Possible reasons & fixes for flyers

[roundball]

Green Mountain .54cal Flint Smoothbore barrel for a TC Hawken, 15/16" x 33".

70grns Goex 3F
OxYoke wonderwad
.015" lubed cotton patch
Hornady .530 balls

Excellent PRB accuracy with 70grns Goex 3F...from a ragged hole to cloverleafs at 50yds.


PROBLEM WHEN TRYING LARGER POWDER CHARGES:

80 and 90grns Goex FFFg (3F) also produce good groups, EXCEPT there's always a predictable flyer in every 5 shot group;

80 and 100grns Goex FFg (2F) also produces good groups, EXCEPT, there's a flyer in each group;

Using orange 3" aim point stickers in the middle of a white paper plate, 4 shots will cluster on the sticker, but one flyer will be out on the edge of the paper plate at 9:00 o'clock one time, then maybe 5:00 o'clock during the next group, etc...no pattern.

Let's assume I've got it together enough at this point to accept my word that all else is equal like range conditions, shooters repeatability, and components/cleaning/wiping/lubing/loading, etc, etc.


After hunting season is over I want to experiment to see if I can fingure out how to get it to tolerate a larger poowder charge...the only thing I can think of right now is this, and I'd like your opinions.

Is this a possible cause/fix:

Using one Oxyoke wad over the powder like I'm doing, is it possible the larger charges and their pressures are occasionally forcing past the edge of a wad just at muzzle exit time, tilting the wad like a tilted conical, causing some blowout at that point effecting the ball which is just airbore at this point...causing a flyer?

And if so, I wonder if using two wads would eliminate this edge blowout effect on the ball by giving a better seal...or using the next caliber size (.58cal) wad in it so it's tighter?

Or any other tips you might have from first hand experience that might cause these occasional flyers with larger powder charges?

 

[pathfinderifh]

If you have the accuracy you want, why would you want to burn more powder than you have to? The stuff isn't cheap anymore,[I remember $1.78 a lb!] and the added increase in velocity and energy isn't enough to risk a flyer in a critical situation, like beating a rifled gun! :blah:

Pathfinder

 

[roundball]

"...If you have the accuracy you want, why would you want to burn more powder than you have to?..."

To get more energy at longer ranges.

"...The stuff isn't cheap anymore,[I remember $1.78 a lb!]..."

The difference of another 10-20 grains of powder in an occasional hunting load would not make enough difference in cost to measure.

"...and the added increase in velocity and energy isn't enough to risk a flyer in a critical situation..."

Correct...which is the actual point of my post...looking for folks with hands on experience in determining the cause(s) of flyers when certain power levels are reached.
:v

 

[AZ-Robert]

Roundball, what kind of groups do you get if you skip the over-powder wad?

If uneven venting at the muzzle as the wad slips out one edge first is the cause, maybe going for uniform venting by using only the patch is a fix?

I note in Bob Spencer's noteboook, he uses the overpowder card in addition to a wad.
[url] http://members.aye.net/~bspen/SmoothboreLoads.html[/url]

 

[roundball]

Roundball, what kind of groups do you get if you skip the over-powder wad?

If uneven venting at the muzzle as the wad slips out one edge first is the cause, maybe going for uniform venting by using only the patch is a fix?

I note in Bob Spencer's noteboook, he uses the overpowder card in addition to a wad.
[url] http://members.aye.net/~bspen/SmoothboreLoads.html[/url]

Interesting...never even tried it with just the patch by itself...have used a wad with hunting loads for so many years I never thought about not using one.

I'll add that tip to the "Try This" list...
:hatsoff:

 

Just don't shoot the predictable flyer! :rotf:
Sorry Roundball, I couldn't help myself. Seriously though try an overpowder card with and without the wad. I have even used the heavier over the shot card with good results. Bill

 

[Wes/Tex]

I've found through the years that smooth bores take some tinkering with the loads. For some reason I've never figured out, it usually requires trying balls patched and unpatched, cards and wads below and with and without an overshot card, etc. It gets a bit overwhelming but the results can be very revealing. One liked unpatched balls with an overshot card...go figure!

 

[roundball]

Just don't shoot the predictable flyer! :rotf:

:rotf:

 

[Grenadier1758]

Just how often do you wipe the bore? I find that I get a build up of fouling at the breech that can prevent me from setting the ball at the same spot. Does your predictable flyer always occur at the same shot of your five shot group? Is it the first shot or your last shot? The problem with wiping the bore between shots is that you can build up fouling in the touch hole area and that could be a cause of flyers.

 

[roundball]

When I run these kinds of range tests, every shot is as precisely engineered and duplicated as I can possibly do it...right down to aligning the threads in the patches the same way every time, and I test from a clean cold barrel each shot.

The discipline of taking identical process steps each and every shot shows up in the extremely tight group with 70grns of powder...the only thing that has changed when flyers begin to appear is the larger powder charge.

No pattern to the flyers, either in target location or order of occurance...once or twice I had two flyers in a five shot group, but usually only one out of five, and not necessarily a flyer in every group.

In fact when I first tried my proven .54cal hunting load of 90grns Goex 3F that I use in rifled bores, I had only shot a couple of quick three shot groups at 50yds, they all stayed on a 3" aimpoint sticker, and I mistakenly assumed I was good to go with the same hunting load. Only later when I began firing five shot groups did I discover there was a flyer occuring every now and then.

I'm convinced that this smoothbore barrel should be physically capable of firing good groups with larger powder charges...I'm just intrigued with the challenge of finding out what it's going to take to do that.

 

[smoothshooter]

Check your tang screw to see if it is tight first. Loose tang screws are famous for causing double grouping (two separate groups close together using one point of aim) and uncalled fliers. Not resting or holding the forend at the same place or the same way can affect the way the gun recoils and cause strays. I don't think wads tipping at the muzzle coming out is the problem, because the wad is going to totally cup/form around the rear half of the ball as soon as the powder starts to burn and before the ball even begins to move. Someone else has suggested more wad stack experimentation, and that is something else I would try, such as putting an overshot wad under the cushion wad. It MIGHT even improve the gas seal, but there will always be some leakage, even with a patched ball; maybe just making this leakage more consistant will help.-smoothshooter-