WesWorld

Quoted from "Hood"

7.62mm FN SLR40
A Fabrique Nationale developed gas-operated semi-automatic rifle which was designed as a common UKN rifle, although only Belgium and the Netherlands accepted the 7.62mm round, SLR40s for the Kongo are chambered for the Swiss 7.5mm G11. Dieudonne Saive, Fabrique Nationale's chief firearm designer, experimented with a number of recoil-operated rifle designs in the early 1930s and he took out patents on his work in 1936 and prototypes appeared in 1937. A version with a 5-round magazine was developed for field trials in 1938, but production models have a 10-round capacity.
Calibre: 7.62x51
Action: gas-operated, tilting bolt
Length: 1.16m, 0.59m barrel
Weight: 4.31 kg
Magazine: 10 round fixed box magazine
MV: 840m/s
ROF: 600 rpm (cyclic)
Effective range: 400-600m depending on sights

You need to double-check the specs on this one, Hood. You've listed your standard caliber as 7.62x51, which is an American 1950s round. Also, I question the rate of fire. This is a semi-automatic rifle, so that sort of rate of fire is completely unreasonable and unobtainable. Even quoting a rate of fire is somewhat misleading...

It is noted as the cyclic ROF - which is standard parlance for measuring how quickly the mechanism works. It's purely nominal. Though I agree, the 7.62x51mm round is definitely a 1950s creation in OTL.

Other than that, I wish this had been available when the Philippines was shopping for a new rifle.

You also need to check the armament on the T20 tank - it should be a 75mm/L34, not a 75mm/L53.

This is what I based the SLR40 on, Kirk's very sketchy history of the Dutch version;

Quoted

With the advent of semi-automatic rifles, there was a push by some in the armed services to adopt a round between the two, the Swiss 7.5mm G11. This was compounded by the Belgian army pushing the Dutch to adopt their 7.62mm for commonality should the Germans invade. While both rounds were found very satisfactory, senior staff and the politicians were loath to dispense with the 7.92mm ammunitions stocks so recently bought. The events in Lithuania showed the 7.92mm in an excellent light, and doomed reformists efforts. In the same time period the Kongo was seeking to arm its independent army, recently separated from the Dutch. Heeding the lessons the Dutch had learned, and spurning the Belgian round, the Kongo adopted the Swiss 7.5mm G11. The result was the dawn of 1937 saw the fiscally minded Kongo adopt the proven Swiss Schmidt-Rubin rifles with the 7.5mm G11 round, while the Belgians keep their 7.62mm for the projected FN Self-Loading Rifle. The Dutch found themselves in an awkward situation. The semi-automatic rifle trials had not found an immediately purchasable semi-automatic; instead further development had led to the satisfactory ZH-37. Negotiations in late 1936 to arrange sufficient production led to a license to FN, which needed to tool up. However, having delayed rifle purchases and sold off surplus rifles while conducting the semiautomatic rifle trials, there was a shortfall of rifles to equip the newest territorial units, resulting in the reissue of the elderly 6.5mm Mannlicher rifles for the new Territorial units. As ZH-37s displaced the older Mausers with the Dutch Marines, and later the Army, the surplus rifles could be refurbished and used to bring the Territorial units up to standard.

Here, Kirk specifically mentions 7.62mm rather than 7.65mm as the Belgian calibre for the new Self-Loading Rifle. Therefore I assumed a 7.62x51 would be the closest thing in Kirk's mind. I'm no small arms expert so I defer to those who know more about this stuff as to why the Belgians wouldn't use a 7.62x51.
I must admit it seems odd to me for the Belgians to switch given the marginal difference. So I have some questions/ proposals I'd like feedback on.

1) Is it feasible for the Dutch to use their 7.92x57 in the SLR40? (I'm assuming not)
2) Given I know everyone is waiting for the FN FAL, given Brock wants it in 0.280 (7x43) and that the Belgians were enamoured with the British 0.280 concept alongside the EM-series etc., is there a case for making the SLR40 for the Belgians and Dutch in 7x43 now rather than making that switch in a few years time when the FAL comes out?
3) If 2 is not feasible is it best just to stick with the 7.65x53 Mauser for now for Belgium?
4) If the answer to 1 is no and the answer to 3 is yes, then what's the best move for the Netherlands to avoid a double calibre switch when the FAL comes out?

