Norinco 24 Mil serial series

[Loose}{Cannon]

Welcome!

I'd be interested to hear the results of your hand loading. Although SKSs and AKs were never intended to be match shooters it would be interesting to see what they could do from very tight specification ammo, like Lapua or handloads.
.

Twas why I built me sks bench gun. 

[Greasemonkey]

Considering the enormous jump to lands on standard saami spec x39 chambers....  Getting closer to the lands with a heavier projectile would be a good thing.   

And wouldn't a longer bullet have a higher sectional density? Making it more aerodynamic? 

[Loose}{Cannon]

Why yes...  I think you are correct. 

[MxwllBkr]

Yes there is less section thickness, but there are no stress concentrations at the milled thread roots and no section transitions.  The section thickness is more than made up by the the heavy press fit into the receiver which provides excellent radial confinement around the chamber throughout the breech.  Threads by their nature can only be tightened axially with the cosine of the thread angle providing minimal radial confinement.

This right here is why I don't build guns or reload ammo............  that way I don't even have to try to figure out what you just said......

[running-man]

Laff Max, I don't reload either though I do have a full set of reloading supplies I got on the cheap from a guy who was moving out of town. 

I earn a living as a mechanical engineer.  Stress concentrations are absolute killers in my field.  The 'bullets' I deal with at work are measured in inches or feet with their weights in tens or hundreds of pounds and velocities anywhere from a leisurely 800 ft/sec all the way up to 4000. 

[Greasemonkey]

Yes there is less section thickness, but there are no stress concentrations at the milled thread roots and no section transitions.  The section thickness is more than made up by the the heavy press fit into the receiver which provides excellent radial confinement around the chamber throughout the breech.  Threads by their nature can only be tightened axially with the cosine of the thread angle providing minimal radial confinement.

This right here is why I don't build guns or reload ammo............  that way I don't even have to try to figure out what you just said......

I think it's mechanical engineer nerd speak... with his inverse cosine pressure stresses on the axially mounted radial confinement muffler bushing twice removed from his sisters side.... now to a mechanic who repairs and curses mechanical engineers, all I hear is the two are close enough in strength it just doesn't matter, pass the rosebud and hand me the 1 1/2 inch impact gun, I will break this bolt the f*** loose..

He is an expert in mineral oil too..    so I've heard. 

[running-man]

He is an expert in mineral oil too..    so I've heard. 

Laugh, no that would be Blicero.  I'm just a rifle licker.  That means I get to take a few ugly ones out of the safe sometimes, look them over, sigh, then put them right back in.  No range time for poor RM these days. 

[milboltnut]

really guys?

[Loose}{Cannon]

really guys?

Sure...  Why not?

https://www.google.com/amp/www.thefirearmblog.com/blog/2015/07/10/1moa-sks/amp/

[Phosphorus32]

really guys?

Sure...  Why not?

https://www.google.com/amp/www.thefirearmblog.com/blog/2015/07/10/1moa-sks/amp/

I knew of the rifle, of course, but how did I miss this article

[Loose}{Cannon]

Loose-Cannon from Texas had this SKS built

Fricking guy....  I didnt have it built..... I BUILT IT.  Welp, except for the barrel.   

[Loose}{Cannon]

food for thought?

http://castboolits.gunloads.com/showthread.php?140011-Very-Heavy-312-for-7-62x39

[Loose}{Cannon]

Maybe I go 200gr and subsonic the sucker.   

[Greasemonkey]

Maybe I go 200gr and subsonic the sucker.   

A US company back in the day.. Extreme Shock, sold a bunch of factory loaded 200gr x39 ammo. Midway and other venders sold it.. something like Subsonic Silent Warrior.

this fellow did sub and supersonic..
http://www.silencertalk.com/forum/viewtopic.php?t=64630



Seems some African nations/Germany/Finland used 174 grain x39 loads.............the STASI 
https://www.ar15.com/forums/ak-47/What_is_the_oddest_type_of_7_62x39_out_there_/54-151847/?page=1

There are some interesting AP rounds out of Finland that have a tungsten carbide alloy core and reportedly South Africa made something similar. I've seen some experimental sabot loads made in Belgium by FN. There are special loads called "helmet test" that use a heavy (200 gr. or so) at a prescribed velocity to test the armor properties of infantry helmets at the factory. I've seen these from Finland and East Germany. The East German helmet test was also reportedly used as a subsonic ball by the STASI.

