The wonderful, baffling world of smoothbores

[Snow on the Roof]

I worked up a fairly heavy load in my Garner built .20 ga, for what turned out to be an ill fated elk hunt. The load consisted of 80 gr Goex FFF an oxyoke felt wad followed by a cast .600 an .010 ticking patch. This load gave me 4" groups at 25 and 5.5" at 50 yards. The biggest issue was an unpredictable flyer. No reason or pattern to it just out of the blue a wild shot out of the group.
New day, back home in Illinois I was just playing around with the fowler. Since I was low on .600's, and not in the mood to cast some more,I pulled out a jar of .575 cast RB's and used some .020 pillow ticking. To add to the mix I decided to use up an old can of Goex FF and reduced to charge from 2-1/4 drams from the usual 3 drams.
The results? after 30 rounds all the shots where in a 3-1/2" group with all shots varing from 15 to 50 yards and all shots either offhand or sitting {no bench used}. Curiously the point of impact raised apx an inch and the best part was no flyers! Every shot went predictably into the same 3+ inch hole no matter the range or position.
This certainly has me re-evaluing my loads for this gun but can anyone explain to me why the improved accuracy and why the raise in POI? The undersized ball withthe heavier patch seemed to work very well. One obsevation, FF is much dirtier but if I get such improved accuracy using it I won't mind the extra 15 minutes of clean up time.

Snow

 

[Many Klatch]

It could have been the felt wad messing you up. I know of very few smoothbore shooters that find a use for wads when shooting roundball. The one shooter that I know that uses a wad and a roundball only uses it in an original 1816 musket with a bad spot in the barrel.

I normally use 3F in my .60 smoothbores and 2F in my Bess, but your gun will tell you what works and what doesn't.

Many Klatch

 

[BrownBear]

No clue on the smaller groups, but I'm wondering if the raise in POI is due to lower velocity, i.e., more "dwell time" in the bore between ignition and exit from the muzzle, so the ball is exiting at a higher point in the recoil cycle. I sure see the same thing in handguns, with faster exits resulting in lower hits and slower exits striking higher. Speculation for sure.

 

[Mike Brooks]

I have never found powder loads as large as 80gr to work well in 20 bores.
Garner probably uses pipe for barrels as most Corinth school gunbuilders are apt to do, this may have something to do with your large groups too. I still don't think you have found your load, 3" is still pretty big. Also with these Corinth school guns you better check how well your breech is bedded against the wood and make sure your barrel lug slots have been elongated.

 

[hanshi]

I've got a similar .62 from Matt Avance and it's a fine gun to be sure. I normally use 3F and have been working with .590" ball cast from WW. While so far performance has been adequate I saw some possibility after trying a few shots with 2F. Accuracy is more consistent with 1/2" op cushion wads or at least a felt wad or two and using .020" patches. The load thumb starts. With .600" ball and 010" patching I collected a deer but it was at close range. I find little difference - though there seems to be some - in the fouling left by 3F and 2F. Like you I don't mind a tiny bit more fouling if I get good accuracy.

 

[Stumpkiller]

I've been playing in a similar situation at a slightly larger bore. I have 200+ cast balls of 0.648" to 0.651" (old Dixie cast balls) in a 16 bore: nominally 0.662" I can't get a patch around them with the 5/16" hickory rammer to force them down. I started at 75 grains of FFg and it was dismal (or I was with a new gun). 60 gr was better and a hair over 65 gr FFg (the measure averages 67 gr weighed for 10 samples) was 2-1/2" three shot groups at 30 yards consistantly. So it appears there is a "sweet spot". I'm still playing. Also playing with shot patterns.

Ain't it great!

 

[Snow on the Roof]

I have never found powder loads as large as 80gr to work well in 20 bores.
Garner probably uses pipe for barrels as most Corinth school gunbuilders are apt to do, this may have something to do with your large groups too. I still don't think you have found your load, 3" is still pretty big. Also with these Corinth school guns you better check how well your breech is bedded against the wood and make sure your barrel lug slots have been elongated.

Mike I am certain this is a tube barrel but it is my first smoothy and a learning experience. I believe a conversation between us, to improve my gun battery, is in the future. I really, really like that 16 gauge you built for Stumpy. As to the thee inch groups, that is fairly good considering my eyes and poor shooting habits but as I said, I'm learning.

I used the felt wad with the 80 gr load to prevent patch burn. An .010 patch was as thick as I could use with a .600 RB. Perhaps with a .590 RB .015 ticking would work, I don't know. Thats just one thing to try then again that is what I love about this stuff, I keep learning while getting to burn powder. How KOOL is that??

Snow

 

[Britsmoothy]

My little musketoon improved when I noticed with my finger nail the muzzle was slightly rough and I smoothed it out.

My current load is a .562 ball and .018" linen in the .577-8 bore. So tight I have to use a short starter.

Being lazy I had got in the bad habit of tapping the ball in the muzzle with the ball of the short starter. A few shots later and it soon became apparent it did not like it one bit!

Funny critters.

Brits.

 

[roundball]

A few years ago I discovered that the fairly soft Oxyoke felt/wool wads were causing me flyers with PRBs out of .54cal and .62cal smoothbores.
Conclusion was gas pressure bends them up around the bottom curve of the ball somewhat and occasionally there is one side that allows a slight 'blow-out' right at muzzle exit, barely nudging the ball off course.

Stopped using them and stopped having flyers. Started using them again and started having flyers again.
So I eliminated wads and changed my PRB combos to:
.540 bore = 90grns Goex 3F, .520" ball and .022" patch;
.620 bore = 110grns Goex 2F, .600" ball and .022" patch;

The faster I push them the more accurate they are at the range I zero them because they don't get a chance to slow down and let the knuckle ball effect creep in.
Outstanding accuracy, each averaging 2.5" groups at 50yds, seated hunting position leaning against a post (like it was a tree).
I fully expect my deer loads would easily cloverleaf if I shot from a solid bench rest.

 

[Shine]

Corinth school ,good one. :rotf:

 

[roundball]

Here's the smoothbore built by Matt Avance / TVM that I was referring to:

Rice D-weight swamped .62cal smoothbore barrel
Chamber Deluxe Siler
Davis Double set triggers

 

[hanshi]

Matt makes fine custom guns and yours certainly fit in that category. Those stock are beautiful, rb.

 

[flintlockmdj]

I don't see any blood on the deer in the picture!
How long did it take to train him to lay that still?

 

[Marc Adamchek]

Every time I see one of your "new" guns, Sir Roundball, a pang of envy doth creepeth in my noggin.

And they SHOOT!

 

[roundball]

Top quality Flintlock for sure and at a very reasonable price.

That morning I had only been in the ladder stand 10-15 minutes after 1st light when I heard something coming through the leaves over my right shoulder...this guy passed by just 15-20yds away angling up and away to my left in front of me, with his head down on a hot Doe track like a bloodhound.

Watching him moving slowly away it occurred to me that when he got a little further out in front the angle would be just right to try and slip a ball in behind his left rear most rib and it would go forward through his heart, possibly even on forward into the neck vertebrae as his head was down like that.
I managed to make the shot at 35yds and he dropped in his tracks with that big ball all the way through and on into his neck.