7.62x39 & Red Dot

[Deadeye]

I'm working on some loads for 7.62x39 using the Lee 160gr. bullet. I would like to use some Red Dot I have, but all the info I can find states no more than 5gr. That is not enough to cycle the action on my SKS. If it does not produce enough presure to cycle, what is the danger in increasing the load untill it does? I know theres a good reason, but I gotta know.
Thanks Deadeye

[grumpy one]

Someone who actually shoots that caliber will be able to help you out with details, but the basic issue here is that the cycling of your action depends on gas port pressure, and the gas port is out towards the end of the barrel. A fast powder, such as a pistol or shotgun powder, reaches its peak pressure pretty early in the bullet travel down the barrel and pressure has eased considerably by the time the bullet reaches the gas port. A slow-burning powder will reach peak pressure much later, and pressure will still be high when the bullet passes the gas port. So, since you are limited to what the bullet base can stand, and what the action itself can stand, if you use a very fast powder you'll run out of bullet strength and action strength before you get the action to cycle automatically. With a very slow powder, you'll get too much gas port pressure and pound your breech block back way too hard before you get enough bullet velocity. So in the end for self-loading actions you have to choose a powder within a fairly specific range of speeds. Manually operated actions can tolerate a much wider range.

[Buckshot]

.............I don't shoot it in an SKS, but a good load I've used before in a bolt action is 7.0grs of Red ot and the Lyman 311410. The slug is a 130gr RNPB. To add to what Grumpy mentioned, so far as fast powders go, in the 38 Special target load of 2.7grs of Bullseye, peak pressure is reached before the slug has cleared the cartridge mouth.

While Red Dot is slower then Bullseye, it is still rated fast for any application. My use of 7.0gr however showed NO signs of pressure anywhere, neither primer, report, leading (they were TL'd only), recoil, extraction, etc and etc. Your desired slug is heavier though. I'd start at their max of 5.0grs and then go up a half grain at a time.

I'd also load 5 rounds of each and for each range session I'd load only 2 grains higher in total tesitng. That way when the end becomes eveident you don't have a bunch to dis-load :-). It 'may' get you where you want to go. Be mindfull that the military loaded the 7.62x39 close to 50K pressures. To be sure, the actions will fully cycle well below that, but Red Dot just may be too fast to do it.

...............Buckshot

[Freightman]

I shoot a 150g C309150F LEE unsized in my AK with 19.5g of AA 1680 with no leading cycles the action fine.

[handyrandyrc]

I've used 6 grains of Red Dot in the SKS. I don't think you'll ever get it to cycle the action with that powder. No signs of overpressure for me. I've also tried in-between -- 5.5. Fun to shoot -- like a pop-gun.

[Jeffreytooker]

I've used 6 grains of Red Dot in the SKS. I don't think you'll ever get it to cycle the action with that powder. No signs of overpressure for me. I've also tried in-between -- 5.5. Fun to shoot -- like a pop-gun.


You might try your SKS as a pull bolt rifle. Shoot it with the plunger rod removed and manually cycle the rounds. Considering what they are (not a 70 Rem.) they shoot pretty well.

Jeffrey Tooker
Paynes Ck. Ca.

[vacek]

Maybe this will help

PRACTICAL DOPE ON THE 7.62x39

By C.E. Harris - UPDATED 3-27-94

I have reloaded thousands of rounds of 7.62X39 ammunition with
both cast bullets and jacketed, in the AK and the SKS. I got
frustrated with the AK as accuracy of these seems is generally
poor, at best about 5-6" at 100 yards. The SKS is more
reasonable, about 3-4" and is still a real bargain these days.
Most SKS rifles group better with cast bullets than they do with
ball ammunition. If you are new to cast bullet shooting or not
inclined to do a lot of experimenting, I recommend 14.5-15.5 grs.
of Hercules #2400 with the Lee .312-155-2R bullet, cast of wheel
weights and sized .312". With this load the rifle functions like
the proverbial pony trotting, and dumps the cases right at your
feet! You can also try 18-21 grs. of 4198 or 16-18 grs. of 4227
with any bullet from 122-125 grs.

The gas ports on these guns are larger than they need to be for
reliable functioning. Lead fouling of the gas port is not a
problem, but the gas piston and cylinder will foul, which can
affect functioning if neglected. The gas piston should be removed
and cleaned with Break Free, Marvel Mystery Oiil or Dexron IIe ATF
and 000 steel wool after each use, and the gas cylinder scrubbed
with a shotgun bore brush. Liberally lubricating with Break Free,
Marvel Mystery Oil or Dexron prior to reassembly eases the fouling
problem. You can fire several hundred rounds between cleanings
if you avoid super heating the rifle with rapid fire so that
the barrel becomes too hot to hold in the bare hand. If you do so,
and let the rifle cool without stripping and cleaning it immediatel
it WILL be difficult to disassemble!

