I have two SKS rifles a 1970 Yugo M59/66A1 refurb and a 1965 Chinese /26\ I bought NIB several years ago. I shoot a little steel case ammo in them every now and then but the majority of my ammo is hand loads.
I hand load for everything I shoot that takes a primer and the SKS is no exception. I had full intention of doing so right from the start because in many cases the surplus or commercial ammo is neither consistent or accurate and the SKS is much more accurate than many people give them credit for provided you give it what it likes.
I load jacketed bullet from 123 to 187 gr. as well as cast bullet I cast myself from my Lee 160 gr. TL mold that drops a .313.5 dia. bullet cast from WW alloy. Both my rifles bores slugged out at .312 they both shoot the .310 dia. 123 gr. J bullet the most accurately but that's not to say that other weight's don't do well,in fact my 150 gr. SP and cast loads will out shoot any commercial or surplus ammo on the market,groups vary from one ragged hole to 1.5" or under provided I do my part.
My powders of choice are Alliant 2400 for cast loads and Reloader #7 for everything else,other powders like AA-1680,IMR or H-4198 and others all work fine as well but I get the best accuracy and bang for the buck with the powders I use as far as MV vs. charge weights. Reloader #7 works well with cast bullets also a starting load of 18.0 grs. will cycle any SKS rifle with the Lee cast bullet load that 2400 want. I use Lapua,Winchester and Remington brass,my primers of choice are CCI #34,Wolf LR and Wolf SRM. All load data for jacketed bullets in 123 gr. weights came for either the Lyman #47 or #48 manual both are the same. I used the load data from the Lee 2nd. Edition for 150 gr. jacketed bullets. Cast bullet date for the Lee .312 dia. bullets using Alliant 2400 came from Ed Harris but load data for those two bullets is available in the new Lyman Cast Bullet Manual #4.
My friend that has three Russian SKS rifles ran into that issue with shooting cast bullet using the Ed Harris 2400 load,one cycled fine,one about half the time and one not at all switching to the RL#7 solved that problem with no loss in accuracy in either rifle. Incidentally in my Chinese SKS my Chinese takes 12.5 grs to cycle the bolt reliably each time and it drops the brass right at my feet,MV is just a little over 1400 fps.with that load. My Yugo require the full charge of 15.0 grs. to cycle MV runs right around 1900 fps. but due to bolt speed the case end up about 15' away,my Chinese will do the same with the Max. load.
If loosing your reloadable brass is an issue there is somewhat of an easy fix to that but it requires a little time and and extra gas tube for your SKS I'll just link to the post instead of explaining it all but basically it amount to bleeding off excess gas pressure to slow down the bolt speed which affect only ejection pattern and distance,
http://castboolits.gunloads.com/showthread.php?t=116018 A couple of my friends have done the mod on spare gas tubes and no more chasing brass around. Again do this mod on a spare gas tube and not the original.
Some 5 shot 50 yd. groups with each rifle. The only modification to these rifles other than ammo was replacing the front sight post with the Techsight target post.
Some types of ammo I load.
52 gr. HP Accelerators
Lee 160 gr. gas check cast bullet.
