7.62x39 which powder for cast

Swampman · Aug 2, 2022

CoalCrackerAl said:
Oh the 2400 data came from an old Hodgkin manual. #26 I find it to have a lot of data not found in newer books. It has all powders in it.

I'm unfamiliar with the manual you referenced, but back when Alliant listed pressure tested data for 2400 in 7.62x39 they showed a "Never Exceed" charge of 14.8 grains with a 150 grain Sierra soft point.

I'm not saying 16 grains is necessarily going to be dangerous (your C.O.A.L. IS two tenths of an inch longer), but it would probably be a good idea to work up to it by shooting a few at lower charge weights.

Screenshot_20220802-010233_Adobe Acrobat.jpg

I love 2400 for mid level cast loads, but if you want to push jacketed bullets at higher velocities, there are much better powders out there.

Bfh_auto · Aug 2, 2022

Swampman said:
I'm unfamiliar with the manual you referenced, but back when Alliant listed pressure tested data for 2400 in 7.62x39 they showed a "Never Exceed" charge of 14.8 grains with a 150 grain Sierra soft point.

I'm not saying 16 grains is necessarily going to be dangerous (your C.O.A.L. IS two tenths of an inch longer), but it would probably be a good idea to work up to it by shooting a few at lower charge weights.

View attachment 1093647

I love 2400 for mid level cast loads, but if you want to push jacketed bullets at higher velocities, there are much better powders out there.

I think his data is from before the Hercules/Alliant switch.

Swampman · Aug 2, 2022

Bfh_auto said:
I think his data is from before the Hercules/Alliant switch.

You're probably correct.

It's also likely to be from before SAAMI dropped the maximum pressure of 7.62x39 from 50,000 CUP to 45,000 CUP/PSI.

Personally, if I'm loading jacketed for hunting, I use the CIP spec of 3550 Bar (@ 51,500 PSI). But I always do a work-up from well below max.

CoalCrackerAl · Aug 2, 2022

Yes it's before the switch.

Swampman · Aug 2, 2022

I couldn't find the original post by C. E. Harris, but here's a link to a re-post of his excellent "Practical dope on the 7.62x39".

It's got a lot of great info.

I think the article predates powder coating, but in my opinion, that's not nearly as important for a single shot or bolt action as it is for a gas gun.

Bfh_auto · Aug 2, 2022

Swampman said:
I couldn't find the original post by C. E. Harris, but here's a link to a re-post of his excellent "Practical dope on the 7.62x39".

It's got a lot of great info.

I think the article predates powder coating, but in my opinion, that's not nearly as important for a single shot or bolt action as it is for a gas gun.

I read that. But thank you for adding it to the list.
16 grains of 4198 was an epic fail. I'm going to bump the charge weight and see what happens. But I'm not holding my breath on this combo.

AJC1 · Aug 2, 2022

Bfh_auto said:
I read that. But thank you for adding it to the list.
16 grains of 4198 was an epic fail. I'm going to bump the charge weight and see what happens. But I'm not holding my breath on this combo.

Epic fail as in squib or just throwing them in the dirt. I expected you to find satisfactory loads in the 18-19 grain area.

Bfh_auto · Aug 2, 2022

AJC1 said:
Epic fail as in squib or just throwing them in the dirt. I expected you to find satisfactory loads in the 18-19 grain area.

6" groups at 50 yards. No squibs. I started at 16 because it was the minimum and I'm 5 grains heavier.

AJC1 · Aug 2, 2022

Bfh_auto said:
6" groups at 50 yards. No squibs. I started at 16 because it was the minimum and I'm 5 grains heavier.

At minimum load their probably not stable. Work a single shot pressure ladder up to 18 and test 18-19

Bfh_auto · Aug 2, 2022

AJC1 said:
At minimum load their probably not stable. Work a single shot pressure ladder up to 18 and test 18-19

I'm going to try 18 grs. 16 was far too low.

AJC1 · Aug 2, 2022

I don't know how hard your lead is. You will most likely find a sweet spot below max where it stabilizes but doesn't shotgun. It seems to do that on both ends for me.

Bfh_auto · Aug 2, 2022

AJC1 said:
I don't know how hard your lead is. You will most likely find a sweet spot below max where it stabilizes but doesn't shotgun. It seems to do that on both ends for me.

These are coated 18bhn. My mold is coming in soon. I'll be running softer lead when it does.

Bfh_auto · Aug 4, 2022

I am ordering another mold because my barrel slugs at .312.
They will be the .312-185 and .312-150.
I have SKS, mosin, 30-30, and 30-40. So I should be covered with the 170 fn and these two molds.
I have .309, .311, and. 314 sizers.

7.62x39 which powder for cast

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