5.56 Nato vs. 5.45 Russian

[HorseSoldier]

Will the AK-47 actually fire a 5.56 round? Yes , the extractor will hold the round in place enough , for the primer to be struck , but the case will expand after firing & get stuck in the AK-47.

As unattended soldiers firing both AKMs and Galils on the same range have discovered at least once, in my experience. Trouble shooting that was nicely complicated by removing the Galil mag before calling for help. Some headache and a cleaning rod later, problem solved . . .

 

[paintballdude902]

since most us troops were pulled out of vietnam in 72 i doubt they the nv army would have a rifle put into service 2 years later

i know the story very well my father a vietnam vet was the first to tell me it

i saw a pic of an sks(7.62x39) fire a 5.56 and it worked the casing split i believe or atleast was very bulged but it did work i dont know if it cycled the action but in a last ditch effort it would work

 

[sarduy]

Saiga .223

 

[RP88]

What I've always wondered is how do these compare ballistically and terminally?

you'll hear many different things from many different studies and 'experts' and opinionists.

the 5.56 vs. 5.45 vs. 7.62 arguments have a pro and con side for each. These arguments always end up going down one of the following roads: either "okay, but how does the Grendel or SPC rounds compare?", or "what happened to the good ol' days of the Garand and M14?"

Good luck on finding an answer.

 

[LaEscopeta]

I heard the design-your-own-rifle-to-fire-enemy-ammo story about the Japanese switch from 6.5mm to 7.7mm Arisaka rifle just before WW II. Supposedly the new rifles were designed for a 7.7x58 round that was slightly bigger than the US 30-06 and British .303 rounds, and could fire both US and British rounds. Quite a trick if it could actually be done, which it wasn’t.

 

[elmerfudd]

There are a handful of cartridges which will fire in firearms which are not chambered for them. A 7.62x51 NATO will fire if loaded into a 7.62x54R for example. It's generally not safe, yields minute of barn accuracy, and causes jams and parts breakage however. It's basically a matter of jamming a square peg into a round hole and then subjecting it to around 50,000 PSI.

As to shooting 5.56 through a 5.45 rifle, I'm extremely dubious about whether it could be done. Look at the pictures in Kurt D's post and you'll see just how much larger the 5.56 case is. How's that going to fit in a 5.45 chamber?

I have heard that 5.56 will chamber and fire in a 7.62x39 rifle however. It sounds much more plausible.

 

[-v-]

Here's a few observations of mine, date-wise they make sense. The Yugo's introduced the M67 round to remedy the poor wounding of the M43 round. The M67 had a large hollow space in the nose, similar to the 5.45 round, with the same design intention of tumbling upon impact. The M74 round was introduced 7 years later, and likewise shared the same construction characteristics. All commercially available 7.62x39 ammo now a days is built to the M67 standard.

Although they say that temporal cavity is irrelevant, I will also say at the same time, you can only stretch things so far before they rip. Plus, the 5.45 shot on brass-fetcher didn't produce impressive permanent cavity, but it did detach a piece of the ballistic Jell-o from the rest of the block, FWIW.

 

[Ivy Mike]

the 5.45x39 empty "brass " I've found at the range look like the 7.62x39 only difference is the neck is .22 cal and a different shoulder angle IIRC

The 7.62x39 and 5.45x39 are more dissimilar than that. About the only measurement they share is length and even that isn't exactly the same. The 5.45 case has noticeably less taper than the 7.62. Probably to reduce the curve in the magazines of the new rifles.

 

[SDC]

There IS at least one 22-calibre round based one the 7.62x39 round; the 5.6mm "Running Deer" cartridge used for simulated hunting competitions; maybe highlander found one of these, as unlikely as it may be.

 

[Z-Michigan]

To make life complicated, in the 1950's someone created the ".220 Russian" cartridge for hunting. It is a 7.62x39mm case necked down to .22. It is different from the later 5.45mm military roud, but there's plenty of room for confusion.

 

[PercyShelley]

The .220 Russian is also the basis for the PPC series of competition cartridges, as well as the 6.5 Grendel, which is why the Grendel shares its case head with the 7.62x39.