7.62 x 3X mm family of Subsonic loadings


#1

What is the story about these rounds? The 2000 dated examples are 7.62 x 37 and are so headstamped (has both RG and HK headstamp markings). The bullets differ only in the moly(?) coating. The 7.62 x 34 loading has a ‘R-P 221 Fireball’ headstamp. By x-ray, they appear to be loaded with similar projectiles. I’m assuming that the ammo is of British manufacture and the weapon is by HK - i.e. a joint venture that has since come to pass.

In the following picture is a ‘standard’ 7.62 x 37 with other loadings based on the .221 Fireball case. Are these rounds related? What other variations are out there that I have to be on the look out for?

Thanks,
Paul


#2

Paul, how close are they to .300 “Whisper”?

Supposedly that is a 35.5mm case length…


#3

The 7.62x37mm was designed for HK’s SL9SD rifle. Picture the civilian SL8 with a shorter barrel and a sound suppressor.

I suspect the change in case dimensions was merely a way to avoid having to pay royalties to J.D. Jones (SSK) for use of the .300 Whisper.


#4

bsn - I’m not sure as I don’t have a .300 Whisper.

Daniel - thanks for the information. I googled the gun and found this picture.


#5

[quote=“Paul Smith”]I’m assuming that the ammo is of British manufacture and the weapon is by HK - i.e. a joint venture that has since come to pass.
[/quote]

FWIW: It was more than a joint venture. At the time, Royal Ordnance and HK were both owned by British Aerospace.


#6

[quote=“Paul Smith”]bsn - I’m not sure as I don’t have a .300 Whisper.

Daniel - thanks for the information. I googled the gun and found this picture.
[/quote]

en.wikipedia.org/wiki/.300_Whisper

I don’t know how accurate this is, but it might be a start.


#7

[quote=“Paul Smith”]bsn - I’m not sure as I don’t have a .300 Whisper.

Daniel - thanks for the information. I googled the gun and found this picture.
[/quote]

Paul,
I only know from an other sorce, that your 7,62x34 should be a forerunner of the later 7,62x37HK. This info comes from RSA, where the cartridge (which is in the ECRA Database) is situated. There you can also find the “owner” of it…
The Whisper is an other thing. The swiss RUAG also produced the Whisper for some special silenced guns in civil and military inventory.

The 7,62x37 cannot be made from a .221 FB, as this case is only 35mm long. The .300Whisper is in fact only a blown up version of the 221 FB, not changing anything else.
The HK by RG is based on this design, but could be made from anything, which had the same basediameter (.222/.223 aka 5,56x45). Whereas the last one is most possible, as this ammo or draw machines where at hand in Radway Green…

And an other thing: In the ammo fields/caliber"inventions": There is no royalty to pay at all, as a “cartridge” is already invented and not longer protected. This is only different, if there are special “new” inventions with the design/material or so…

Forensic


#8

Thanks, Peter. I appreciate the information.

Paul


#9

I’ve an article on my website on subsonic sniper rifle rounds. This is a pic from it:


#10

Tony,
the 9x39 shown in your picture is a “makeup” from a Czech collector, as the original ammo was not available, or not at an affordable price. It is NOT loaded and has NO AP-Core.
Just for Info

Forensic


#11

[quote=“Forensic”]Tony,
the 9x39 shown in your picture is a “makeup” from a Czech collector, as the original ammo was not available, or not at an affordable price. It is NOT loaded and has NO AP-Core.
Just for Info[/quote]
Yes, I knew that when I bought it (it was cheap!). I included it in the photo to show what one looked like, to compare with the others.

I believe that all genuine 9x39 ammo is steel cased.


#12

ok now we have the box