How to pattern a cylinder bore shotgun?

[Widows Son]

Hello all, I hope everyone is well.

There is so much wonderful information on this forum that it can be hard to wade through. Pardon me if this is an already answered question.

I’ve got a 12g Pedersoli sxs made in 1985, both barrels are cylinder bored. I just shoot clays using #7.5 and #8 chilled lead shot.
I’d like to know how different loads (powder charge/wads/shot) can change the spread or point of aim? It seems that at 25 meters it shoots a little low and right. My usual load is square (1oz powder, felt wad, 1oz shot and overshot card).

I know there is no substitute for actual range time and experimentation. However black powder is rather expensive and hard to get at the moment so I’d like to have some ideas of where to start rather than hoping I’ll get lucky.

Regards
Joe

 

[LawrenceA]

There is an old rhyme that pretty well sums it up.

Little powder, lotsa lead, shoots far kills dead.
Lotsa powder, little lead, kicks hard wide spread.

Start with a square load by volume (so same volume of powder as shot). You can go to about 30% more shot than powder I am told.
Also look for the "Skychief" load on this form.
Pedersoli and TOTW will give loading data.
Should get you started

 

[LawrenceA]

It seems that at 25 meters it shoots a little low and right.

If it was a double rifle I would say the load in that barrel is too fast. But it is a shotgun.
When you say a little are you talking an inch or a foot and what pattern size?
May find this interesting as well.
http://castboolits.gunloads.com/showthread.php?2605-The-Muzzleloading-Shotgun-by-V-M-Starr

 

[Britsmoothy]

I'm saying nothing. I'm not going through it all again.

 

[Treestalker]

Oh PLEEZE Mister Brit! I Missed it the first 297, 381 times! No; Wait! It's coming back! Half a jigger of 4fg (DuPont de Nemours) a hand full of tweed yarn rammed tight, half a hand of lead shot and an overshot wad (1/2") soaked in Superglue!

 

[Britsmoothy]

Oh PLEEZE Mister Brit! I Missed it the first 297, 381 times! No; Wait! It's coming back! Half a jigger of 4fg (DuPont de Nemours) a hand full of tweed yarn rammed tight, half a hand of lead shot and an overshot wad (1/2") soaked in Superglue!

Close but no cigar. I meant a good flat file.
The OP only mentioned shooting clays so I held back on half a cup of 4f to the oz of shot

 

[Gun Tramp]

(1oz powder, felt wad, 1oz shot and overshot card).

One ounce of powder? No wonder black powder is in short supply.

 

[oldwood]

I'll post this again since it's been awhile. We got the Pedersoli sbs shotguns when they first came on to the market. Did extensive experimentation to find a wad column to obtain the tightest shot pattern as the goal to use for hunting. Powder was FFg , wad was one "edge lubed" .125 , or .250 card wad on top of the powder. 1/2 of a .125 card wad went on top of the 1 1/4 oz shot. The powder was measured w/the shot measure by volume , equal amounts. Experiments showed this gave the tightest patterns , since the light card wads dropped out of the shot cloud more quickly , than using fat fiber cushion wads as used in higher pressure modern shotgun ctg's.. . One additional thing , we found that due to the lower velocity encountered using black powder , going up one shot size than would be recommended for ctg. shotguns. It was a significant help in longer range killing power. We shot ringneck pheasant , rabbits , and squirrels w/ Pedersoli shotguns loaded like this. Same applies to the 10 ga. Pedersoli sbs shotguns as well. .......oldwood

 

[Widows Son]

Thanks for your help. I’m new here and I don’t mean to be an annoyance. As I said, there is lots of reading in here. Evidently this question hit a nerve.

 

[Feltwad]

The boring off repros including the Pedersoli can vary , for mine when I use it the load is has follows 2..3/4 drams of 3 FFg powder 1/.8 card wad , 1 felt wad, 1/8 card wad , 1.1/8 oz of shot followed by 1/16 card wad . At 25yards this load should be spot on target and kill upland game stone dead if not sell it .
Feltwad

 

[NorthFork]

@Widows Son

Don't mind the grumps on the forum. Sometimes folks here forget that at one time they were new as well.