I have not found lead fouling to be a problem in ordinary
National Match Course style firing, but only in factory endurance
tests of the Ruger Mini Thirty when I was at Ruger.

Ruger does not recommend handloads of any type. Therefore,
they don't recommend cast bullets at all. However, in my experience
cast loads about 1 grain heavier than the minimum which cycle an SKS
or AK will work in the Ruger. These pose no real functional
problem as long as the gas piston and its recess in the slide handle
are kept clean and well lubricated.

The only common cast bullet designs which are correct for the my
original NEI designs for this caliber and the Lee .312-155-2R
and TL.312-160-2R. The latter two are adaptations of my original
NEI design with minor changes to suit Lee's manufacturing process,
and to change the appearance slightly so the Lee version would have
a distinct "product identity." Now that NEI is back in business (51583
Columbia River Hwy., Scappoose, OR 97056) Walt Melander can provide my
original 52A design with its 1-1/2-degree tapered forepart or
a stepped-diameter design similar to Lee's adaption, but with a
blunter nose shape which is better for hunting. Accuracy-wise
there is no difference between them.

I designed these bullets with the intent to have the heaviest
bullet which could be loaded without the GC poking into the
powder space, and which would be big enough on the forepart to
fill the large throats on the AK and SKS, as well as in the
7.62x54R Russian, .303 British, 7.65 Argentine, 7.7 Jap, etc.

Use of a heavier bullet is also better suited for the typical
10-inch twist rates of 7.62x39 barrels. These bullets have only one
grease groove, (which is enough) and a substantial crimp groove .26"
from the base. The rear driving band casts .312", the front band
.310" and the forepart ahead of the crimp groove is .308." The ogival
radius starts from this point in order to maximize bearing length.

These bullets have proven very accurate in a variety of military
rifles for target work at up to 200 yards. They out shoots ball ammo
in the SKS or AK with any reasonable load. In a bolt- action target
rifle they are capable of 1-1/4" 10-shot groups at 100 yards, and in
a 2-groove 03A3 Springfield or M1917 Enfield they average around 2 moa
ten-shot groups at 200 yards with iron sights, with refined loads.

I use 1 part of linotype to five parts of wheel weight metal for
competition in my .30-'06 M1917 Enfield and M1903 Springfields up
to 200 yards with 16 grs. of #2400, 20 grs. of 4227, 13 grs. of
Red Dot or 12 grs. of 700-X. Accuracy of these light cast bullet
loads is far better than Ball M2 service ammunition. I use
the same charges in the .303 British and 7.62x54R Russian as
well. I fill the grease grooves with 50-50 Alox beeswax (Lee
brand) then tumble Lee Liquid Alox on for a light golden
overcoat. These loads don't lead for continuous use over the
National Match Course, even over double-strings of rapid-fire.

Above 1800 f.p.s. I use the same alloy, but cast the bullets
"hot" until they are uniformly frosted, then quench them directly
from the mould. The heat-treated, double-lubed bullets will
stand 2000 fps. in wheelweight alloy without leading, if shot
straight from the mould without sizing, being GC'ed in a .313"
die. A caseful (28 grs.) of Accurate 2230, 2460, or H335 gives
around 2000 f.p.s. in the 7.62x39.

Accurate Arms 1680 is very similar to the Olin 680 Ball powder,
though slightly slower. Both of these powders are used in
7.62x39 ball ammunition, with a charge of 24 grs. being correct
for service velocities with 123-gr. jacketed bullets using the
Accurate-IMI propellant, and 23 grs. for the slightly faster Olin
powder. For a full-power load approximating service ammunition
you can also use 26.5 grs. of RL-7 or 25.0 grs. of IMR or H4198.

With cast bullets the minimum load with 1680 which functions the
SKS with the Lee .312-155-2R is 16 grs. In the SKS this produces
about 1420 f.p.s. and 3" groups at 100 yds.; 18 grs. gives 1630
f.p.s. and 4" groups in the SKS. I did two strings with the Olin
680 for comparison with the NEI 155-gr. cast bullet at 18 and 19
grs., respectively, which gave 1810 and 1930 f.p.s. I would not
exceed 19 grs. of Olin 680, or 20 grs. of Accurate 1680 with the
155-gr. cast bullet, as these are both full loads.

The following tables provide additional test data on the 7.62x39.

Jacketed bullet handloads for 7.62x39- Lapua cases, Fed. 210
primers, Ctg. OAL 2.19" from CEH article in Handloader's Digest
12th. Edition, 1990, p.125.

