains average MV 2610 fps ME 2118 foot pounds (picked up again)
32.3 grains average MV 2627 fps ME 2145 foot pounds

We moved onto using Reloader 15 powder next starting at 34.9 to 36.1 grains in 2/10ths of a grain step, results were:
34.9 grains average ME 2631 fps ME 2152 foot pounds
35.1 grains average MV 2559 fps ME 2036 foot pounds
35.3 grains average MV 2527 fps ME 1985 foot pounds
35.5 grains average MV 2605 fps ME 2109 foot pounds
35.7 grains average MV 2700 fps ME 2266 foot pounds
35.9 grains average MV 2665 fps ME 2208 foot pounds
36.1 grains average MV 2699 fps ME 2264 foot pounds

I haven’t actually explained the dramas we went through, unfilled reamer orders, invoices recharged, lost ammunition, stuck cases, range closures, land access and a big clock ticking which means that soon my friend Paul will be leaving the UK for an extended stay overseas and I will have to carry on load development without him.

A footnote to explain and disclaim, firstly the disclaimer:

All of the data we have shown is from testing, dies were Redding, case prep was Lyman, RCBS provided the electronic scales and powder throw and none of this data is necessarily going to be reproduced in any other rifles. As for Rifles, used Remington 700’s were used and rebarrelled by Riflecraft of Norfolk. Rifles were subjected to proof testing at the London Proof House.

Background: Paul is a great personal friend of mine and we have been shooting for many years. I started as a 12 year old in Cornwall and I joined the Army aged 16 from school serving about ten years as a regular and reservist until a car crash finished that fun. I am also a registered firearms dealer and member of the Historical Breech Loading Small Arms Association.

Paul served as an NCO and instructor with the RAF Regiment.





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 nathaniel.f@staff.thefirearmblog.com.


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  • PK

    140gr at nearly 2500FPS… I can’t see why the 7.62x51mm is seen as a let-down, in comparison. 147gr at 2700FPS, M80 ball, seems superior from a kinetic standpoint.

    I’d probably understand if I had both cartridges in hand and a variety of the ballistics sheets in front of me, but I suspect where the .280 British would have really shined is with VLD bullets, at great distance. In other words, exactly what many Western armies use 7.62x51mm for in the DMR role!

    • Vitor Roma

      The 7mm would have a clearly superior BC, and it’s supposed to be a bit less powerful than the x51, since it means less recoil, more control.

      • PK

        Fair enough. As I said, if I had the ballistics charted in front of me, I’d probably see the wisdom.

        With the better BC in mind, if the .280 British had been the choice instead of 7.62x51mm, it would likely be superior for the role into which we’ve shoehorned the 7.62x51mm these days.

    • ostiariusalpha

      Don’t forget that these velocity numbers are from a bolt gun, a gas-operated rifle would lose some of that MV. M80 gains about 75-100ft/s in a 24″ Rem 700 versus the M14 rifles 24″ bbl that is the source of the 2700ft/s that you’re quoting.

      • The M14 has a 22″ barrel. With M59 Ball, it is specced at about 2,800 ft/s with a 150.5gr bullet.

        • ostiariusalpha

          My whole comment is a mess, I should have just deleted it. 😧

          • iksnilol

            YOUR COMMENT IS BAD AND YOU SHOULD FEEL BAD.

            [Zoidberg noises]

          • ostiariusalpha

            I basically read all of your comments as if you sound like Zoidberg.

          • iksnilol

            WHOOP WHOOP WHOOP!

            [Scuttlying Away Intenisifies]

    • Anonymoose

      I’d rather go with 7mm-08.

      • Quasimofo

        Yes, flinging 140 grainers @ ~2,800 fps. Gotta use ~165gr to get similar SD & BC in .308, and the 7-08 will have ~90% of the KE with ~80% of the recoil energy. Great deer medicine.

      • Mick Kelly

        Anonymoose, you’re missing the point here, it’s all about reconstructing the .280 British.
        Yes there are other similar calibres but Tim’s experiment shows exactly the opportunity that was missed by the US and the UK when NATO was being formed.
        It does raise the point that had we adopted the .280 British in NATO, would there have been the need for the .223 / 5.56mm calibre in the 1950’s & 1960’s?

