Norinco 24 Mil serial series

[milboltnut]

Hi guys,
            new here... searched the web and found this site. Took awhile.

Like to load for this rifle to see what kind of accuracy I can get. I guess not that good. I found data in my lyman manual for the twist rate i have 9.45. My hornady manual lists 7.5 twist for the M43 Russian.

I also noticed the groove dia. can vary due to the extra expander ball that comes with the die set. I assume the groove in the model I have is .311 or so?

[carls sks]

hi and welcome. good to have you here.    I just buy factory ammo (what's ever on sale), so don't have an answer (sorry). 

[milboltnut]

thanks Carls...

[Greasemonkey]

Welcome..

The number I've seen quoted for years, says the twist rate is 9.45, you can check and verify with a tight fitting patch and cleaning rod. Count the number of times the rod turns in relation to the length it travels. Typically the SKS share the .310/.311 bore with the Ak-47, .303 Brit, Mosin, and 7.7 Japanese.

The different expander ball may be for a .308 dia bullet, which you could find early Ruger Mini 30s had a 7.62x39 chamber, but a regular .308 bore. If your that gungho on accuracy, slugging the bore would be the only way to truly find exactly which size bullet would work best. This method is commonly used on Mosins or Enfields and reloading for accuracy, due to the slight variance in Finnish Mosin bore sizes, some can be tight like a .308, others might take the regular .310 bullet, and some really worn Russian/Enfield bores can exceed .312. Directions for bore slugging can be found pretty easy.

[milboltnut]

forgot about other rifles chambered for 7.62x39.... that explains the extra expander ball.

I checked the twist as you said... it's right there.. 9.45.

As far as slugging.. I've done it but using the right slug, not a fishing weight, commercial ones, would be best. Thanks for your input.

Measures .312

[MxwllBkr]

I've always used 00buck  pellets for slugging a .30 cal bore.

[Phosphorus32]

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.  I have had 3" groups and nearly had sub-2" groups (if it wasn't for a "flyer"  ) from cheap commercial steel case ammo in my Romanian at 100 yds.

Nearly all of the military or commercially manufactured ammunition for 7.62x39 rifles is 122-125gr, except for the 154gr soft points from Tulammo. All of the bullets are advertised as .310 or more rarely .311 diameter, again in the 123gr range except for a Barnes MPG lead-free frangible bullet at 108 gr. Reloading options are rather limited in regard to bullet choice.

[Greasemonkey]

Often wondered how .32acp or .32 H&R Mag bullets would work in light loads.. They are .312 which I wouldn't think would cause a huge pressure issue. I have seen someone, Berrys or Hornady has a 100gr/110gr .311 bullet. And I have seen some load the .303 Brit 174gr bullet in the x39 case....must be a heck of drop on that.

[Phosphorus32]

Often wondered how .32acp or .32 H&R Mag bullets would work in light loads.. They are .312 which I wouldn't think would cause a huge pressure issue. I have seen someone, Berrys or Hornady has a 100gr/110gr .311 bullet. And I have seen some load the .303 Brit 174gr bullet in the x39 case....must be a heck of drop on that.

I've wondered the same thing about .32 cal bullets. I wouldn't be too concerned about the thousandth of an inch.

However, loading that long 174gr bullet would cause me some concern, or at least questions I'd want answered first. Would you have to load it deep to avoid having 0.000" to the leade? If so, what does that deep loading do to the initial pressure inside the case? Perhaps not much if you have to decrease your powder load for decreased case capacity. Would you need a slightly slower deflagration rate on your powder? 

[milboltnut]

150 is the limit for bullet weight guys...

[Greasemonkey]

Like I said.. people have done the 174gr in x39. 

https://hillpeoplegear.com/Forum/forumid/24/postid/10282/scope/posts

http://www.accuratereloading.com/76239.html

[milboltnut]

it was loaded in a mauser and  kreiger barreled rem 700... which is a stronger barrel/rifle..

But in a sks.. especially a pinned barreled action I would not do, would you?

[Greasemonkey]

Been done subsonic in an Ak.

http://www.theakforum.net/forums/19-ammunition-reloading/187563-7-62x39-subsonic.html

http://www.thefirearmblog.com/blog/2016/06/25/exploring-untapped-potential-7-62x39-around-hunting-caliber/


I was only trying to say x39 has been loaded with a bullet weight higher than 150gr.

