20 Ga. Slug Load LEE Mini Bullet

[Sliver Shooter]

I maybe am reinventing the wheel but I've been scratching on paper, doing some number scrunches. I'm looking at loading some 20 Ga. slug loads using the LEE 540-415-M Single Cavity Mold Mini Ball. I measured my bore which was .615. Measured my wad (AA) which has peddle thickness of .036 x 2 = .072. This gives me a slug diameter of .543. If I'm figuring correctly, the wad and mini ball would be .612 diameter. If the slug mold drops them at .540. I can adjust with some paper on the slug as needed. The slug is hollow based so a 28 ga. wad in the shot cup should correct having issues. Do you think I'm figuring this right? Attaching a pic of the slug.

[W.R.Buchanan]

If you are going to run this thru a Rifled Barrel it might work OK. You'll have to try it and see. I would try to get the Slug Diameter up around .617-8 so it had a good tight fit in the rifling.

It will not work with a Smoothbore Barrel.

Randy

[longbow]

I will start by saying that I am not a 20 ga. guy so have not done this. However, a former member here used to post loads of info showing slug/wad fits and he had several examples of .58 Minies in 20 ga. wads. Unfortunately most if not all his posts have been deleted.

So, the short story is it will work with the right comnbination of .58 Minie and wad petal thickness but as Randy said, for rifled bore only. The Minies will not stabilize from smoothbore. A rifled choke tube on a smoothbore should work.

There is some info here:

https://castboolits.gunloads.com/sho...-58Cal-Bullets

You will need a pretty tight fit for the rifling to transfer spin through the wad to the slug.

A google search may turn up post on other sites and search here should also find some more threads because this is a fairly common topic.

Longbow

[Hogtamer]

I had the same thought a few years back, just never could get it accurate enough for me out of rifled gun. Never could figure out why it didn’t work.

[centershot]

I was pretty happy with the Lee .575" RB in a Commander wad for my 20 ga. M500. As said, you'll need to be pretty tight (over bore size) in order for the rifling to impart spin to the projectile. You might want to fill the base with hot glue to keep the skirt from deforming. Or just use the round ball.......

[Sliver Shooter]

Looking at my figures, which in reality are never on the nose, to make bore size I would need to paper patch the slug, which is supposed to drop at .540, with .003 - .004 paper. That's awful thin. Maybe cigarette papers. Together with the wad would match bore size. To make a tight squeeze to grab rifling, how much should one add? I know I could just go buy some saboted 20 gauge rounds but for 1. the only ones I've found to group well in my 870 with full rifled bbl. is the Remington Accu-tip. I have some but to buy more, they are awful high priced. Besides I enjoy a challenge to do it myself.

[rsrocket1]

Make sure your wad petal measurements include any ribs along the petals. I recall the Winchester AA 12 GA wads had a vertical rib in the petal which bulged the hull when I seated a Lee slug in it. You may still be shooting knuckleballs out of the gun with no spin on it but it may be good enough at 25-50 yards.

The fun thing about trying these things out is no matter what, you still get to go out and shoot!

[W.R.Buchanan]

There are other options here. How about a 20 ga. Lee Slug? They are designed to be loaded in a normal shotgun wad, I have gotten decent results with them out of both Rifled Barrel and Rifled Choke Tube. Certainly good enough out to 50 yards. Also there are versions of the Lyman 525 Style Slug that are available in both Wad versions and Full Bore versions. However once again these are going to be 50 yard loads. There is also the option of a Round Ball either loaded in a Wad or there are Full Bore versions of those as well.

The reason why those Mini ball boolits you were looking at wont work in a Shotgun is because they are designed to be fired in a Rifle where the base of the boolit is exposed to the powder charge and is Expanded to get a tight fit in the bore when fired. You can't get that type of expansion when the wad is blocking the base of the boolit from seeing the full pressure of the powder. Also your loads will be in the 10-12,000 psi range which is way below what a Rifle operates at.

One last thing the Boolits are aligned perfectly aligned with the bore of a rifle when fired. In a shotgun wad they will ALWAYS have some misalignment with the bore. This is why Slugs like the former Slugs R Us and now Leon's R Us Slugs work so well. They are over bore size and have a long bearing surface to align them with the Bore and are Very Weight forward as well. See the pic of this 5 shot group with Slugs R Us from a Hastings Fully Rifled Barrel at 50 yards. It is 1 x 1.5 and the first three shots were the Cloverleaf!

Also note the other target shot at 25 yards with Lee Slugs and a Rifled Choke tube from my M500 and the other slugs mentioned above as well. They would still provide "Useable Accuracy" out to 60-70 yards

Hope this gives you some options to look at.

Randy

[Charlie Horse]

I admire people who can get good results with a hand-loaded slug. I cannot.

[centershot]

When I decided to load my own "slug" loads it was after a lot of research here. I decided that a round ball was more likely to provide success, versus the other available options. I'm not saying that a minie ball won't work, just that you'll probably need to do some work on your own to make it work. One thing that I found was that if you are using a plastic wad as a sabot you need to understand from the start that a wad is a POOR sabot! I tried lots of different wads, I settled on the Federal 12S3. It is a "tough" wad, well designed for what I wanted to do. The crush section held up well, as it should, since I was loading the equivalent pressure of a 3 dram trap load. You might think that oter wads would hold up as well, they didn't. In 20 gauge I found the Commander wad to be a really good choice when couple with a .575" RB or a 577" minie. Both loads carried a 28 ga. nitro card under the projectile. These wads may not hold up if you load them above their normal pressure windows. I settled on 1300 fps as being all I need from a "slug" and was happy with the results. Another thing I found was that nothing worked until the "sabot" was over bore size. I think the ball was slipping in the wad when the wad was spun by the rifling, unless it was tight enough in the wad to be held securely.

Here's what worked for me:

https://castboolits.gunloads.com/sho...tershot+sabots

[centershot]

Here are the fired wads. Note that even though some petals were cut or sheared off, the rounds still grouped well!

[Sliver Shooter]

I have looked for a LEE 20 Gauge mold and have yet to find one

[longbow]

That would be because Lee doesn't make a 20 ga. slug mould.

From the Lee site:

"We made some prototype 20 gauge slug molds, and sent sample slugs to the powder manufacturers for testing, but following unfavorable test results we decided not to produce the 20 gauge version."

I can't imagine it being difficult to produce a 20 ga. Foster style slug mould but there is their comment anyway.

Lyman makes a 20 ga. Foster slug mould but like the 12 ga. Foster mould it casts undersize at 0.605". Why Lyman make moulds to cast undersize "bore diameter" slugs escapes me. Oh well!

I guess that constutes thread drift! We are not talking Minies in shotcups anymore! To add to that thought, as mentioned, the fit of Minie in shotcup has to be pretty tight to transfer rifling spin to the slug without it skidding inside the shotcup. Knurling or paper patching would both bring up diameter if the .58 Minies are a bit small, which I think is an issue.

Longbow