One that I really like is the Soviet Type US subsonic ball cartridge. It is a normal appearing 7.62x39mm with a black over green tip. It has a 198 gr. lead core projectile with a hardened steel tip under the jacket.

The Rhodesians or South Africans made their own version of subsonic ball by remanufacturing 7.62x39mm captured from terrorists with a lighter powder charge. Another variation they manufactured used the 174 gr. ball projectile from the .303 British cartridge and a reduced powder charge. Reportedly only for use in milled receiver AK-47s not AKMs. Originally these had a blue tip. Usually when they turn up, the tip color is gone or mostly gone.

Russia had used a 12.55 gram bullet, known as the  7.62x39 is "US" (umenshennaya skorost)... a Spetsnaz/KGB wet work favorite..

I'll add that the projectile weight is about 192 grains. The projectile is very long and has a pointed, hardened steel penetrator about 10mm long in the front of the jacket, followed by lead. The powder charge fills about 1/3 of the case and is an extruded, stick type which is coarser than the powder used in regular ball ammunition. I do not have a pic of the round I sectioned, but it is an interesting load for sure. Most of these rounds are found in copper washed steel cases, but at least one load dated 1964 was in a lacquered steel case. According to my headstamp checklist, this load has been in production almost every year since 1961. A lot of the rounds with the 711 77 and 711 78 headstamps were captured in El Salvador or somewhere else in Central America in the late 1980's and early 1990's and found their way to collections here in the US.

https://forum.cartridgecollectors.org/t/silenced-7-62x39/218/3



Cool picture of Winchester brass x39 loaded heavy...  almost has this sexual aura to it...
http://olegvolk.net/gallery/technology/arms/ammo/762RS_subsonic_3092web.jpg.html?g2_imageViewsIndex=1




So... while you say it is unorthodox, unsafe, pressure spiking, wrong twist, inaccurate, blow the gas tube off the sucka, whatever...My end point is, heavy 170 grain plus x39 has been done for a long time, through out the Cold War till today. It's been done here in the US, by an ammo company and many a competent handloading guy, the Russian military and African militarys all have diddled with it.. I guess it boils down to, who really cares.. the new fangled 300BO/300 Whisper have superseded the need for x39 heavy ammo... they are running them in excess of 220grain in a smaller than the x39 case. 

Me.. there is way to much cheap surplus and commercial ammo in my basement to worry about dicking with it...but, oh how I miss Brown Bear battle packs for like 12.99..

[Loose}{Cannon]

Cannon likey.

[milboltnut]

Is there anyway the OP question can be the topic or will this type of behavior continue?

[Greasemonkey]

Is there anyway the OP question can be the topic or will this type of behavior continue?

The M43 Russian is a cartridge, a cartridge doesn't have a twist rate, a rifle does.. and most all SKS/Ak-47/Mosins are all between 9.45 and a 10:1 twist. As for "assuming" it is .311.. check it and verify. Reloaders do not assume.

As for will the behavior continue.... that is currently pending.

[Phosphorus32]

Is there anyway the OP question can be the topic or will this type of behavior continue?

The only question (in the form of a question) you posed was the groove diameter on your rifle and you answered it quite well yourself: .312.

The implicit question about twist rate has been answered: 9.45.

The assertion you raised later about 150gr bullets being the limit for 7.62x39 elicited additional interesting discussion and the presentation of information I hadn't seen before.

What else would you like to have addressed?

[milboltnut]

Load manuals limit bullet weight at 150....

heavier bullet decrease velocity... in any load manual I've used.

So basically yes, my questions were answered by running a over sized brush to find out twist of barrel. And I measured the grooves at the muzzle with a caliper, which by the way measures the same as slugging.

[Loose}{Cannon]

Is there anyway the OP question can be the topic or will this type of behavior continue?

All I see is a conversation on an interesting topic.