#SskIndustries

Previously, we compared the Russian 9x39mm subsonic sniper round to its Western counterparts, including the .300 AAC Blackout and the .45 ACP. As it stands now, the 9x39mm is a subsonic round only – no supersonic loads exist for it currently. But… What if they did?

Today’s Modern Intermediate Calibers will handle something a little different. While virtually all rounds we have looked at so far were designed primarily for supersonic use, today we will be taking a gander at the Russian 9x39mm round – a dedicated suppressed caliber designed exclusively for the subsonic flight regime, with no supersonic option (yet) available. This begets a question, then: Is the 9x39mm truly an intermediate caliber? To answer this, we should consider a few facts about the 9×39: First, it was designed for carbines and rifles with cartridge overall lengths comparable to common intermediate calibers, like 5.56mm or 7.62×39. Second, it was designed to give substantially better performance than is possible with pistol rounds, including armor piercing effect above that which is normally possible with handgun rounds. Third, it is used more like an intermediate caliber than a pistol caliber, being issued with a whole host of sniper rifles, assault rifles, and other weapons comparable to any other intermediate caliber. Therefore, I would argue that it is an intermediate, albeit possibly the strangest one in common use.

The .45-70 cartridge is created by SSK Industries. The company was founded and is run by famous cartridge designer J.D. Jones. Mr. Jones is the inventor of JDJ and Whisper families of cartridges. The .45-70 Whisper is made of .45-70 Government brass cut down to 1.6″ case length and loaded with long bullets fitting .45-70 Government’s overall length.

Previously, we talked about the Soviet 7.62x39mm caliber, which was paired with the famous Kalashnikov automatic rifle. With its much heavier bullet, larger caliber, and lower velocity, the 7.62x39mm contrasts heavily with the US 5.56mm caliber, and US weapons manufacturers took note. The .300 AAC Blackout is in many ways similar to the 7.62x39mm caliber, being – like the 6.8 SPC – inspired by it, but designed to add new capabilities. The origin of the Blackout lies in the earlier .300 Whisper, a wildcat developed by JD Jones from the .221 Remington Fireball to fire both heavy subsonic projectiles and lighter supersonic rounds with ballistic characteristics similar to the 7.62x39mm, while being highly compatible with existing AR-15 type rifles. Versus the older Whisper, the Blackout is little changed, but its introduction, backed by the force of Advanced Armament Corp, Remington, Barnes, and other companies, made it virtually an overnight success on the US civilian market.