Quoted from "Hood"

This is what I based the SLR40 on, Kirk's very sketchy history of the Dutch version;

Quoted

With the advent of semi-automatic rifles, there was a push by some in the armed services to adopt a round between the two, the Swiss 7.5mm G11. This was compounded by the Belgian army pushing the Dutch to adopt their 7.62mm for commonality should the Germans invade. While both rounds were found very satisfactory, senior staff and the politicians were loath to dispense with the 7.92mm ammunitions stocks so recently bought. The events in Lithuania showed the 7.92mm in an excellent light, and doomed reformists efforts. In the same time period the Kongo was seeking to arm its independent army, recently separated from the Dutch. Heeding the lessons the Dutch had learned, and spurning the Belgian round, the Kongo adopted the Swiss 7.5mm G11. The result was the dawn of 1937 saw the fiscally minded Kongo adopt the proven Swiss Schmidt-Rubin rifles with the 7.5mm G11 round, while the Belgians keep their 7.62mm for the projected FN Self-Loading Rifle. The Dutch found themselves in an awkward situation. The semi-automatic rifle trials had not found an immediately purchasable semi-automatic; instead further development had led to the satisfactory ZH-37. Negotiations in late 1936 to arrange sufficient production led to a license to FN, which needed to tool up. However, having delayed rifle purchases and sold off surplus rifles while conducting the semiautomatic rifle trials, there was a shortfall of rifles to equip the newest territorial units, resulting in the reissue of the elderly 6.5mm Mannlicher rifles for the new Territorial units. As ZH-37s displaced the older Mausers with the Dutch Marines, and later the Army, the surplus rifles could be refurbished and used to bring the Territorial units up to standard.

Here, Kirk specifically mentions 7.62mm rather than 7.65mm as the Belgian calibre for the new Self-Loading Rifle. Therefore I assumed a 7.62x51 would be the closest thing in Kirk's mind. I'm no small arms expert so I defer to those who know more about this stuff as to why the Belgians wouldn't use a 7.62x51.
I must admit it seems odd to me for the Belgians to switch given the marginal difference. So I have some questions/ proposals I'd like feedback on.

1) Is it feasible for the Dutch to use their 7.92x57 in the SLR40? (I'm assuming not)
2) Given I know everyone is waiting for the FN FAL, given Brock wants it in 0.280 (7x43) and that the Belgians were enamoured with the British 0.280 concept alongside the EM-series etc., is there a case for making the SLR40 for the Belgians and Dutch in 7x43 now rather than making that switch in a few years time when the FAL comes out?
3) If 2 is not feasible is it best just to stick with the 7.65x53 Mauser for now for Belgium?
4) If the answer to 1 is no and the answer to 3 is yes, then what's the best move for the Netherlands to avoid a double calibre switch when the FAL comes out?

The Wikpedia article for the SAFN49 indicates that the OTL Belgian SAFN49 could be chambered for the standard Mauser 7.92mm round - as well as others. I see no reason why it could not be - might have a bit more kick to it but no worse than the OTL Garand. And since it could also be chambered for the 7.65mm round, it would seem as if the Belgians and Dutch could both have their cake and eat it too.

Well that reference is to the initial prototypes that led to the SLEM-1, which also used an 8mm, so I agree its possible.
I'll stick with the 7.65 and 7.92 and 7.5 variants for Belgium, Netherlands and Kongo respectively.


I've edited the T-20 too, for some reason I assumed the standard FRC gun had been fitted.

I'll need to answer more fully when I get home and am not on my phone, but I think the 7.65x53 will work just fine in the SAFN. 7x43, by contrast, will end up requiring a lot of redesign...

Quoted from "Hood"

Here, Kirk specifically mentions 7.62mm rather than 7.65mm as the Belgian calibre for the new Self-Loading Rifle. Therefore I assumed a 7.62x51 would be the closest thing in Kirk's mind. I'm no small arms expert so I defer to those who know more about this stuff as to why the Belgians wouldn't use a 7.62x51.

Basically, the historic 7.62x51 is a shortened version of the American .30/06 round (7.62x63mm in metric). It's not an unreasonable caliber to put together from scratch in this era, but the Belgian 7.65x53 round is going to be pretty much identical in dimensions, as near as makes very little difference. (In referring to rifle ammunition, often some informal rounding of numbers is introduced - so the German 7.92x57 is often just called 8x57 or flat out "8mm Mauser".)

Quoted

I must admit it seems odd to me for the Belgians to switch given the marginal difference.

