7.7x58SR Japanese casemouth sealant


I have a newly acquired 7.7x58SR Japanese round, with a brass case and GM FMJ bullet. this appears to be a ball round with lead cored bullet. Does the weakly coloured red casemouth selant have any significance?

Also, is there anything that gives a clue to where these unheadstamped rounds were made? This is a single round, so I have no box label.


For a ball round it would be pink rather than a weakly coloured red. Pink is the colour codes for WW2 Japanese ball rounds. The neck varnish did double duty to both water proof the round and ID the type of projectile. Other coloures the Japanese used were Black for AP, Green for tracer, Purple for explosive and Red for incendiary.



I would say this is pink, so it is ball. What was the name of the weapon this was used in? Wasn’t this the MG round and the rimless version the rifle round, or the other way round?



Rimless was rifle, Type 99. There are semi-rimmed and rimmed MG cartridges. Semi-rimmed is Type 92 (Army) and Rimmed is Type 89, 92, and 97 (Navy). But rimless were also used in Type 92, 99 and 97 MGs.

Confused? So is everybody else, including me. Don’t trust anything that I said above.

Jason. Any help???



Might be showing my ignorance here, but wasn’t the jap rimmed round identical to the 303Brit, or is my “old timers” desease kicking in again?


Wait, Wait!!! You can’t be confused yet!!! Let me confuse more… ;-)

Type 89 (Aircraft MG)
Type 92 (would also fire the rimless 7.7)
Type 97 (Tank MG)

Type 99
Type 2
Type 5

Type 1 (an “improvement” of the Type 92, it would not work with the 7.7x58SR)
Type 99 (designed for the 7.7x58 it would also work with the 7.7x58SR)

7.7x56mm Type 89
Type 89
Type 92
Type 97

Oh yeah, don’t forget about the 6.5x51SR

Type 38 rifle
Type 38 Short Rifle
Type 38 Carbine
Type 38 Paratrooper carbine
Type 44 Cavalry carbine
Type 97 Sniper rifle
Type 1 rifle

Type 3
Type 11
Type 39
Type 91
Type 96

So, anyone else think there were alot of Japanese supply SGTs and officers with headaches?

BTW, I am sure I missed some. Anyone else want to muddy the waters some more?

And yes, the 7.7 Rimmed was the 303, the Italians used it as well, so did the Finnish. Mostly in aircraft machinguns.


Yes, the Japanese built several licenced versions of the Lewis Gun, chambered in 7.7x56R (the metric name for .303 British), and the 7.7x58 was only used in bolt-action rifles, IIRC, so MOST of their MGs were in 7.7x58SR. I’m surprised Japanese quartermasters didn’t start the day by committing seppeku :-)


Add another one. We forgot 7.9x57mm…

Below is a photo of L-R 7.7x56mmR, 7.7x58mmSR, 7.7x58mm, 7.92x57mm, & 6.5x51mmSR

Now imagine you are under fire. Think fast, which one do you need…

Oh yeah, through personal experience, a 7.7x58mmSR cartridge does a bang up job of jamming a 7.7x58mm Type 99 rifle.


Well at least they had the good sense to standardize their pistol ammunition. No, wait. They had three different cartridges there too. Is it any wonder that they lost? There are some funny jokes about the japanese ammunition but I’m sure our moderators would delete me so I can’t tell them.



The Japanese T99 LMG used the 7.7x58 cartridge, it would not be able to feed or chamber a 7.7x58sr cartridge.


We can wonder at the problems of the Japanese Ordnance Supply sergeant, but was it that different from others? At one time or another in WWII, the German Military and Paramilitary establishment used:

Pistol Ammunition: 6.35mm, 7.65mm Brng, 7.65mm French Long, 9mm Kurz, 7.63 Mauser (SS had Schnellfeuer Mauser 912s) 9mm Para, 9mm Steyr, 9mm Largo (Astras from Spain), 9 x 25mm Mauser, and yes, in Norway, even .45 A.C.P. I have probably missed some. Saw a picture of a German soldier up on a railway right-of-way once, talking to some big shot outside of Warsaw and he clearly had the Austrian Holster of an 8mm Roth-Steyr pistol. Goering was captured wearing a Smith and Wesson .38 Special Military & Police Model Revolver, now in the West Point Museum I am told, that he purchased new from S&W’s German reps in the 1930s.

Rifles and MGS: 7.9 x 33mm, 7.9x57mm, 6.5 Dutch, 6.5 Carcano, 8x56R Austrian, 9.3 x 72R and 20 Ga (Luftwaffe survival drillings), probably 6.5 x 55 due to their involvement in Norway and possibly even 8mm Danish Krag, qnd who knows what else. They were lucky that so many of the European countries like Poland, Czechoslovakia and Yugoslavia had gone to the Mauser rifle in 7.9, as it eased their problem of ammunition supply for much of their captured weaponry, which they had to use.

We have not even considered the Volksturm here, who used just about everything and anything.

