Smoothbore Patched Round Ball Accuracy

[huntingsgr8]

This is my first post, so don't laugh too hard when I write something that doesn't make sense. I'm in the works of building myself a seriously kick@$$ muzzle loader, it's going to be a caplock 4 bore, that's right, a 4 bore. What stroke of insanity caused me to embark on something like this I'll never know, but one thing's for sure, my friends all agree I'm nuts. Not being able to efficiently rifle a barrel I've opted to make it smoothbore, which gives me the nice bonus of being able to load it with shot (my new favourite grouse gun?) sadly this also limits me to using patched round balls which I've read are only accurate for about 50 yards then accuracy gets bad. I was wondering if anyone has any experience using a smooth bore out to 50 yards and beyond and what sort of groups they got. I don't intend to use something this big at extended ranges, but I'd just like a ballpark idea of what to expect for accuracy.

[pworley1]

Have you ever seen a video of a knuckle ball in flight?

[waksupi]

I shoot them further than that quite a bit. Good accuracy can be had. Your limitation will be how much powder you can stand to stuff down that beast!

[Maven]

As Waksupi indicated, they can be surprisingly accurate out to 50 yd. and perhaps as far as 80. E.g., there's a 20ga. smoothbore shooter who regularly shoots in local ML matches and can hit 100 yd. targets regularly. (Keep in mind, those targets aren't minuscule.) The "secret" is in cheek weld, RB dia., patch fit, powder charge, whether an overpowder wad is used (felt is good), how good a shot you are, etc. Btw, you overcome the knuckle ball effect by pushing RB faster, but you've got your work cut out for you with a 4ga.

That's a .600" patched RB @ 25 yd. from my 20ga. trade gun replica.

[waksupi]

At the shoots around here, the smoothbore targets are the same as the rifle targets. Some go out to around 120 yards. I consistently shoot a better score with the smoothbore, than my rifle scores. Probably because I shoot my smoothies a LOT!

[huntingsgr8]

That's a pretty nice group, Maven. And yeah I know making a 4 bore, much less shooting one is no walk in the park, but hey I might as well go all the way if I'm going to make a big bore right? I also heard that it's the ball's decelleration from supersonic to subsonic that causes the accuracy issues. All other things being perfect does this actually have any effect?

[Maven]

Probably does, as the laws of physics don't care whether it's an aircraft decelerating or a sphere. However, I don't think it makes a significant difference over the distances we're likely to shoot. In the lab, well, that's a different story.

[thegatman]

cool idea let us know how it turns out

[bedbugbilly]

Maven sums it up very well. I have a 20 gauge (.62) flint Fusil de Chase and can get good accuracy most of the time out to 50 yards or so - after that, it's "iffy" but some of that is "me" and my "age".

A 4 Gauge? I owned an original 4 gauge "market gun" in percussion - sold it a few years ago when I downsized my collection. All I can say is . . . I hope you are a big individual and can stand a mule kicking your shoulder. :-) And . . . if you're going to shoot RB - hope you have a good supply of lead!

It will be an interesting project and I commend you on the undertaking . . . let us know how it goes and I'd love to see photos of it. What are you using for the barrel?

[fouronesix]

As to the sonic to subsonic transition of a lead sphere of that size having any issue with accuracy?? :) First you have to get to or beyond sonic velocity with that large ball and that will require a lot of BP. Additionally, about half of the BP used has to figure into the projectile weight as it will be ejected as solids during the firing. So, there is going to be so much recoil at that velocity, any sonic transition accuracy degradation would seem to be the least of the total accuracy equation which includes flinching and shooting technique.

As to the overall sonic transition vs accuracy theory?? I've rarely seen it but is does exist. It's common for some 22rf long rifle bullets out of a rifle barrel to reach sonic velocities at the muzzle but quickly drop below sonic between the muzzle and usually less than 50 yards. If the rifle and ammo are accurate otherwise, I've not noticed much if any accuracy degradation in the 22 bullet as it transitions. I have seen conical bullets go unstable at that sonic transition though. But those bullets were barely stable at the muzzle to begin with.

I just don't think you'll notice any accuracy difference with that massive of a sphere during the sonic transition in flight. Good luck getting to sonic velocity in the first place. And I think basic accuracy at any velocity or range will be the most challenge- if you're shoulder (and fillings) hold up long enough to do complete testing. But hey, sounds like fun and at least has some adventure in it.

