A Slug Gun is a muzzle loading bench gun that shoots a paper patched elongated bullet from moderate powder charges, from 100 yards out to 500 yards at Friendship Ind (home of the NMLRA), I have shot these guns for twenty years.
They come in weights (historically) from 10 pounds to 100 pounds, the average today is around 35 to 40 pounds. Almost all have false muzzles. Calibers from .36 to .68, bullet weights from 250 grs to 1750 grs. Average today are .38 to 50 cal. most shoot .45 cal of about 520grs to 540grs.
We use paper patching mostly strips, some use chase patches usually about .003" to .005". Lubricated with oils such a sperm, bear, mineral or what have you.
Most use a sealed ignition using modern rifle primers (some pistol primers). We shoot Blackpowder usually 2f no pyrodex (yuck!)
They will shoot inside MOA. One must become an accomplished wind reader as well as other conditions such as light and mirage, and be aware of temperature and humidity changes.
The bullet is custom made for each rifle and can be of one or two pieces, the two piece has a base of pure lead and the nose is of an alloy. Most shoot two piece but there are those who swear by the one piece and therein lies a raging controversy
I shoot two piece.
We shoot with target scopes as they did in the 19th century and is one reason Slug shooting is called an old man's game. Most of the competetors have 15 or more years experience in other venues but have developed eye problems that make open sights invisible. In other words the Slug Gun Shooting at Friendship has some really tough competetion
The Guns are a lot of work to shoot and maintain and takes a very dedicated shooter to enjoy them. Most do not like to make bullets and cut patches etc and fall by the wayside.
Hope this gives a better insight to what Slug Guns are about.
Ed