Sheesh
I have slugged lots of barrels. That guy makes it look a lot more difficult than it has to be. I get nervous when anybody is using a hammer near the muzzle, even if it is a soft hammer. And I will also tell you it is not absolutely necessary to lube the slug either. I have slugged plenty of barrels with a dry slug. I have used everything from a soft lead ball, to a fishing weight, to a hard cast bullet, they all work. I have never used a wooden rod, too easy to crush or break. I start the slug with a short brass rod about 6" long. Easy to hold onto and keeps the hammer away from the muzzle. When the short rod is almost all the way in I switch to a long rod about 3 feet long. Simple, easy peasy. Takes about 5 minutes to slug a bore and that includes set up time. The key is to use a slug big enough to completely fill up the rifling of the barrel. If the slug does not show drag marks on the high spots, which coincide with the grooves, than it probably did not completely fill the grooves and the measurement is suspect. Easy to slug a barrel with an even number of grooves, just measure across the high spots with a caliper. More difficult with an odd number of grooves (most S&W barrels) because you can only measure from high point to low point, and then you have to measure the height (depth) of the grooves and add that on. Tough to get that accurate. There is a technique for slugging barrels with an odd number of grooves that involves using a V block to measure and doing some calculations, but I have never gotten the hang of it.
Let's talk 32-20 for a moment. The Winchester Model 1892 in this photo was made in 1911. the S&W 32-20 Hand Ejector on the left was made in 1916. The Colt Police Positive Special 32-20 on the right was made in 1926. I have no problem putting modern Smokeless 32-20 Cowboy ammunition through any of them.
Any idea exactly what 32-20 S&W revolver you have? I may be able to help date it if you know the model and Serial Number. If you have a good photo I that would help too.
Anyway, loading Black Powder into a cartridge is super easy, you are making it harder than it needs to be. You simply pour in enough powder so that when you seat the bullet it compresses the powder between 1/16" - 1/8". That's all there is to it.
How to determine the correct amount? Here is a technique I have used for years. You make a little ruler out of a small stick. you place the end of the stick at the crimp groove on a bullet, and make a mark at the rear of the bullet.
Like this:
Then you place the ruler with the mark at the mouth of the case, and pour in enough powder so that it covers the base of the ruler by about 1/16" to 1/8". That's all there is to it! No remarks about the fingernails, those are the lovely Mrs Johnson's fingers who held the little ruler while I took the photo.
Or, you could use your caliper to measure the distance from crimp groove to base of the bullet, and then use the extension dohikkey at the end of the caliper the same way. Pour in enough powder so the base of the extension dohicky is covered by about 1/16" - 1/8" of powder.
It really is that simple. You have now determined the correct amount of Black Powder powder for that bullet. Then you pour it out into the pan of your powder scale and weigh it. Yes, I said weigh it, don't listen to all that guff about you never weigh Black Powder. You now have determined the perfect weight of the powder charge for that bullet in that case. NOTE: unlike Smokeless powder, not all brands of Black Powder weigh the same. They all weigh a little bit different. So you have determined the perfect weight of powder for that bullet and that brand and granulation of powder.
Do yourself a favor, buy a set of Lee dippers:
https://leeprecision.com/powder-measure-kit.html
Cheap and well worth the money. Throw away the sliding rule that comes with it, or just ignore it, I find the data on it is mostly incorrect.
Use the above technique to select a Lee dipper which gives you the closest to the ideal 1/16" -1/8" compression. This is not rocket science, it does not have to be exact.
I use several different Lee dippers when I set up for loading cartridges with BP, I select the one that works best for the cartridge in question. I have some custom dippers I made from spent cases soldered to a brass wire.
When using your dipper always use a consistent motion to dip out the same amount of powder each time. Use the dipper like an ice cream scoop to scoop up the powder, then scrape off the excess with a piece of card.
I load Black Powder on a progressive press, and I have several powder rotors set up for my standard loads. But dippers work fine if you are loading on a single stage press.
If you are loading on a single stage press, all you need is a set of dippers. My old single stage Lyman Spartan press is set up for 45-70 in this photo, but it would work fine with 32-20 too.
This is what the guy at Old Eynsford was talking about. The case on the left is an old Balloon Head case. The case on the right is a modern Solid Head case. These are both 45 Colt cases, but the idea is the same for all cases. You can see the Balloon Head case has more interior volume, so it would take more Black Powder to fill it up than with a modern case, Balloon Head cases have not been made for a long time, so this is not an issue.