If the round was obsolescent (for instance, if it was rimmed or had a round-nosed bullet), then a replacement might not be unlikely, but the Belgian 7.65x53 appears to be the historical 7.65x53 Argentine Mauser round - which I don't believe is an obsolete cartridge at all. So yes, a switch of that nature, unless for very obvious improvements in supply availability, is just a waste of time and resources. While I hesitate to suggest it, Kirk's repeated mentions of a 7.62mm round may just be a propagating typo or confusion about the identity of the rounds. ?(

Quoted

1) Is it feasible for the Dutch to use their 7.92x57 in the SLR40? (I'm assuming not)

Yes. The historical SAFN originally designed for 7.92x57, after all. It was then oversized slightly for .30/06, and downsized for 7.62x51 NATO, as well as other calibers. Basically, you can presume that anything within 6-7mm case length of the original may be accommodated, except in the cases where the action isn't strong enough to start with. It's a very fine line to walk.

Quoted

2) Given I know everyone is waiting for the FN FAL, given Brock wants it in 0.280 (7x43) and that the Belgians were enamoured with the British 0.280 concept alongside the EM-series etc., is there a case for making the SLR40 for the Belgians and Dutch in 7x43 now rather than making that switch in a few years time when the FAL comes out?

It could be done, but I wouldn't. Not really worthwhile, in my opinion.

When the EM-2 comes out, I'm going have to have a nice long thinking session about what I'd like to do with the Irish small arms. The .280 will be impressive in a semiauto rifle, but I'm generally of a school that prefers larger and more effective rounds. For example, if you offered me the choice of a 7.62x39-chambered AK47 and a .30/06-chambered Garand (or SAFN)? No question, I'd choose the Garand or the SAFN. I kinda run hot and cold on the .280: some days I love it, and some days I'm not sure why I'd want it...

Must admit - I'm seriously considering whether or not I'd want to buy SAFNs for the Irish Army. It's one of my all-time-favorite rifles.

Quoted

3) If 2 is not feasible is it best just to stick with the 7.65x53 Mauser for now for Belgium?

I think that's the most reasonable course, honestly.

Quoted from "Hood"

Well that reference is to the initial prototypes that led to the SLEM-1, which also used an 8mm, so I agree its possible.

I believe the 8mm cartridge the original SLEM-1 used was not in fact 8x57 Mauser, but 8x33 Kurz - the round used in the StG-44.

Also, I find it amusing and curious that Belgium's apparently stolen the Land Rover for the Dutch. :whistling:

That's very helpful. I'll stick with the 7.65 and 7.92 and 7.5 variants for Belgium, Netherlands and Kongo respectively.

Yeah, I might change that picture. The Land Rover will be making an appearance this year in prototype form, in no way should you consider the Minerva M20 a clone of that vehicle. I had hoped it might look just different enough, but it doesn't.

Posting this here as the nearest relevant thread.
I know Brock has been waiting for this moment!

7.62mm FN FAL
FN FAL will begin testing prototypes of their new gas-operated rifle, the FN FAL during 1948 with an aim to have the first production versions ready to enter service in 1951.
The FAL has a gas-operated action, driven by a short-stroke, spring-loaded piston housed above the barrel and the locking mechanism is a tilting breechblock. To lock, it drops down into a solid shoulder of metal in the heavy receiver. The gas system is fitted with a gas regulator behind the front sight base, allowing adjustment of the gas system in response to environmental conditions. The piston system can be bypassed completely, using the gas plug, to allow for the firing of rifle grenades and manual operation. The FAL's magazine capacity ranges from 20 to 30 rounds. In fixed stock versions the recoil spring is housed in the stock, while in folding-stock versions it is housed in the receiver cover, necessitating a slightly different receiver cover, recoil spring, bolt carrier and a modified lower receiver for the stock. FAL rifles can be manufactured in both light and heavy-barrel configurations, with the heavy barrel intended for automatic fire as a section or squad light support weapon. Heavy barrel FALs are equipped with bipods. The FN FAL has relatively light recoil, due to the gas system being able to be tuned via a regulator, which allows bleeding of excess gas to decrease recoil. In full automatic mode, however, the shooter receives considerable recoil and the weapon climbs off-target quickly, making automatic fire only of marginal effectiveness.