        • Form Factor

          Literally the only reason why 5.56×45 doesnt perform as much as it actually could is its short nose ogive lengt, with a better Form Factor it would have enormous better performance.

          And the .280 British is even tough better than 7.62×51 still a bs round.
          Hilariously slow (trajectory, wind drift, and supersonic range sucks). Still verry unoptimized aerodynamics… ,far away from actual high performance.
          And damn heavy which results in much less rounds, far less fire superority, and shorter time beeing able to stay in combat. Also due to p=m x v while KE=1/2m x v² TOTALLY uneeded Recoil for absolutly no reason.

        • Anonymoose

          No, and there would be no 7mm-08 either, and we probably would have adopted the AR10 in .280 instead of the M14.

    • iHAL

      Not everything is purely one shot kinetic.

      Ideal cartridge is an engineering problem. Requirements should stem from likely use cases and likely the final best fit is not going to be “best” at anything.

    • iksnilol

      Less recoil, better range.

      • Logic

        No, thats way too comlicated, go away with your math! Its all about knuckduwn powah.

  • Audie Bakerson

    No gel test?

  • glenn cheney

    Creedmore anyone?

  • DonaldJump

    I AM THE SENAT …Nathaniel… YOURE FIRED!!

    • Hilarious. You need more upbotes.

      • DonaldJump

        Rather dont say one word anymore! because i hav thee tepes!!!

  • FormFactor

    Cool reconstruction. From a practical standpoint the velocitys really aren’t that great, just results in worse trajectory, wind drift, short supersonic range, the cartridge is often overestimated. 7mm is just to much, even 6.5 (6.7mm) is too heavy to push it at any adequat velocitys without stupid recoil (and weight). Smaller diameters with better Form Factor at good velocitys will perform better. But damn cool work to reconstruct the .280 British, really enjoyed the long Article.

    • MSG1000

      Agreed, but as someone who’s still trying to learn some science basics about ballistics is it everything above 6.5mm, in your opinion, that won’t mathematically work out for small arms or are there larger sizes that work out?

      • Form Factor

        Exactly. For Infantery Smallarms you should never go over a certain diameter, because things are just getting worse, and simply unsuited for its task.

        For a modern round 3000fps should basicly be standart, you have no reason to go under it because the large expense in trajectory, wind drift, supersonic range, and also KE/mm² (less diameter with more velocity means higher penetration). Also a high velocity results in a lighter cartridge for the same energy.

        So than you should think about cartridge Energy, for the use of Infantery you dont want high recoil (slow follow up shots), also a lot of rounds for fire superority (supression) and staying longer in combat. Current 5.56×45 standart is 1684J (16″) to 1852J (20″).
        If you use light cases you can increase energy with far less drawbacks, but i dont think its smart at all to go over 2400J for Infantery Smallarms.

        Range should much rather be reached by aerodynamics, not energy, with a good form factor you make extrem savings in recoil and weight.

        “6.5” (6,7mm) as diameter as example, with the said 3000fps is out of this logical area already. Its EPR projectile is about 108 to 123grain = 2927 to 3333Joule!
        The further problem is that Recoil is p=m x v, while Kinetic Energy =1/2m x v.
        So a lighter projectile for the same energy, has much less recoil.

        Such a round from a light Rifle/Carbine in urban combat will have extremly negative effects on % hit propability, and makes follow up shots slower (=also less efficient supression!). With EPR projectiles and opponents often showing a verry small silhouette (gun+head) but also vital, a hit is lethal anyways, you just cant make it magical more dead. Also with normal hits EPR’s totally rip arms, legs, organs, lungs, neck appart, at that distance a bit energy dont make any practical diffrence.

        So the only reason why 6.5 is so overestimated is its commercial available rounds, that simply have a longer ogive lenght to diameter ratio than 7.62×51 and therefore have comperable better ballistics. But that ofcourse doesnt mean the diameter is any magical, most of them are extremly far from any actual performance boundaries. And it by far doesnt mean its any bit optimal for Military Infantery Smallarms.

