Need Help with Lee 1 ounce 12 gauge slug loads

[Turbo]

I have cast a bunch of Lee 1 ounce 12 gauge slugs. Shooting them in my cylinder bore Remington 870 gives horrible accuracy. I tried them in my son's Browning pump with Improved Cylinder choke and had same results. Accuracy has been 6 - 8 inch groups at 25 yards from a bench rest.  I can shoot 1.5 inch groups with open sights on other guns so I don't think it's entirely me.

Here's my load data:
Federal Gold Medal cases, 14.8 grains Clays powder, Federal 12SO wads, Lee 1 ounce slugs, CCI primers.

Fiocchi cases did the same thing.

The loaded rounds look good, with a good crimp.

Do Lee slugs have to be shot in a rifled bore?
Anyone have a good load for Lee slugs in a smooth bore?
Should I get a different slug mold and skip the Lee?
Do I need to roll crimp?

Thanks! Any help would be GREATLY appreciated.

[c mac]

I also just bought a Lee 1oz. mold.  Go to loadyourown.com and check out posts under shotgun projectiles. I will have more there after I get time to fool with it.
c mac

[Leftoverdj]

Count me in the race.

I am just getting started with Lee slugs Results not worth posting yet, but better than I ever got with Lyman.

Go vote for our own slug gun forum.

[Robert]

I am looking for a rifled barrel for one of my Shotguns, However, I do not like the cantilever systems that I have seen.  I can't see how to acheive accuracy with a scope mount that will flex up and down with the re-coil.  So...I am considering maybe trying to get one for my New England, because the breech of the barrel is in the right place to mount a conventional scope base.  Also thinking about getting the Lee slug mold.  12 gauge slugs are one of the most awesome things in the world to shoot.  A never ending source of delight and satisfaction.   Ha Ha.

[c mac]

Robert
I think you're right.The scope may flex with recoil. But the shot is off at that point. I see rifle size groups with this setup. It does work. 'Am I right guys?
c mac