12ga slug loading?

I built a 12ga purcusion using a modern barrel and a tim allen action. I have the lyman 12 bx hollow base slug mold that produces a 500gr 705 dia. slug. The slug slides down the cylinder bore on it's own weight. If i try to load it in a shot cup it won't go down. What would be the best way to load it for accuracy? Maybe use a over the shot wad to keep it on the charge, or paper patch it.

I'd certainly try just the base wad, but I'd be also be tempted to try paper patch it to bring up the diameter to near bore-size, whether with actual paper or plumber's teflon tape.

Would it be possible to patch it with ticking like a ball?

bore is .728? slug is .705, .023 difference. Would a .010 lubed patch crunch up enough around the edges to hold the slug in place on top of the over powder wad and maybe a cushion wad?

marmotslayer said:

Would it be possible to patch it with ticking like a ball?

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That's another good question worth testing. It would certainly be more convenient.

Bottom line in my eye and from my limited experiments with Forster slugs in my 12, the closer you can come to a tight bore fit, the less likely for the slug to tumble. I experienced tumbling (visible on paper even at 25 yards) with bare slugs in my own shooting, but gave up before pushing far down the wrap pathway. My shooting was mostly out of idle curiosity than any aim to develop a load for regular use and hunting.

I was more than a little discouraged by the bore leading I experienced with the bare slug, making it seem near-mandatory to protect the bore somehow, whether or not a base wad was also used.

I don't want to put any wadding above the slug to interfere with accuracy but don't want the slug to move at all while hunting. Teflon tape or patch would be doable. I thought about Skychief's loadings using a lubed cushion wad over the slug "accuracy?"

You don't want to use plastic shotcups with blackpowder as they will leave a mess in your bore.
Regardless of what wadding you try under hollow based slug, it will stick IN the slug and cause accuracy problems.

Simpler would be to use a .68" or.69" roundball and patch it.

excess650 said:

You don't want to use plastic shotcups with blackpowder as they will leave a mess in your bore.

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I'm not advocating use of plastic wads because I don't think they're necessary. But years and years of using them in the past helped me learn an easy fix for plastic fouling if anyone wants to use them. Just put a lubed fiber or felt wad under the plastic cup. The lube nicely resolves the plastic issue.

Simpler would be to use a .68" or.69" roundball and patch it

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This ^^^^^.
This is what i do with my 16 gauge fowler.

pete

Looking at slugs fired from modren shot guns and ball out of my fusils I see about the same groups. A prb can be loaded with or with out a wad and shoot well, you don’t have any worries about it slipping off the charge.
PRB are unknown historically, maybe. However it’s in a lot of use and works well.

william l evans said:

If i try to load it in a shot cup it won't go down. What would be the best way to load it for accuracy? Maybe use a over the shot wad to keep it on the charge, or paper patch it.

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The reason it won't go down in because your barrel probably has a choke....

I would use a .69 caliber round ball and a patch....You can get a mold from Lee cheap.

I have the mold and the slugs were cast some time back for my 870. The barrel is a modern cyl bore blank and was cut at the breech end in front of the chamber, then threaded for the breach plug. If I can get it to shooting good enough to hunt with it, I will be happy.

Colorado Clyde said:

william l evans said:

If i try to load it in a shot cup it won't go down. What would be the best way to load it for accuracy? Maybe use a over the shot wad to keep it on the charge, or paper patch it.

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The reason it won't go down in because your barrel probably has a choke....

I would use a .69 caliber round ball and a patch....You can get a mold from Lee cheap.

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Not all shotcups are the same thickness. I shoot RBs from a Lyman .662 mould in my double with .725" bores. It works very well with Federal 12S3 and 12S4 wads. I tried .680" in other wads, but they were mostly a too tight fit. It wouldn't have been possible to load them from the muzzle.

Following BB's use of a lubed cushion wad under a plastic wad to prevent plastic fouling, it might be necessary to remove the petals, partly or completely, to allow the slugs to be loaded. It might be necessary to insert a 20ga nitro card inside the cup to prevent the plastic from wedging inside the hollow cavity. Making slugs of this type work is a combination of support and alignment. Maybe a lubed cushion over the powder followed by a nitro card, and then the slug with a single wrap of thick paper or thin card stock would achieve the desired fit.

You will do better with patched round balls.

william l evans said:

I have the mold and the slugs were cast some time back for my 870. The barrel is a modern cyl bore blank and was cut at the breech end in front of the chamber, then threaded for the breach plug. If I can get it to shooting good enough to hunt with it, I will be happy.

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If the mold is a foster type mold it was designed to be used without a shotcup. Only lee and lyman sabot type molds are designed to be used with a shotcup. Even then they are not designed to be muzzleloaded. Most wads are slightly larger than the bore and most slugs are slightly larger than the wad internal diameter...

If you are dead set on using a conical slug load it using hard op wads and os cards.

I'd still use a round ball, I even use them in my modern smoothbore shotguns. because they are more accurate than slugs.

Thanks everyone for your input. I will get a roundball mold and try that out too. Whichever one is most accurate, I'll use.

Look at a round ball it has a ring of contact surface. Even Minnies and Maxis have rings or are under bore size with expandable skirts.
You may can load a slug in a clean bore but any fouling....forget it.
Some rifles are slug guns but smooth bores are not as forgiving as rifles in this aspect as they have no grooves.

54ball said:

You may can load a slug in a clean bore but any fouling....forget it.
Some rifles are slug guns but smooth bores are not as forgiving as rifles in this aspect as they have no grooves.

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Very true. :thumbsup:

One of the explanations I read for the first rifles was groves were cut to make a place for fouling to go when fired with a near bore sized ball. The first twist was done to make more grove length then the length of the barrel. Then the rifle was born.
I don’t know that I buy that explanation :wink: but it was a good story.
I swab between shots. It adds little extra time to the reload. Should a clean bore accept your slug, it’s no big hassle to wipe so it will accept your slug.
That said I think you will be happy with the patched ball.

tenngun said:

One of the explanations I read for the first rifles was groves were cut to make a place for fouling to go when fired with a near bore sized ball. The first twist was done to make more grove length then the length of the barrel. Then the rifle was born.
I don’t know that I buy that explanation :wink: but it was a good story.

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Remember the straight rifling discussion?

I swab between shots. It adds little extra time to the reload. Should a clean bore accept your slug, it’s no big hassle to wipe so it will accept your slug.
.

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The problem is his slugs .715 diameter.... that's too big for a use with a shot cup. Even a .69 caliber round ball will fit tight in a shotcup. simple calipers and some math with provide all the answers one needs. measure the projectile and the thickness of two shotcup petals and add them together....it cannot exceed muzzle diameter.

Modern shotgun barrel chambers have a forcing cone to them that swages everything. trap shooters often lengthen that cone for better patterns and reduced recoil.