As for my opinion on pinned vs threaded SKS versions, to me thats like the hex vs. round Mosin receiver. No one has definitively, scientifically proven or tested either to absolute failure and then duplicated the test to verify, and then had the results verified by someone else to prove that one is x times stronger, or was weaker than the other.

Remember, there are unknown millions of automatic AKs that are probably 50 plus years old in the Middle East/Africa/Europe with pinned barrels, that have been abused and hammered full auto for years, and are still hammering to this day.

[milboltnut]

pressure is the key factor.... and heavier bullets create it. Besides that 1:9.45 twist isn't fast enough to stabilize heavier bullets for this cartridge.

[running-man]

As for my opinion on pinned vs threaded SKS versions, to me thats like the hex vs. round Mosin receiver. No one has definitively, scientifically proven or tested either to absolute failure and then duplicated the test to verify, and then had the results verified by someone else to prove that one is x times stronger, or was weaker than the other.

Remember, there are unknown millions of automatic AKs that are probably 50 plus years old in the Middle East/Africa/Europe with pinned barrels, that have been abused and hammered full auto for years, and are still hammering to this day.

I would tend to think pinned is as strong if not a stronger design than a threaded lug.  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.

Of course, by 'stronger', does that mean a factor of safety of 5 vs 4?  Hard to quantitatively say, but it's pretty clear the Russians and Chinese both overdesigned in many areas on both versions of our favorite carbines. 

[Greasemonkey]

pressure is the key factor.... and heavier bullets create it. Besides that 1:9.45 twist isn't fast enough to stabilize heavier bullets.

If 9.45 twist wont stabilize a heavy bullet   Then how did Finland and Russia get away with Mosins that were between 10:1 and 9.45:1 and still shoot 174 grain heavy ball so accurately. I have several Mosins that love heavy ammo, and they shoot it very well. The K98 and most 8mm Mausers are 9.45:1 and it was using 196 grain bullets, and stabilized them.

What about pressures in a 148-154gr light ball x54r, 172-184gr heavy ball x54r and 203 gr Silver and Brown Bear ammo, all are still both below the maximum allowed pressures. Does 147gr 9mm generate that much more pressure than 115 gr 9mm, 220gr 10mm develop that much more pressure than 135gr 10mm, 220gr 30-06 develop that much more pressure than 150gr .30-06?  Maybe a little more pressure, but they are still all below the maximum pressure and safe for the respective weapons. If they weren't, you would see a ton of High Points, Glocks and various hunting rifle blown to bits, have a ton of law suits.

Sure pressure can cause issues.. but you have a maximum pressure loading that most, if any will exceed due to safety. Start low and work your way up, check and verify. Plus, some....alot of common sense comes into play, one is just not going to shove a Buffalo Bore .45/70 500 grain load in an 1873 Springfield Trapdoor...Ok...maybe someone would do it, but only if they wanna roll the dice and dont enjoy living, thats a case of stupid fixing itself.

[milboltnut]

If 9.45 twist wont stabilize a heavy bullet   Then how did Finland and Russia get away with Mosins that were between 10:1 and 9.45:1 and still shoot 174 grain heavy ball so accurately. I have several Mosins that love heavy ammo, and they shoot it very well. The K98 and most 8mm Mausers are 9.45:1 and it was using 196 grain bullets, and stabilized them.

Different calibers... dictate different specs.

.Ok...maybe someone would do it, but only if they wanna roll the dice and dont enjoy living, thats a case of stupid fixing itself.

That pretty much says it all...doesn't sound like you're on the band wagon.. does it?

Pressure spikes cause inaccuracy, BTW

[Greasemonkey]

.Ok...maybe someone would do it, but only if they wanna roll the dice and dont enjoy living, thats a case of stupid fixing itself.

That pretty much says it all...doesn't sound like you're on the band wagon.. does it?

Pressure spikes cause inaccuracy, BTW

If I did reload x39.. I would try it. But.. thats just me.   I take the SKS for what it is, a historical, minute of man rifle. I do have some that could possibly do better accuracy wise, but I have other rifles far better in accuracy I can doodle with.

And like I said before.. heavier bullets have been tried and used, didn't say you had too. 

[milboltnut]

from what I read... loading heavier bullets provided no real improvement with the x39....

saying that... 30-30 comparison is liken unto the .243 Winchester and the 6mm Remington.. apples to apples. I like macintosh and my wife like red Delicious. 

[Loose}{Cannon]

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.