America had .30 Carbine, .30-06, .50 MG, 12 Gauge Shtogun (widely used in the Pacific by the USMC), .32 Auto, .380 Auto (both used by General grade officers and OSS operatives), 9mm Para (OSS again, and perhaps others), .45 A.C.P., .38 Special, .38 S&W, and again I have probably missed some. One could go on and on but the plethora of weapons and different calibers wasn’t especially unique to the Japanese. They probably led the way for different calibers among first-line, regular troops, but not even sure of that.

The Chinese in WWII and Korea probably had the Japanese beat. What a hodge podge of equipment. The NVA and VC the same, although I guess towards the end of the VN War, the NVA was getting more and more standardized on Russian caliber weapons. Even the US between Army, USMC, Navy Seabees, Air Force Personnel, advisors, etc. used about as many calibers in VN as they did in WWII.


Thanks everyone for your input, I can now put this round in the “Machine Gun” section of my records. Why use the rimless round for rifles and semi rimmed for machine guns?


I don


The British home guard of WW2 must also have used a huge number of calibres. They were issued US P-17 rifles in .30-06 from the USA, and .303 Ross rifles from Canada. Also French weapons from French troops evacuated from Dunkirk, and I believe any servicable machine guns off downed German aircraft (can anyone confirm/deny that?). They also used WW1 vintage .455 Webley revolvers with newly manufactured ammunition with jacketed bullets, as well as Sten guns. 12 Gauge shotgun shells with a single spherical ball or SG shot were also issued for use in privately owned shotguns. Some Parker Hale .22 Rifles with silencers were also issued for covert use againt German soldiers and tracker dogs in case of invasion. This brings us this list:

8mm Lebel
7.5mm MAS
.455 Webely
12 Gauge shotshell
.22 LR

Gatting ammunition arranged for whatever combination of these calibres a village home guard unit may have posessed must also have been a logistical nightmare.

As far as I know many other privately owned weapons in other calibres were used, so I’m sure we can safely add .45 ACP, .38 Spl, .38 S&W and .32 Auto Pistol to the mix as well.


Possibly a better way to have stated my above: the Japanese did it to themselves, everyone else did it because they had to.

Something that has not been mentioned and probably should be:
The 7.7 rimless and semi rimmed were originally designed to replace the 6.5 that was found to be lacking in stopping power. The Italians had the same idea with the 7.35 Carcano to replace the 6.5 Carcano. At least the Italians attempted to re-standardize on the 6.5 when they found themselves at war half way through a caliber change.

The 455 Webley revolvers were used extensively in WW2 and remained in use well into the 50


I know the Japanese did it to themselves, which I cannot understand. Japanese units probably ended up with significant stores of a particular kind of ammo, and no weapons to fire it (or vice versa). I am sure I would sooner carry a .455 Webley than 9mm. More stopping power, and no jamming. I did forget the .455 Auto, which I believe was still in use with air and naval units in WW2, never having been approved for ground use due to susceptibility to dirt (apparently it was too precisely made, so a slight speck of dirt could cause a jam). In the UK we often refer to the M-1917 Rifles as a “P-17” due to their connection with the British P-14 Rifle.


As far as the British Home Guard is concerned there were more calibres that those listed. When the American Committee for the Defense of British Homes sent their donations the British attempted to sift these into the more common calbres, but there were lots of odds and ends.

I have seen .351 Winchester M1907s (which the RFC also used in WWI), 44-40 Winchesters of various flavours, .38 Super and lots more.

Incidentally, the names of all the Americans who so kindly donated guns to Britain are all recorded in a file at our National Archives.



I had heard of American civillians donating guns to the UK before. Is my statement that they used machine guns from downed German aircraft true? It would make sense, as a servicable machine gun and a few hundred rounds of ammo would be a useful thing to acquire with imminent threat of German invasion. I suppose they would have also used pistols taken from any crew who bailed out or were captured from crash landed aircraft.


I’ve seen at least one picture showing someone in the Home Guard standing at his post holding onto a pintle-mounted MG17 (presumably taken from a downed German aircraft), so I’m sure they would’ve used whatever they could get.


I thought they would do that, it would be make sense really, when you needed any weapon you could get hold of.

Talking of taking machine guns from downed German Aircraft, there is a great book titled “The Machine Gunners” By Robert Westall. It is about a group of elementary school age kids in a ficticious town in England during WW2, who find an MG-15 machine gun attached to the wreckage of a crashed Heinkel He 111 in the woods. The sneak it home, and build their own bunker by the coast, complete with machine gun, hoping they can help repel the imminet German invasion.

When I was 8, there was a copy of this book on the shelf in my classroom at school, I began to read it. When the teacher discovered it contained a few swear words, I was given a very stern warning that I would be in “big trouble” if I showed it to any of the other kids or if she heard I had used any of the said words in school. Anyone who did read the original version of this post, that story was not correct as I couldn’t quite remember it.