Making a smokeless 8-bore cartridge

[matt85]

I was sitting around bored today and decided it might be fun to make a small tutorial of how I make cartridges for my 8-bore 3.25" double rifle. Use at your own risk!

1. I start with a primed 3.25" case and 67gr of Alliant Blue Dot.

2. Next is four 1/2" cushion wads, three overshot cards, and one 1/8" nitro card. This stack-up is simply what I found got the bullet to sit properly at the top of the case and has not been tweaked for accuracy reasons. These are pressed over the powder using tools included in the 8-bore load kit from RMC. A simple dowel would work as well but getting the thick cushion wads started can be a little difficult.

3. For the projectile I typically use the 84-1200 mold from Accurate Molds. Mine was customized to produce a 0.850" bullet. I also have a push through sizing die that was custom made for me by a gentleman off another forum. The alloy I'm currently using (random scrap lead) is producing 0.849" bullets weighing it at 1240gr.

4. For seating the bullet, I simply put a little Duco Cement around the forward driving band and push the bullets in by hand. I haven't tested this glue extensively, but the idea is to prevent the bullet from shifting under recoil instead of crimping. I got the idea from a black powder cartridge forum and have been testing it in recent loads. Here is the final result:

Lastly here is a picture of the assorted components used in the making of this cartridge:

 

[Sarg]

Fantastic thank you for posting that info, I only load black in my 8Ga shotguns so far as wads are a real hassle to get in NZ.

Been going to build a 8bore rifle on a shotgun action for over 10yrs have barrels & kiln gun cases (what I use in my shotguns as well) & RB mould I was going to use Nitro in this as it will be a bit lighter & the Nitro has a bit less recoil, even less with the 850gr or so RB load .

 

[matt85]

Fantastic thank you for posting that info, I only load black in my 8Ga shotguns so far as wads are a real hassle to get in NZ.

Been going to build a 8bore rifle on a shotgun action for over 10yrs have barrels & kiln gun cases (what I use in my shotguns as well) & RB mould I was going to use Nitro in this as it will be a bit lighter & the Nitro has a bit less recoil, even less with the 850gr or so RB load .

a ball over smokeless powder produces pretty mild recoil. I have tried the same 67gr Blue Dot load under a 0.853" ball with some success. But the terminal performance of an 8-bore ball load isn't great. So, I haven't put much effort in creating a good load.

 

[Sarg]

Do you really think a .835 cal Ball is not terminally effective ?

I’m sure I don’t know as I haven’t shot any big game with the 8bore but a lot with the 12bore double rifle I have, it is a 3in magnum type of about .745 calibre using 7 to 8 drams of BP, unfortunately I have only shot medium size animals & never found a bullet/ball but have read of a much lesser 12bore shooting balls through Elephants heads, ok it was 150yrs ago & the slightly smaller Indian elephants but shit that's pretty good ?

I’m only going to be playing with this anyway & don’t think I’ll chase Buffalo let alone an Elephant with it but I would like to know ?

 

[matt85]

I do not believe the 8-bore round ball is suitable for elephant. Perhaps it might be fine for other dangerous game. But I can't imagine why I would pick a ball over a conical. The conical would be much more effective at odd angles and be less likely to deflect off large bones.

 

[VertigoBE]

Thanks for sharing this @matt85 was very interesting to read about all that goes on reloading with smokeless.

As I have zero reloading experience, I’m surprised by the amount of wadding you have to put in. This is due to smokeless being much less volumetric than black powder for the same energy I suppose?

 

[matt85]

Thanks for sharing this @matt85 was very interesting to read about all that goes on reloading with smokeless.

As I have zero reloading experience, I’m surprised by the amount of wadding you have to put in. This is due to smokeless being much less volumetric than black powder for the same energy I suppose?

It takes considerably more black powder to achieve the same results. Per the ledger, the original load for this gun was 10 drams or 273 grains of black powder. If memory serves, I was using something like 265gr of Schuetzen FFg black powder to get decent regulation.

Developing a nitro-for-black load is dangerous though. I did not fully develop this load on my own. I started with load data from the late Cal Pappas. Thanks to him, I had a good idea where to start when working on my own load.

 

[deewayne2003]

Thank you for posting this, it's been a while since something interesting to read was posted!