7.62x39mm reloading help


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mookiie
April 7, 2013, 09:15 PM
I am loading 7.62x39mm with IMR 4198 and am almost te max recommended load by Hornady or Lyman. Still seems under powered compared to a Russian surplus round. My question s - is their a better powder to use for 7.62x39mm? Can anyone who loads for it give me some tips? I am shooting them in a Yugo SKS.

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Matt Dillon
April 7, 2013, 09:43 PM
How do you know they are under powered? Do you use a Chronograph? I use Reloder #7 for 7.62x39.

FROGO207
April 7, 2013, 09:51 PM
Well first off what size and weight bullet are you using? Most SKS's like to use 123 grain .311 jacketed bullets best. For best VEL use Accurate 1680. IIRC that was the propellant that was designed for it. With the 28.3 grain max charge your VEL should be around 2445 FPS. I have been using X-Treme plated RNFP 123 grain plated bullets using 20.2 grains of IMR 4198/OAL 2.076 with good results in my SKS. They are accurate and do not eject the brass into low earth orbit after smashing them on the way out either. Are your rounds accurate? If so then the extra oomph that the surplus rounds use to make sure of ejection is not really that necessary IMHO. You could also try X-Terminator or Reloader-7 for a good propellant match.

Tolkachi Robotnik
April 7, 2013, 10:15 PM
Steel cases have a different pressure limit. There are a lot of 7.62X54R loads in steel cases from Russia that I would not dare to break down and put inside brass cases of any kind. They would not even approach a safe load.

The steel cases are a one shot thing. Your reloads probably will not over top the speeds you can get with some steel case Russian loads. You most likely will be able to get some load that shoots better for group sizes out of your own loads.

If you had a chronograph you might be surprised by what some of the 'factory' or surplus loads are doing for speed.

If you want something a lot faster and stouter than 7.62X39 there are lots of options. Realize you are in a 30-30 arena, there will be diminishing returns and much peril to make your shooting iron into a Ackley Improved Short Magnum of some sort or another. I would encourage restraint.

Marlin 45 carbine
April 7, 2013, 10:56 PM
don't see the OP mentioning that.

1680 is a good powder. flashey though.

mookiie
April 8, 2013, 09:15 PM
No cronograph, the action does not always clear the ejected case. Not an issue with the gun have used it before without issue. That is what made me assume the handload is the issue as it was my first time using handloads vs surplus/brown bear. the surplus was yugo brass cased and the brown bear were steel cased. I am reloading brass cases boxer primed.

bullet is a 123 grn .311 dia spire point.

I do have a crono but had not used it with this load yet.

I am not implying that I want something that shoots faster or is heavier than the 7.62x39mm round. I was wondering if maybe others have experience with IMR 4198 loads or something they found preformed better.

It may not be the ammo, I just wanted to bring a second load in something that may preform slightly better than the IMR if I could.

Marlin 45 carbine
April 8, 2013, 09:35 PM
WW680 or AA1680 are good powders for the .39.
yes I have used 4198 - shot great groups loading w/Lee loading gear however did'nt cycle 100%, more like 75%.
have you tryed 322 under a 150gr slug? good combo in my Mini30

steve4102
April 8, 2013, 09:37 PM
It's your powder, not the amount of powder. Your IMR 4198 is not producing enough "port" pressure to cycle the action. Port pressure is the amount of gas/pressure that travels down the bore and enters the gas port cycling the action. Port pressure should not be confused with chamber pressure and adding more powder will most certainly increase chamber pressure but may not increase port pressure enough to cycle the action.

My Ruger Mini-30 struggled with IMR 4198 as well. Switch powders and you should be GTG. AA 1680 is always a great place to start as it was designed for the X39.

mookiie
April 8, 2013, 09:45 PM
It's your powder, not the amount of powder. Your IMR 4198 is not producing enough "port" pressure to cycle the action. Port pressure is the amount of gas/pressure that travels down the bore and enters the gas port cycling the action. Port pressure should not be confused with chamber pressure and adding more powder will most certainly increase chamber pressure but may not increase port pressure enough to cycle the action.

My Ruger Mini-30 struggled with IMR 4198 as well. Switch powders and you should be GTG. AA 1680 is always a great place to start as it was designed for the X39.
Thanks this is what I was looking for!

wetpowder
April 9, 2013, 12:14 AM
Thank you Steve, I was wanting to try reloading that cal too

joneb
April 9, 2013, 12:43 AM
I have had good results with IMR 4198 and H-4198 with Hornady 123gr sp and fmj in a Russian SKS with LRP.
H-4198 at the middle of the load data per Hornady manual provides very good accuracy and function.
Have you cleaned the the gas port ?

Cherokee
April 9, 2013, 08:49 PM
1680 works great in my AR x39 but the most accurate load is with H335.

thagunman
April 10, 2013, 01:45 AM
i prefer 4227 imr 18 gr under 150gr. 308. cycles my aks great. i load both russian steel, yugo brass and boxer brass

thagunman
April 10, 2013, 01:46 AM
i believe the cartridge is more like a magnum pistol round rather then a rifle round. so a faster powder may give you some better cycling results

targetback
April 10, 2013, 01:56 AM
I use RL7 no problem, I use a lee dipper I'm not sure the number of hand I do not have my book right here, but it fills the case to just in the neck ,that I like also. But check it out before loading. Target

steve4102
April 10, 2013, 08:50 AM
i believe the cartridge is more like a magnum pistol round rather then a rifle round. so a faster powder may give you some better cycling results

Actually just the opposite is true, faster powders produce less port pressure/gas than slower powders. Reducing the gases needed to cycle the action can cause worse cycling results, not better.

Think 30-06 Garand, powder to fast and the action does not cycle, not enough gas. Powder to slow the action and gun will be damaged, to much gas.

mookiie
May 25, 2013, 11:48 PM
Finally got back to the range and the AA1680 worked like a charm and cycles great! Thanks for the help guys!

Sent from my DROID BIONIC using Tapatalk 2

Ken70
May 26, 2013, 01:43 AM
1680 was formulated for AK's, didn't have any other use than 22 hornet. Then the 300 Blackout appeared. 1680 is the go to powder for 300 Blackout, so of course, you can't find it....I found a pound last halloween, just before the "blackout". They don't make much of that.

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