Cast bullet for 7.62x39

[harrygoat]

I am thinking about using a Magnus 32-20/115gr. hard cast bullet  in the 7.62x39R. Has anyone used this bullet or something very similar? If so what powder and charge  did you start out with?
 In short any info you could pass on would be very helpful.

                   Thanks HARRYGOAT

[Flash]

You may want to use a gas checked bullet if it's going to be in a gas operated weapon. Gas cutting(melting of lead on the bullet base) can fowl the gas ports in the barrel and cause poor cycling of the action. You'll need enough recoil to cycle the action too. I use a mild cast load with Lee's 160 RN but cycle the action by hand. I just caught your notation of the caliber. A 7.62x39 isn't rimmed, the 7.62x54 is. Was that what you meant? In a bolt gun, your bullet choice should be fine to work up a load with.

[jgalar]

I haven't had  any luck with any but spire point bullets in the SKS. Even loading single the round noses jamn. I just started casting the Lee 160 grain bullet, but have only tried un-gaschecked loads with 5 grains of Unique. They shoot well but they don't cycle the action. Do clean the gas system after shooting lead or it will gum up and you will have a hell of a time getting it clean. I use automatic transmission fluid to lubricate the gas system, it makes cleanup easy and I don't have fouling.

I have loaded up some gaschecked bullets using 2400. They should be powerful enough to cycle the action, but haven't tried them yet. Trying for an accurate load that just drops the empties at my feet. I hate searching for fired brass!

[Nobade]

I have been messing with something similar in my CZ 527  - Lyman #311008 over 5.0gr. Green Dot. It shot great, going into 1.5 MOA pretty consistantly. But the problem is the pressure is so low that the cases shorten, increasing headspace. After a couple of reloads they wouldn't fire anymore and had to be opened up, resized, and fireformed with full loads. The brass is very thin and shoulder easily set back. So when I want 32-20 loads I use my 32-20 and keep the 7.62X39 for full or nearly full loads. BTW, this is about the max velocity you'll want to run a plain base bullet - 1500 fps or so. Beyond that it's really tough to get any accuracy and most will lead the bore. For full loads use the Lee C-312-155-2R and book jacketed loads and you'll be happy. A full load of 1680 or 2200 works great in the SKS as long as the bore is cleaned of all jacket fouling first.

[harrygoat]

I failed to mention an important fact,I am working up this load for a single shot rifle, this I think would make a big difference. Sorry about my ommission.

                            Thanks HARRYGOAT

[jgalar]

Reprint from a C.E. Harris article:

Repeated reloading of rimless cases with very mild loads results
in the primer blast shoving the shoulder back, unless flash holes
are enlarged with a No.39 drill to 0.099" diameter. Cases which
are so modified must NEVER be used with full-power loads! ALWAYS
identify cases which are so modified by filing a deep groove
across the rim with a file and label them clearly to prevent
their inadvertent use.

[Leftoverdj]

OK, time to back up and start over.

Single shot means no worries about feeding, cycling the action, or clogging the gas system. Means much less worry about shoulder setback because the singleshot is not gonna have the SKS firing pin from hell.

What we do worry about is groove diameter. Cast bullets absolutely have to be a thou or two over groove size. That .32-20 bullet should be about right for most rifles, but there are extremes as tight as .308 and as loose as .314. If your rifle is the normal .310-.311, you should be ok.

Closest thing I have shot to your bullet is Lee's 113 grain GC and I think I used 18 grains of WC 680. My mould is from a group buy that specified they cast fat and an off-the-shelf mould may or may not cast the .311+ I need. The Lee C312-155-2R has shot so well for me that I have not put much effort into lighter bullets. Not likely to since I now have a 160 grain PB six holer mould that is taking care of my low velocity needs very nicely.

I'll give you some unorthodox advice. Any book load for the .32-20 and that cast  bullet will be safe in the 7.62x39 case but will give lower pressure and velocity. I'd compare the powders I have on hand to the book for .32-20 and pick a load that gave 200-300 fps more than I wanted in the 7.62x39. Avoid H 110 and WW 296 and you will be all right.

[harrygoat]

Thanks a lot Leftoverj. The info you provided was just what I needed. Youn have given me just the start I was looking for.

                   Thanks HARRYGOAT

[The Cast Bullet Kid]

Hi Harrygoat.
I have had some success in my SKS with a Lyman 311466 RN Loverin style mould that was opened up to throw .315 diameter bullets which I then size to .312.  
Check the twist in your rifle as most 7.62x39 barrels are WAY faster than they need be for the 123gr pills they get fed.  From memory the SKS carries a 1 in 9 1/4 twist which is faster than my .303 British  :shock: which explains why the SKS likes a 180gr RN Rem SP for shooting 100m target.  It only shoots at 1600fps on 23gr of W748 but makes nice groups and cycles the action just dandy.
All the best with the single shot rifle and if you search hard enough you will find literature that will give you data for stiffer loads than Mil. semi autos will handle but your rifle should.