What Happened?
 

Hi everyone,

I was target shooting with my .54 cal Blunderbuss, and I was noticing that the shot spread REALLY fast. I was using 80 grains Pyrodex Select, 1 over powder wad, 80 volume grains of #6 shot, and 1 over shot wad. I was shooting groups at least 36" in diameter at 12 yards.

This got me thinking. I said to myself, "Is there any way to get this shot group tighter? Its a Blunderbuss, so probably not."

I proceeded to experiment. I had a weird idea, and I am still not sure where it came from. The idea was to use a 4:3 ratio of powder to shot, and to double the over powder wad.

I then tried 80 grains BLACK POWDER (I ran out of Pyrodex,) 2 over shot wads stacked on top of each other, 60 volume grains of #6 shot, and 1 over shot wad.

At the same distance, 12 yards, I shot a 19" group with this. In fact, all but 12 pellets hit the 17" target.

I have one question. What happened? How did my shot group tighten? Only a few things changed. The type of powder changed, but I disproved this was the reason after trying 1 over powder wad with it and getting some 36" groups. The thickness of the over powder wad changed by me doubling it with 2 wads. The amount of shot changed by my odd idea of the 4:3 ratio of powder to shot.

So, what happened? How did it tighten?

I would upload pictures, but there is a persistent error happening.

Jared

It's called finding the right load.
What I've always been told on my side by side front end stuffers. Equal volume of shot to powder.
So I started with 50/50 and adjusted there to either 60/40 powder to shot ( which at times can blow holes in patterns) to 45/55.
And it all changes with wad thickness and/or the use of a shot cup.
Once you find consistent load and I mean every load don't fiddle with it.
And then add a 2nd barrel sitting right next door. And you start all over again as with all my side by sides.

Ive spent hours/days developing loads for what I own. In 2020 shot turkeys with all 3. Even flat out missed too.
Head scratcher on that one.

JW

Sounds like you found a load that works.

Keep tinkering with it and see if it can improve. Keep good notes so you can go back and see what was best.

Both above good advice. You may even want to consider using a plastic shot wad/cup to tighten up the pattern even more.
One reason that your pattern may have been tighter with 2 wads (and I'm assuming here) is that the extra wad cushioned the shot pellets. Deformed pellets can fly off in all directions. That's where a modern shot cup would help out.
I'm just thinking out loud. I never owned a BP shotgun but I have reloaded shotgun shells.

Thank you all for getting back. I appreciate it.

I don’t think I can do shot cups, because the barrel is .54 cal. Unusual size for a shotgun. Then again, this is a blunderbuss, not a shotgun.

I plan on using this load in a spring turkey hunt, starting on April 15. I’m going up to North Idaho for this hunt.

For the time being, and until after the hunt is done, I will stick with this load I came up with.

Then, I will start experimenting and see if I can get it tighter.

I kinda doubt I can get it tighter, though. Like I said, this is a blunderbuss.

That reminds me, I figured out how to aim with a blunderbuss. There’s no sight on it, so you have to use the top of the bell as the sight.

Thanks again, Jared

Did you shoot beyond 12 yards?

Good luck on your hunt. That would be an awesome one if you can get it done!

No, I didn’t. You got me curious now, so I will do that tomorrow. I’m pretty sure that 12 yards is the maximum effective range. According to my math calculations, the shot spreads about 1 foot every 6 yards. At about 18 yards, the spread might be 3 feet with this load. I’m not certain, though. I will try tomorrow.

Have you tried larger shot?

Yes, I have, actually. I used buckshot a few times, and got groups as big as my hand at the same distance.

What is the largest shot you may use for turkey in your state? Might want to try that, those guns were not meant for fine shot in their day.