Australian 7.62

[LIMPINGJ]

I have acquired 5 cases of this ammo and it’s ok in my M1A and Remington 700 but not great accuracy. I am considering pulling some down and working up a cast boolit load. Any idea of what powder the Australians used in their 7.62x51 ammo and has anyone worked up loads with it?
Thanks

[ShooterAZ]

I have some too, it's pretty accurate in my guns. I pulled some down once, and the powder closely resembled Varget. It's probably some type of canister powder though, I would never assume it actually was Varget. I didn't work up any cast loads with it. Also, of the 5 cases that I got 4 were Berdan primed, and one was boxer primed.

[MostlyLeverGuns]

For a place start - breakdown 10 or a dozen - weigh the powder charge, weigh the bullet, fire another 5-10 over a chronograph, check loading manuals for powders that come close to the velocity with that bullet weight and charge, that will give a place to start. Careful load development after that.

[P Flados]

For a place start - breakdown 10 or a dozen - weigh the powder charge, weigh the bullet, fire another 5-10 over a chronograph, check loading manuals for powders that come close to the velocity with that bullet weight and charge, that will give a place to start. Careful load development after that.

The concept above can work pretty good if you have a good feel for working with a mystery powder.

You can also examine the powder and compare it to known products. Australian ammo is likely to use ADI powder. ADI also makes Hodgdon stick powder and some are "the same" with different names. A complication to this effort is that certain powders may have been made in an original "long" form but later was also made in a "short cut" form.

https://www.ilrc.ucf.edu/powders/sample_detail.php?powder_id=73

Measure the density (measure the weight of powder to fill a case in grains, then measure the weight of water in grams to fill the same case). Since 1 gram of water is one CC, dividing the powder grains by the water grams gets a result of grains/CC. Comparing this to known powders can also be useful.

https://leeprecision.com/files/instruct/VMD.pdf

So if you find a powder that has nearly the same burn rate (estimated based on grains to get similar velocity), same appearance and same density, you have a "similar reference" powder.

[Wilderness]

The older berdan primed stuff (NATO mark in HS) was loaded with 2201, and the later boxer with 2206, both about 3031 speed. Can't swear on the changeover coinciding exactly with the primer change. Current stuff MAY be 2206H (H4895), since it replaced 2206 commercially.

[Winger Ed.]

I'd break some down, weigh the bullets & powder, cases, and look for variances.

After that segregate some cases & bullets, and brass that are exactly the same weights.
Then ease off the powder a grain or two at first, and put them back together to see how they do.
If it goes well, and they're accurate, I'd be happy.
I'd use the Berdan cases at places where they'd go off into the grass, or I wouldn't bother to collect and save the brass.

Going forward, I'd probably get some Match Kings and/or Game Kings the same weight
to use with more of the pulled down cases & powder.

[Rapier]

NATO ammo is loaded to a standard pressure level so it can be fired in any NATO Country's guns, all need be done is just find a commercial powder accuracy load for a 308 within the pressure limits, toss the old powder. Use good accurate .308 bullets.
Seems like the Australians served in the desert, if the ammo was shipped to Saudi or Iraq it could have gotten fried in the heat. The Australian SAS was here in the US at Special Operations bases, at times.

[barnetmill]

NATO ammo is loaded to a standard pressure level so it can be fired in any NATO Country's guns, all need be done is just find a commercial powder accuracy load for a 308 within the pressure limits, toss the old powder. Use good accurate .308 bullets.
Seems like the Australians served in the desert, if the ammo was shipped to Saudi or Iraq it could have gotten fried in the heat. The Australian SAS was here in the US at Special Operations bases, at times.

When powder goes bad from heat, it releases corrosive nitrogenous break products that can attack the copper in the brass case making it brittle. If it happens it would be manifested by a lot of green corrosion or at least that was my experience with such ammo. The nitrates in smokeless powder are the result of nitrating with nitric acid and other chemicals like sulfuric acid are essential to the process.

[fc60]

Greetings,

Something not mentioned is the bullet diameter. A lot of NATO spec ammo use 0.307" bullets.

Check your Australian bullet diameter.

Cheers,

Dave

[Stephen Cohen]

I think your accuracy problem is due to barrel twist, We used that ammo in our Omark mod 44 target rifles which had rather slow barrel twists. My Omark has a 1 in 14'' twist and so is the second barrel I have for it, I believe they were made in 1 in 12'' 1 in 13'' also. I believe I know the powder used but if you supply the year of manufacture on the base it will make it easier. My Omark with this ammo shoots inside 1/2''but I will not shoot the remaining few I have in my collection. I have also heard that Australian 7.62 was at one point loaded to to a higher pressure which was reduced as it was deemed too hot for the M14, I can not swear to the validity of this though. I wish I had 3 cases of this ammo. Regards Stephen