There are numerous ways to make a cylinder bore muzzleloading shotgun throw patterns that range from 'spreaders' to nearly full choke like patterns. What will work for you involves experimentation. Here are some tips/hints to get you started-

1. Search the forum for the SkyChief loading technique. Simply searching for SkyChief will net you hours of reading. This will enable you to have nearly full to full choke like patterns.
2. More lead, less powder will tighten the pattern. More powder, less shot will spread the pattern.
3. Harder shot will produce better quality patterns.
4. How you use the various components and what kind of components (wads, cards, etc) will change both the quality of the pattern and the size of the pattern.

As for low and to the side, well it could be practice is needed. Your eye is a shotguns rear sight. Your cheek position on the stock and eye in relation to the center of the bore is critical and needs to be absolutely repeatable. If additional practice at a patterning board does not produce results then maybe some muzzle tweaking is needed. PM @Britsmoothy for details on how to best do this. How far off is the POI vs POA? Hope this helps.

 

[Grenadier1758]

A paper shot cup can tighten patterns as well. Use a Post-It note with the sticky edge. Make a cylinder from the Post-It Note that just slides into your shotgun bore. Make the cylinder as long as the shot column. Load the powder then start the over powder wads. Insert the paper cylinder, pout the powder and insert the over shot card or the well lubricated wad (SkyChief wad) and ram the charge to the breech. The paper holds the shot column together a bit and keeps the shot from rubbing against the barrel to deform the shot and this spread the pattern. Upon leaving the barrel the paper falls away effectively acting as a choke.

I have made a former from a 3/4" dowel rod that I turned down so that the paper wrapping will be a slide fit in the barrel. Make a poor man's lathe for this by marking the center of the dowel rod. Insert a screw into the dowel rod and cut off the head leaving enough of the threaded end to chuck into your hand drill. Use your drill to turn the rod while you use a rasp to remove excess wood until the paper wrapped twice around the rod will just slide into the barrel. Wrap the paper around the rod leaving just enough extra paper to fold over and make a cup. Just before loading, wipe the outside of the cylinder with a lubricant to help soften the fouling from the previous shot.

 

[hanshi]

Thanks for your help. I’m new here and I don’t mean to be an annoyance. As I said, there is lots of reading in here. Evidently this question hit a nerve.

Widow's Son, you are NOT being an annoyance and your posts are welcome. This forum is meant to offer (and receive) advice on anything smoothbore related. You've received good advice to ponder over and trying out Skychief's load is a great place to start. Welcome!

 

[SmokepoleSam]

Look in the "Traditional Muzzleloading Hunting " forum it's a sticky right at the top

 

[Britsmoothy]

Hello all, I hope everyone is well.

There is so much wonderful information on this forum that it can be hard to wade through. Pardon me if this is an already answered question.

I’ve got a 12g Pedersoli sxs made in 1985, both barrels are cylinder bored. I just shoot clays using #7.5 and #8 chilled lead shot.
I’d like to know how different loads (powder charge/wads/shot) can change the spread or point of aim? It seems that at 25 meters it shoots a little low and right. My usual load is square (1oz powder, felt wad, 1oz shot and overshot card).

I know there is no substitute for actual range time and experimentation. However black powder is rather expensive and hard to get at the moment so I’d like to have some ideas of where to start rather than hoping I’ll get lucky.

Regards
Joe

Most Pedersoli shotgun doubles are not regulated via shooting tests before they leave the factory.
Most believe this is done by soldering and unsoldering, adjust and then resolder the barrels. It's not.
It's done by simple file or beveling of the muzzles and is very slight.
I have successfully corrected POI on three muzzleloaders and two breech loaders.
Also. The casual observer can not tell a thing!