[huntingsgr8]

Well an old published load for a four bore that I found was a 4 ounce round ball in front of 14 drams of powder and according to the book, it produced a velocity of a little over 1400fps. As for me being able to take the recoil well.....this isn't likely going to be the type of thing I shoot every day. Part of the beauty of making a monster like this is I'm at liberty to make it as heavy as I want, I'm hoping for about 20 pounds and according to the Weatherby recoil calculator it should produce about 175 ft lbs of recoil with the above load, and I'm no big guy, I'm 5'7" and 150lbs (after Christmas). For a barrel I plan on getting a piece of (what it's known as around here anyways) mechanical tubing. 1 inch ID, 1 3/4 OD, 30 inches long, that type of tubing is also heat treated, and I plan to be proof testing it with 50% more powder than what's in a max load and two 4 bore round balls. Calculating the density the barrel itself will weigh approximately 13 pounds, and I plan to compensate for that on the stock end heavily.

[fouronesix]

If it's relegated to shooting off the bench, then 20 lbs will certainly tame the recoil as you exceed 1000+ fps or so. But then a 4 smoothbore is not exactly a bench rest type target gun nor is it a field or hunting gun @ 20 lbs.... well maybe if hunting tigers from atop an elephant or shooting at pirates from a deck rail :) Still sounds interesting and adventuresome.

[waksupi]

Well an old published load for a four bore that I found was a 4 ounce round ball in front of 14 drams of powder and according to the book, it produced a velocity of a little over 1400fps. As for me being able to take the recoil well.....this isn't likely going to be the type of thing I shoot every day. Part of the beauty of making a monster like this is I'm at liberty to make it as heavy as I want, I'm hoping for about 20 pounds and according to the Weatherby recoil calculator it should produce about 175 ft lbs of recoil with the above load, and I'm no big guy, I'm 5'7" and 150lbs (after Christmas). For a barrel I plan on getting a piece of (what it's known as around here anyways) mechanical tubing. 1 inch ID, 1 3/4 OD, 30 inches long, that type of tubing is also heat treated, and I plan to be proof testing it with 50% more powder than what's in a max load and two 4 bore round balls. Calculating the density the barrel itself will weigh approximately 13 pounds, and I plan to compensate for that on the stock end heavily.


Playing with that type tubing is playing with fire. If you are going to do the project, get Rayl or some other custom maker to do the barrel. Shades of Cam!

[huntingsgr8]

waksupi. This type of tubing is drawn, perfectly seamless, and with walls 3/8 of an inch thick, and of heat treated steel (I'll make sure it's not heat treated to a brittle state) I think I'll be safe, but in any case that's what proof testing exists for, right?

[huntingsgr8]

And no, if and only if I ever use this thing for hunting, I'll be doing it from a blind or stand (tied down of course), it will most likely just serve as a sort of novelty, something I shoot once and a while when I feel nostalgic......and to entertain friends and frighten boyfriends if I have a daughter in the future.........just kidding on the last one.

[missionary5155]

Greetings
I remember reading an article about 4 bores being used in Africa. Story told of a big name hunter who generally used a 4 bore that weighed somewhere in the 15 pound area. When he touched off that beast it tended to drive him back a bit if his feet were not firmly planted. Seems the load was in the 8 dram area.
He also had a 2 bore that would spin him around like a weather vain.
Largest shoulder fired I shoot is a caliber .85. All my smoothbores will shoot minute of groundhog out to 50 yards if I can get a steady hold. They are all particular about ball-patch-charge and other little factors to get the best accuracy out farther which I seldom shoot as I hunt river bottoms, woods edges and drain ditches. My farthest shot to date on game is 33 yards.
Mike in Peru

[fouronesix]

The famous Frederick Selous, international hunter and conservationist whose name today has carried on as reflected in the huge Selous Game Reserve of Tanzania, used a 4 bore in Africa beginning in the 1870s. His recount of the 4 bore goes something like this:

“…the 4-bore guns kicked most frightfully and, in my case, the punishment received has effected my nerves to such an extent as to have materially influenced my shooting ever since, and I am heartily sorry I ever had anything to do with them.”

[huntingsgr8]

Yeah, but he depended on it, and shot it regularly. As I recall his was light by standards and he often loaded it with up to 20 drams of powder, I also recall reading about a double loading incident...

[Southron]

Does your state have a muzzleloading season for elephants?

[huntingsgr8]

No just a really bad squirrel problem:kidding:

[bhuch5]

No just a really bad squirrel problem:kidding:

http://ts1.mm.bing.net/th?&id=JN.GOmuU4oLyHeWxjasGaNDAw&w=300&h=300&c=0&pid=1.9&rs=0&p=0
Like this? Sorry for the hijack. Bruce H

[huntingsgr8]

Oh wow, that's hilarious:lol:.