Calibre: 7.62x53 Mauser
Action: gas-operated, tilting breechblock
Length: 1.1m, 0.53m barrel
Weight: 4.45 to 5.15 kg
Magazine: 20-round magazine
MV: 823m/s
ROF: 600 rpm (cyclic)
Effective range: 800m depending on sights
Sights: iron sights

This thread is relevant to my interests...

Quoted from "Hood"

Calibre: 7.62x53 Mauser

Do you mean 7.62x57 Mauser?

That's a heftier cartridge than most FALs were ever chambered for. It was originally designed for .280 British, and on American insistence was sized up to 7.62x51 NATO... which is smaller than 7.62x57 Mauser.

Sorry, that's my typo/ mistake. I've gotten my cartridges well and truly muddled up here.

The SLR40 in Dutch service uses the 7.92x57 IS, the Belgians and Kongolese are using 7.65mm and 7.5mm.
A 7.92mm isn't going to work with the FAL, so I think now's the time to seriously start thinking of what should replace the 7.92mm.

FN will be making a .280in (7x43) FAL chambered for the British round.
My preference would be for the Dutch to adopt a 7.62x51. Or it might be easier to use the Belgian 7.5x53 (based on OTL Argentine Mauser which in WW Argentina doesn't use!!, perhaps in WW we'd better call it Belgian Mauser?).
Another choice is to buy into the 7x43 club, which I know you're hot and cold about.
I guess is depends what experiences from Ubangi-Shari have shown to be preferable, I guess most of the action there would have been fairly close-range with emphasis on rapid fire than accuracy in some situations but then its unlikely that the SLR40 will be fully replaced for probably another decade so there will be a mix of lighter and heavier calibres for some time.

Okay, that's what I figured...

Quoted from "Hood"

My preference would be for the Dutch to adopt a 7.62x51.

...except, due to the prior development of US small arms, I don't think the 7.62x51 NATO round will likely see the light of day. Hrolf had the US adopt the .276 Pedersen (which is a cartridge very similar in size and recoil to the 7.62x51). So the US has no reason in Wesworld to invent the 7.62x51, nor is there any NATO pressure to foist it off on the NATO allies. While .276 Pedersen might not be a bad idea for a larger FAL, the Pedersen round has a significant taper (it's much wider at the back than the front), and so all your magazines will look banana-shaped; and from what I understand, the .276 Pedersen does funky things in machine guns.

Quoted from "Hood"

Or it might be easier to use the Belgian 7.5x53 (based on OTL Argentine Mauser which in WW Argentina doesn't use!!, perhaps in WW we'd better call it Belgian Mauser?).

7.65x53 Argentine isn't necessarily a bad choice. It'd work tolerably well. In some places, it is actually called 7.65 Belgian, for what it's worth. A bit heavier than I'd want to shoot in a full auto (or semi-auto) rifle, but you can probably get away with it in most cases.

Quoted from "Hood"

Another choice is to buy into the 7x43 club, which I know you're hot and cold about.

That'd work too.

One alternative that you haven't mentioned here is the 6.5x51 FAR, which is similar in some ways to the 7.62x51 NATO and the .276 Pedersen. It's a thoroughly modern round (1935) which is still large enough to be used for machine guns (France, Atlantis, and Russia all use it for their light machine guns), small enough to be used in a fully-auto battle rifle (barely), and has some very good accuracy due to its high MV. It's also used by no less than three of the Great Power armies, including the world's second largest. That means this round is probably the most widely-used in the world (perhaps excepting the 8mm Mauser, and possibly not even that).

Quoted from "Hood"

I guess is depends what experiences from Ubangi-Shari have shown to be preferable, I guess most of the action there would have been fairly close-range with emphasis on rapid fire than accuracy in some situations but then its unlikely that the SLR40 will be fully replaced for probably another decade so there will be a mix of lighter and heavier calibres for some time.

Yes, that experience is definitely going to skew the Dutch view of things.

If the Dutch are more interested in rapid fire at closer ranges as opposed to aimed fire at intermediate ranges, then I'd say go with the .280. Just keep in mind that .280 is going to be a pretty poor companion round for squad machine guns, therefore you'd need to retain another caliber for that.

If the Dutch are more concerned about aimed fire at intermediate ranges, and having something also suitable for MGs... then I suggest the 6.5x51 FAR (with 7.65 Belgian as the fallback option).



Regardless of what options you choose for yourself, the Irish Army would like to buy five FALs in .280 Brit and five FALs in 6.5x51 FAR for evaluation purposes. The French would also like to buy twenty-five FALs in 6.5x51 FAR for evaluation.

