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?
hi and welcome. good to have you here. thumb1 I just buy factory ammo (what's ever on sale), so don't have an answer (sorry). pullhair1
thanks Carls... thumb1
Welcome.. thumb1
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.
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
I've always used 00buck pellets for slugging a .30 cal bore.
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.
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.
Quote from: Greasemonkey on November 20, 2017, 05:18:42 PM
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? think1
150 is the limit for bullet weight guys...
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
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?
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.
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.
Quote from: Greasemonkey on November 21, 2017, 02:21:36 AM
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. thumb1
Quote from: milboltnut on November 21, 2017, 07:43:40 AM
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 think1 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.
QuoteIf 9.45 twist wont stabilize a heavy bullet think1 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.
Quote.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
Quote from: milboltnut on November 21, 2017, 12:05:29 PM
Quote.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. thumb1
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. thankyou1
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. thumb1
Quote from: Phosphorus32 on November 20, 2017, 02:33:39 PM
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.
Quote from: Loose}{Cannon on November 21, 2017, 03:01:51 PM
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. thumb1
And wouldn't a longer bullet have a higher sectional density? Making it more aerodynamic?
Why yes... I think you are correct.
Quote from: running-man on November 21, 2017, 09:51:28 AM
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...... chuckles1
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. thumb1
Quote from: MxwllBkr on November 21, 2017, 06:46:18 PM
Quote from: running-man on November 21, 2017, 09:51:28 AM
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...... chuckles1
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.. chuckles1
He is an expert in mineral oil too.. thumb1 so I've heard. :)
Quote from: Greasemonkey on November 21, 2017, 11:29:19 PM
He is an expert in mineral oil too.. thumb1 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. chuckles1
really guys?
Quote from: milboltnut on November 22, 2017, 11:33:24 AM
really guys?
Sure... Why not?
https://www.google.com/amp/www.thefirearmblog.com/blog/2015/07/10/1moa-sks/amp/
Quote from: Loose}{Cannon on November 22, 2017, 01:32:08 PM
Quote from: milboltnut on November 22, 2017, 11:33:24 AM
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 thumb1
QuoteLoose-Cannon from Texas had this SKS built
Fricking guy.... I didnt have it built..... I BUILT IT. Welp, except for the barrel. :-X
food for thought?
http://castboolits.gunloads.com/showthread.php?140011-Very-Heavy-312-for-7-62x39
(http://www.fototime.com/B00712C607BC255/standard.jpg)
Maybe I go 200gr and subsonic the sucker. :P
Quote from: Loose}{Cannon on November 23, 2017, 12:06:04 AM
Maybe I go 200gr and subsonic the sucker. :P
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.. thumb1 thumb1
http://www.silencertalk.com/forum/viewtopic.php?t=64630
(http://i39.photobucket.com/albums/e198/ToxicSports/splitcase.jpg)
Seems some African nations/Germany/Finland used 174 grain x39 loads.............the STASI :o
https://www.ar15.com/forums/ak-47/What_is_the_oddest_type_of_7_62x39_out_there_/54-151847/?page=1
QuoteThere 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..
QuoteI'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
(http://img291.imageshack.us/img291/1336/762m43reducedmg8.jpg)
Cool picture of Winchester brass x39 loaded heavy... almost has this sexual aura to it... thumb1
http://olegvolk.net/gallery/technology/arms/ammo/762RS_subsonic_3092web.jpg.html?g2_imageViewsIndex=1
(http://olegvolk.net/gallery/d/38939-1/762RS_subsonic_3092web.jpg)
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.. rofl2
Cannon likey.
Is there anyway the OP question can be the topic or will this type of behavior continue?
Quote from: milboltnut on November 23, 2017, 06:24:21 PM
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. thumb1
Quote from: milboltnut on November 23, 2017, 06:24:21 PM
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?
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.
Quote from: milboltnut on November 23, 2017, 06:24:21 PM
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. dntknw1