 

[SDSmlf]

Most Pedersoli shotgun doubles are not regulated via shooting tests before they leave the factory.
Most believe this is done by soldering and unsoldering, adjust and then resolder the barrels. It's not.
It's done by simple file or beveling of the muzzles and is very slight.
I have successfully corrected POI on three muzzleloaders and two breech loaders.
Also. The casual observer can not tell a thing!

It seems that at 25 meters it shoots a little low and right.

@Britsmoothy is correct that a shotgun POI can easily be moved with a file. That is how my grandfather showed me. Remember my uncle and I thinking he was crazy until he demonstrated it worked.

Your gun shoots low and to the right, say your pattern is centered at 5 o’clock facing the target. File a slight angle across the face of the bore, removing a bit of metal at 7 o’clock (facing the barrel) across to 1 o’clock, removing no metal there. Your pattern will move towards where you didn’t remove any material (high side of angle), 11 o’clock facing the target. Suggest you confirm POI with at least 5 shots into the same target before and after any adjustment. The center of your POI will be obvious. Never tried this with shot cups, so no comment on what would happen if you are using them and tried this.

 

[NorthFork]

At the risk of running afoul of Zonie, the proper way to determine the POI vs POA of a modern cartridge shotgun is to bench the gun on sandbags fore and aft, shoot at a target 13 yards away from the muzzle, the target is a large sheet of white paper with a simple plus sign drawn on it with a sharpie say 1' tall and wide, shoot at targets several times using best form. The distance the center of the tight pattern is away from the + can then be mathematically figured for 30 or 40 yards. This eliminates all human error and wind deflection of shot. I'll hunt up the formula for you all.

No sense in reworking the gun until you positively know the amount of error.

 

[SDSmlf]

At the risk of running afoul of Zonie, the proper way to determine the POI vs POA of a modern cartridge shotgun is to bench the gun on sandbags fore and aft, shoot at a target 13 yards away from the muzzle, the target is a large sheet of white paper with a simple plus sign drawn on it with a sharpie say 1' tall and wide, shoot at targets several times using best form. The distance the center of the tight pattern is away from the + can then be mathematically figured for 30 or 40 yards. This eliminates all human error and wind deflection of shot. I'll hunt up the formula for you all.

No sense in reworking the gun until you positively know the amount of error.

I believe this is correct for bench shooting, but I have found my shotgun POI changes when I shoot from a normal stance when compared to shooting off bags. Guess my ‘best form’ from bags is not duplicated when shooting offhand, likely not anchoring my cheek on the stock the same. I tend to point a shotgun rather than aim it. Only interested in where my shotgun hits when I am shooting from normal shooting position. Just my opinion.

 

[Britsmoothy]

At the risk of running afoul of Zonie, the proper way to determine the POI vs POA of a modern cartridge shotgun is to bench the gun on sandbags fore and aft, shoot at a target 13 yards away from the muzzle, the target is a large sheet of white paper with a simple plus sign drawn on it with a sharpie say 1' tall and wide, shoot at targets several times using best form. The distance the center of the tight pattern is away from the + can then be mathematically figured for 30 or 40 yards. This eliminates all human error and wind deflection of shot. I'll hunt up the formula for you all.

No sense in reworking the gun until you positively know the amount of error.

Waste of time and powder and shot.
I just take a file with me to the pattern board.
I think last time I did a Pedersoli double it's was three attempts and then I went hunting. After gun cleaning I cleaned up the file work and never looked back.
Later on with the same gun I made a mandrel to jug choke the same gun and that worked to.

I don't find issues like these fix themselves no matter how hard I wish so I just get on with it!

 

[Treestalker]

Thanks for your help. I’m new here and I don’t mean to be an annoyance. As I said, there is lots of reading in here. Evidently this question hit a nerve.

Please pay no attention to the disparaging remarks made by the men behind the screen. Britsmoothy knows I am an admirer of his profound abilities with smoothbore guns in the field. What we do is rag each other for amusement and to keep a quantum of levity on the forum, for domestic and foreign relations and to assist new shooters to become proficient while providing an atmosphere of fraternal inclusiveness. Welcome aboard!