        • Form Factor

          *KE=1/2m x v² , i forgot the ^2

        • iksnilol

          Got you, we need 4.7mm telescoped polymer case rounds.

          • Form Factor

            Oh please no.

          • iksnilol

            Should be able to outclass current 5.56 if you used optimized projectiles. And you’d have ridicilous weight savings.

            + you could potentially rechamber pistols to it as well for even more weight savings.

          • ostiariusalpha

            Forget the weight savings, a 4 gram 5mm EPR bullet going 1100m/s would be a literal killer app for a new weapon/ammo platform.

          • Form Factor

            3608,924fps with 2431J = PEW!

          • iksnilol

            No, never forget the weight savings.

          • A 4g 5mm EPR would be a heck of a trick by itself.

          • ostiariusalpha

            Hahaha, perhaps not quite as tricky as getting a modified .22 Nosler to go 2900ft/s with a 70gr bullet in a 14.5″ bbl, but a little bit of a challenge. Getting the weight balance correct is the key point. https://uploads.disquscdn.com/images/b58505a2a300362fd203df2de1cb66d7a396a9e740782fc7dbe120444faafaaa.jpg

          • Form Factor

            As said before, rather use a bit lighter round than brass 5.56×45, but with much better performance. You can have a supersonic range of 1200m, excellent penetration, lethality, still light recoil, excellent energy retention at range, etc. That also allows a single round system with insane logistic benefit, and still has maximum practical engagement range.

            4,7 has extrem restrictions, its gyroscopic effect is so minimal that you just cant reach a good Form Factor for Aerodynamics. It has problems with its tiny bore volume. Its just too small.

            And using Rifle ammo from a pistol… my god the muzzle blast, flash, and propellant waste.

          • ostiariusalpha

            I think iksnilol meant using the same bullet, not the same cartridge.

          • iksnilol

            Yeah, but if you have a much lighter round than 5.56 then you can both enjoy somewhat improved performance whilst enjoying having waaay more of it. Y’all are obsessed too much with improving 5.56s perfectly good performance that you forget what made it so great in the first place: Being lightweight and easy to shoot.

            Meh, blast would be somewhat greater, but that’s more than weighed (heh) up for by greatly simplifying logistics. And who cares about propellant waste if its a round primarily meant for rifles (which are getting optimized for shorter barrels all the time as the trend indicates).

        • MSG1000

          Thank you for the detailed reply!

          Lots of neat information for me to dig into.

          • Form Factor

            No problem, glad i can help, i can add you in skype if you have it so you can ask me anything technical at any time.

  • Bambibasher

    Thanks for the comments folks, the whole thing has been a trial of willpower over common sense but we are really only just started. Paul and I work full time and have done this work 200 miles apart with e mails and the occasional late night session fuelled by snakebite. There is a long way to go yet and we have only just started to see the potential of this cartridge.
    Matched to a good bullet with modern powders we have miles of improvements left to make

  • Brian Fulmer

    Or a nice heavy 173 gr bullet in M1 Ball that then FAR exceeded the safe area of the Nat’l Guard ranges in the 20’s and 30’s. AND was extremely unpleasant to shoot in Springfields – my Grandfather loathed the “shoulder breaker” ammo drawn for the California Guard training from Nevada “war stores”. The 6mm argument is hard to contend with, this despite I don’t own a single firearm with that bore diameter and shoot 175 gr SMK in 30-06 in my “too old for High Power matches” Garand. The 280 Brit was unfit for the task, either too slow to make sense or too fast to be an improvement on the 762 NATO. The over-reaction of moving to .224 caliber projectiles does not validate .28 caliber as the correct alternative. .24 caliber is likely the 9mm Para of rifle cartridges.

  • Paul

    Neck reaming is another way to reduce the thickness of the reformed case necks. I had good luck doing this with a batch of free 7.62×51 military cases to fit a tight 308 Winchester chamber. Neck reamer and die from RCBS produces very consistent neck thickness.