Reloading 7.62x39 bullets and powder into .303 brit

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rm_rang

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I have done this successfully before with 7.62x54r by decreasing the charge by a percentage (30% I think) and working up from there till my primers weren’t popping out.

I am now wanting to do the same with my now un needed 7.62x39 rounds (as I sold my sks)

I imagine it’s possible by increasing the load by a percentage to avoid a flashover (not sure what that is but I read if the case isn’t full enough it will cause a flashover) I got an average weight from 10 rounds (I will confirm weight once I get home) for both the powder and bullet.

Does anybody know if this is possible or am I completely out to lunch?

Thanks!
 
I have done it lots with Czech x39. I think from 26ish grains I made it up to 36 grains before I had a stable load I was happy with. A simple swap will produce massive velocity spreads, mine were as high as 400fps. I am guessing "flashover" is supposed to be another name for secondary explosive effect, which outside some very rare circumstances is a myth and/or a common excuse for reloading screw-ups.
 
Its a real fast powder. Just use all the powder from the x39 in the 303 case with the 123gr bullet. Ive made for then 500 over the last few years

You can up the powder charge and watch for pressure and watch velocity i wouldnt push it to hard. But no risk with only using the 26gr is comes with

H110 and real slow rilfe powders you have to worry about reducing too far. Most powders dont care if its loaded low. Do reading on a cast bullet forum or cast bullet manual


Load of cast bullet data with less then 30% case full no fillers either

Hell even hodgdon lists a load of 8gr of titegroup in 308 win with 160gr jacket bullet

You can read what the x39 powder is close to then use that data.

Or you can find out your self. Weigh a charge from your x39 case also check velocity, using the charge weight and speed, also know its close to max load, go through manuals and find what powder has near the same charge weight and velocity near max... you then will know what you are working with
 
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Yes, you can load 1 for 1.

or you can load a bit hotter.


If I was doing it, I would try 25 to 30 gr, in one grain increments to see if there was any accuracy node.

The bullet is hardly match grade, so if you don't find any big improvement, just load 1 for 1 and call it a day.
 
I've not heard of flashover------
I think he's describing detonation.
I also load 1 for 1. '39 bullet and powder charge in 303.
It's a plinking load fo me, 50 yds and under.
 
I tried d4198 as a reduced load for .303. The ballistics were hardly worth it. I'd be tempted to try it in a .223/5.56 , or if you dont have that caliber trade or sell it.
 
I prefer to pull down x54r, but no reason x39 wouldn't work. Some have reported erratic velocities, others had no issues with a straight 1 to 1 load (other than lower velocities from the 303 load compared to the original x39 due to the lower pressure caused by the bigger chamber in the 303)
 
Hi

Around 10 years ago I was in the similar situation, one 3/4 full case of 7.62x39 ammo and no more SKS and yes I did reload on 303

I simply pull ou bullet and powder from 7.62x39 and load it onto primed 303 case.... work correctly but not exceptionnaly accurate, just a cheap plinker hitting 8" or 10" gong a 100 yards..

The only drawback was that overall lenght was way shorter than normal ammo so often the round to be loaded was "jumping" out the mag too quickly and jam against the side of the receiver/barrel so the bolt had to be slowly pushed in order to avoid pushing the bullet in the case.

Also by the end of the 7.62x39 case I read an article on upside down bullet for (subsonic or accuracy I dont recall), so I decide to try some. Their loaded shape ressemble 303 blanks and they cycle considerably better, almost no jams. Their accuracy was a little raised but since I was at the end of the case I ran out of ammo before serious test were done. Their velocity also seem to be little higher too

I can't tell if it was safe but after firing over 700 round in total I never encounter pressure signs of other trouble except for jamming explained above

Larry
 
I done up 300 rounds - 762 into 303
The gun was accurate.
Nice easy recoil.
different sound out of the barrel.more of a "crack"

However- watch out for HANG FIRES !
you are putting a smaller amount of powder in.
I had 3 hang fires. Its a real surprise !!
so I shot the rest off,....but carefully.
I wouldnt do it again because of this.
 
lone ranger said:
I done up 300 rounds - 762 into 303
The gun was accurate.
Nice easy recoil.
different sound out of the barrel.more of a "crack"

However- watch out for HANG FIRES !
you are putting a smaller amount of powder in.
I had 3 hang fires. Its a real surprise !!
so I shot the rest off,....but carefully.
I wouldnt do it again because of this.
Click to expand...

Go to your local fabric store and buy a square meter of one cm thick Dacron fiber or something similar. It's used to line foam pillows on couch seats, etc, before the outer cover is put on.

It only costs a few dollars.

Cut it into one cm squares and stuff a square over the powder column in the case, then seat your bullets. This holds the powder back against the flash hole and prevents hang fires. I use this with 308Win, 30-06 and 303Brit for light loads.

NO, it doesn't increase pressures
 
I have done a few of both. Can't say I've had any problems. The 54R way is probably going to produce a bit more accuracy. I used 75% of the powder from 54R. The x39 way is a lot simpler. Fun to try anyway. I urge .303 shooters who don't cast their own to buy up all the x54R they can afford, as it will dry up, like the 8x57, 30-06, 8x56R etc., has done.
 
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