Lee 1 oz slug data

[Randyralph]

Good day all. I just started reloading shot sheels, after reloading rifle and pistol for the last 25 years. The question I have is can you take a 1 oz slug made by Lee, and use the same data you would use for a 1 oz shot load, keeping in mid that the wad may need to be changed in order to obtain a good crimp. Anyone ever try this?

[Unclenick]

Take a look at Lee's instructions for their slug molds. The loads are not the same as you see listed in their shot instructions of the same weight. The powders listed tend to be slower than those they list for 1oz. shot loads in their 12 gauge charge tables. This suggests the slug tends to raise pressure over the shot. I haven't thought through why that might be. It is likely to be determined experimentally.

[Poodleshooter]

Sort of. It's safe so long as you use 1oz shot data EXACTLY, and then substitute a slug,provided you can get a satisfactory crimp.
The problem is that the drive key slug takes up less room than 1oz of birdshot in the wad. This means that it doesn't fill up a 1oz shot wad very well, which can interfere with getting a good star crimp.

[Unclenick]

Lee refers to filler wads as optional, but doesn't change the load suggestions for using them. I'd have to put a strain gauge on the shotgun barrel to be sure, but I'd be careful about the quicker powder loads until I was certain there wasn't some unexpected dynamic involved. The slower powders recommended are actually going to be more demanding of a good crimp than the faster ones will.

[snuffy]

The question I have is can you take a 1 oz slug made by Lee, and use the same data you would use for a 1 oz shot load, keeping in mid that the wad may need to be changed in order to obtain a good crimp.

NO! Slugs act more like a solid, than the more "liquid" shot charge. Meaning, the shot can be compressed and move a little, lessening pressure. The hard, solid, slug then needs a slower powder to allow for possible spikes in pressure. Remember, shotguns run at much lower top pressure limits than handgun or rifle. 11,000PSI for 12 gauge, most are well under 10,000.

Get the slug mold, it will have a loading sheet included with it, or try that link above. You WILL have to cast them yourself, I know of no one that makes them for sale.

[Poodleshooter]

NO! Slugs act more like a solid, than the more "liquid" shot charge. Meaning, the shot can be compressed and move a little, lessening pressure. The hard, solid, slug then needs a slower powder to allow for possible spikes in pressure.

Isn't this what the wad is for? Shot compression as a function of the area it compresses must surely be insignificant versus wad compression.
Also, shot compression must vary considerably with shot type,yet I've not seen it taken into account in load data (aside from buckshot). A load of nickel plated BBs for example would compress far less than a load of #9 dead soft lead. This leads me to believe that it's not a major factor in pressure due to wad compression being a far more important factor.

It's a pity we don't have a hodgdon engineer or someone with pressure barrels around to tell us these things!

[snuffy]

Poodle, where in a slug do you see air spaces? It's a solid, it can't compress.

A shot charge is in constant motion from the time the primer pops, till it stops at the target. It HAS to change shape and shorten when it begins it's journey from the shell, into the chamber, then into the forcing cone and then the cylinder portion of the barrel. Then it encounters the choke, it has to compress again to reflect the degree of choke restriction the barrel or interchangeable choke tube has.

If you load shotshells, look at a shell that has the required weight of shot in the wad, BEFORE it's crimped. Then fire that shell, pick up the fired wad. You'll notice the shot was up to the top of the wad in the uncrimped shell. BUT the shot is only touching the wad about ¼ inch down from the top. It compresses down when under acceleration, like it was a fluid.

Slugs can't/won't do that. So the pressure is higher, no give to the payload.

Shotshell reloading is very unforgiving. Shotguns are made much lighter in construction, and operate at much lower pressures. Small changes in powder and primers can easily exceed the narrow safety window. Follow the recipe exactly. Substitute one component, pay the price!

[Stumper]

I know this thread is old but I was browsing slug threads. Snuffy is applying some good reasoning....but I think came to the wrong conclusion. Testing shows that slugs produce LESS pressure than the same weight of shot given identical components. The reason probably lies in the very thing Snuffy was discussing-shot charge fluidity. Shot is not truly fluid but in hydraulics/fluid dynamics pressure impinges equally in all directions. The "fluid" nature of a shot charge means that sidewall pressure against the wad petals/ barrel walls may approach breach pressures .Thus there is a LOT of friction as the charge starts up the barrel. A slug is more static. it may obturate some to fill the bore or swage down some in the forcing cone but it typically won't have nearly as much friction against the barrel walls on the trip up the barrel-at least that is the theory explaining why tests show reduced pressure when slugs replace shot as the payload.