Primers:
You really need to buy a reloading manual. Stop looking up stuff on the web and actually buy a real book and READ IT!
You are confusing primers with loading dies. Primers are the little button shaped thing you press into the primer pocket at the rear of the case. When a firing pin strikes them, they send a flame through the flash hole to ignite the powder charge. You can see all that on the sectioned cases in the photo above.
Modern 32-20 cases take Small Pistol Primers. Period. Not Small Rifle Primers or anything else. Small Pistol Primers. You can use any brand, Winchester, Federal, CCI, it does not matter.
Reloading dies are the metal tubes you shove your cartridges into to load them. This is a set of 32-20 dies. Notice there are three dies in the set. Other types of dies only have two dies, but for 32-20 you need three. This is a set of fancy RCBS Cowboy Dies. It is not necessary to buy this set, any brand will do, these have a couple of features that make it slightly easier to load. Notice I keep a few dummy cartridges, without powder or primers in the box, in case I have to reset the dies for any reason. Also, notice there is a shell holder in the box. The gray, round, steel piece. This does not come with a set of dies, you have to buy a shell holder separately, and they are specific to a particular cartridge. One other thing: Some die sets come with a carbide ring in the bottom of the sizing die. This means that case lube does not have to be used with them. Tapered die sets, like 32-20 are not available in a carbide version, so case lube must be used on your cases or they will probably get stuck in the dies. No fun, trust me on this.
Bullets: because tubular magazine rifles have the point of one bullet resting against the primer of the cartridge in front, you do not want any sort of pointed bullet loaded into a cartridge that goes into a rifle with a tubular magazine. You can use any bullet style in a revolver. Forget gas checks. You don't need those. They are to prevent the rear of the bullet from being softened by the hot expanding combustion gasses. Plain lead bullets will serve you fine. Standard bullet diameter for 32-20 is .313. Don't sweat it if your barrel slugs a little bit larger or smaller, .313 will be fine. Let me know how you make out slugging that S&W barrel which probably has an odd number of grooves. Most usually have five grooves.
One other thing about bullets. If you use standard off the shelf bullets with Black Powder you will probably build up a deposit of hard fouling in the grooves which will quickly degrade accuracy and be difficult to remove. For all my Black Powder cartridges I use bullets with a soft Black Powder compatible bullet lube. I used to pan lube my bullets with a mixture of Crisco and beeswax. These days I buy my bullets from a guy in California who casts them special and lubes them with his own home made bullet lube.
P.S.Regarding the difficulty of loading WCF cartridges and splitting the neck of crumpling the case. Yes, all the WCF cartridges: 44-40, 38-40, 32-20, and 25-20 have very thin brass at the case mouth. Thinner than say 45 Colt. That is just the way they are. So yes, you have to be very careful setting up your dies with those cartridges, the brass is not as forgiving as loading cartridges with thicker brass at the case mouth, such as 45 Colt. I set my dies very carefully, with these cartridges.
Here is a trick I learned a long time ago. When I set up my dies for any of these cartridges, I leave a hair of space between the top of the case mouth and the underside of the top of the crimp groove in the bullet. This is a 44-40 round, but the trick works for all the WCF cartridges.
As the ram of the press shoves the case up into the seating/crimp die, the brass 'swallows' the stationary bullet. If the die is set so the tippy top of the brass bumps into the underside of the crimp groove, something has to give. What usually happens is the brass at the mouth gets shoved down and crumples below the bullet. Like this. I actually set the dies to exaggerate the effect.
If a hair of space is left, say about .005 or so, the brass stops rising up and does not get shoved down from butting against the top edge of the crimp groove. When setting up my dies I simply measure a few cases, and select a few that are the longest by a few thousandths to use when setting up my dies. Then any slightly shorter cases will be guaranteed not to bump into the underside of the crimp groove.
The other thing you have to remember when loading WCF cartridges is do not rush. If you raise the ram quickly, and the case is slightly off center in the shell holder, the mouth of the case may strike the bottom of the die. A more robust case, like 45 Colt would shrug off the insult, but a WCF case will probably get mashed. The solution is simple. Slow down. That way if you feel a case bump into the bottom of the die you can stop the stroke before any damage is done to the case. Simply straighten it out, and guide the case mouth into the die with one hand and no damage will be done to the case.
I always say, loading WCF cartridges is not difficult, but it is fussy. You have to set your dies up just right, and you have to slow down.