20" P/V on Univ. Receiver. Vel. 24" Sako

123-gr. FMJ 24.5 H4198 2264 fps. 48,170 cup 2377
26.5 RL-7 2325 fps 52,000 cup 2451
28.0 H322 2180 fps 42,300 cup 2287
150-gr. SP 28.5 BLC2 2030 fps 40,000 cup 2140
23.0 RL-7 2050 fps 52,000 cup 2162

Accurate Arms 4th Edition for 7.62x39, SKS with 20.5" barrel
START MAXIMUM
123-gr. FMJ 24.0 A1680 2233 fps 26.5 A1680 2350 fps
26.5 A2230 1840 29.5 A2230 2086 fps

PS Ball for comparison, velocities from SKS with 20.5" barrel
Chicom 101-71 2415, 11 Sd
East German 04-77 2448, 11 Sd

[Lloyd Smale]

vacek thanks for your comprehensive post. Ive got a mini 30 and just ordered a ar15 in 762x39. My local hardware store had a bunch of wolf ammo and i bought 5 cases so id have something to shoot while recovering from the fire. When its gone ill have to try some of your loads. My mini never liked cast much but im hopeing the ar does.

[Lloyd Smale]

I guess i should be thanking robert. I see it was his post with the info.

[TAWILDCATT]

isn't the mini .308 barrel??my freind shot surplus and it was good,maybe the .312
lead might work even better.and with lead you might not be getting the pressure that a jacket would so 5 gr may be to low.try 6 grs and that my start to show action.I FIRED MY gARAND WITH 13 GR RED DOT AND 312-160 tl.it just opend the action a few inches.I did not expect it to function.just wanted to see what it would
do.it might work in the SKS with lower charge.I use the red dot 13 gr in all my military cases.
lead bullets dont have as much resistence and therfore should need more powder with less pressure.if this weather gets cool enuf I will be back at it.:coffee:

[bkbville]

Yikes -
I tried 7.5gr of Red Dot with the 312-160 (no gc) in my Siaga.

I sighted in with wolf first and shot this load... I couldn't even get this on paper. I shot 10rds and eventually located 3 holes on the backboard - 18" or so lower than the target - very verticle torn looking holes (was it tumbling?)

...scary when you know where it's going.

I'm going to try it with gc's and maybe Unique instead.

[Daryl]

You might try your SKS as a pull bolt rifle. Shoot it with the plunger rod removed and manually cycle the rounds. Considering what they are (not a 70 Rem.) they shoot pretty well.

Jeffrey Tooker
Paynes Ck. Ca.

Jeffrey,

You mentioned to remove the plunger rod. I'm new to the SKS and have enjoyed it very much. I have read about the reduce loads by CE Harris and will be doing so. To do so and manually cycle the action, does the plunger rod need to be removed?

Thanks

[machinisttx]

isn't the mini .308 barrel??my freind shot surplus and it was good,maybe the .312
lead might work even better.and with lead you might not be getting the pressure that a jacket would so 5 gr may be to low.try 6 grs and that my start to show action.I FIRED MY gARAND WITH 13 GR RED DOT AND 312-160 tl.it just opend the action a few inches.I did not expect it to function.just wanted to see what it would
do.it might work in the SKS with lower charge.I use the red dot 13 gr in all my military cases.
lead bullets dont have as much resistence and therfore should need more powder with less pressure.if this weather gets cool enuf I will be back at it.:coffee:

Ruger 7.62x39 barrels are .308.

[machinisttx]

Jeffrey,

You mentioned to remove the plunger rod. I'm new to the SKS and have enjoyed it very much. I have read about the reduce loads by CE Harris and will be doing so. To do so and manually cycle the action, does the plunger rod need to be removed?

Thanks

Removing the gas piston will prevent the rifle from cycling even if a load with enough pressure is used. You will have, more or less, a straight pull bolt action. Just be sure the bolt is fully forward and locked before firing. The disconnector in the trigger mechanism should keep the hammer from falling if the bolt isn't fully locked. I haven't looked at the design of the bolt enough to know if the hammer is prevented from contacting the firing pin if it falls before the bolt is fully locked...some other rifles are designed that way as an additional safety feature.

[RU shooter]

I havent loaded for the SKS with cast but have in my AK , With the lighter boolits 160 and lower I had marginal success with with the faster powders(unique and faster) a simple fix was just moving to a heavier boolit like the Lee 185 and shot well and functioned with lighter loads that I didnt think that would. And on an even heavier note a 220 gr plain based 311290 at 1300 fps does wonders on the 100 yd steel reactive targets !


Tim