That's most helpful Brock and has given me something to mull over.

I don't suppose anyone has ever done an audit of exactly which nations are using which cartridges? I think it would be wise to follow the biggest users to make the FAL as exportable as possible.

Britain seems to be alone in the .280 choice at the moment, no idea if Canada or Australia will ever adopt it or not, and Britain is using it in the new TADEN LMG, which as you say is probably too light for such work but then there will be plenty of older .303in Vickers K LMGs and the heavier .303in Vickers HMGs about a for long period to come yet. With the EM-2 I don't see any British need for the FAL at this stage but British Commonwealth nations might see the benefits of the .280 with the cheaper FAL.
Argentina has stuck with the 7.92x57 in its STPR-36 Radichkov, but those were ordered 9 years ago now and probably something lighter and more modern will be required. The FAL would be a good choice for them in a new calibre.
The Belgians will stick with 7.65x53, they will be buying the FAL.
Will the Kongo keep the Swiss 7.5mm G11? Economics would probably dictate so.

Germany has two rifle and one pistol cartridge in service, detailed here.

The technical issues uncovered in the K37 semi-automatic rifle and the poor ballistic performance of the 7x40mm cartridge has led the Heer to progressively remove the K37 and its ammunition from front-line service and most remaining rifles are in store. While foreign developments are still followed with interest, the scandal surrounding the premature adoption of the 7x40mm round had made the Army Ordnance Office wary of anything but the tried and battle-tested 8mm Mauser (7.92x57mm) round.

Quoted from "Hood"

That's most helpful Brock and has given me something to mull over.

You're welcome; glad I could help. :)

Quoted from "Hood"

I don't suppose anyone has ever done an audit of exactly which nations are using which cartridges? I think it would be wise to follow the biggest users to make the FAL as exportable as possible.

I put together a quick table and I'll upload it when I get home.

One thing to keep in mind is that, while a lot of the countries in the list use 7x57 or 7.92x57 Mauser (remember the two cartridges are distinct), this doesn't mean that the FAL should be chambered in either of those two cartridges. (A FAL in 8mm Mauser would be bloody heavy and nigh-uncontrollable in full auto mode.)

Quoted from "Hood"

Britain seems to be alone in the .280 choice at the moment, no idea if Canada or Australia will ever adopt it or not, and Britain is using it in the new TADEN LMG, which as you say is probably too light for such work but then there will be plenty of older .303in Vickers K LMGs and the heavier .303in Vickers HMGs about a for long period to come yet.

Yes, and 0.303 is - aside from being rimmed - a good enough round for a long while yet, particularly in machine guns.

I don't really know much about the TADEN LMG, but as a squad automatic weapon (SAW) it's going to represent a level of development that, in some ways, really didn't happen in real life until the 1970s-80s.

Too light for the work? Well... it all depends upon your point of view and your objective. A SAW chambered in .280 will give quite a lot of nice firepower at the squad/section level. But, on the flip side, it will lack a bit of flexibility in engaging lightly armoured vehicles or infantry at long ranges. Also, I'm not sure whether or not the .280 can be belt-fed or not. (Probably can, but I'm uncertain enough to make note of it.)

Quoted from "Hood"

With the EM-2 I don't see any British need for the FAL at this stage but British Commonwealth nations might see the benefits of the .280 with the cheaper FAL.

Agreed. As I've mentioned before, Ireland is interested in an eventual small-arms upgrade - but it's obviously a very expensive and radical thing for the Irish to convert over all of their small arms to a new caliber, and Dublin is worried about the .280's compatibility for machine guns. Adopting .280 would likely mean that they'd need to either keep 0.303 in stock for the Breire machine guns, or find a new machine gun. The rest of the Commonwealth would be in that same boat, unless they adopted something like the TADEN at exactly the same time.

Quoted from "Hood"

Will the Kongo keep the Swiss 7.5mm G11? Economics would probably dictate so.

Probably; and in the 1950s the Swiss will probably come out with a 7.5x55 battle rifle (the SIG SG510) that Kongo could buy. The Swiss, due to their "sharpshooter mentality", really resisted moves toward smaller calibers, and any loss of accuracy in favor of rate-of-fire was really, really frowned on. So Kongo (and Bulgaria) probably don't need to worry about a caliber change until at least the 1980s. :)