I'm going to be taking a ML instructor course but regarding the 'air gap' issue the course material seems fixated on 'NO AIR GAP' period (I get that if seated too far before powder it might act as an obstruction). Maybe it's just the lawyers speaking. Now I'm not so regimented as to believe everything I hear and feel, at times, there MIGHT be more than one way to do something. So rather than swallow hook, line and sinker the dogma in this course I'd like some practical, reasoned experience and observations.
When muzzle loading, all I ever hear is seat bullet down on powder. Now (and I know this is breech loading not ML) but powder, bullet remains the same...so why can you get away with 'air gap' in breech seating and I'm being told 'you'll blow up your gun' if done with a ML????
I know in certain types of BP mortars there is a air gap between ball and powder and there can be an air gap when breech seating. I'm just trying to find out the reasons for and against, before I flunk the final because I'm not parroting the ML dogma because I've heard of air gaps being used and with fine accuracy in Schutzen games because of the breech seating.
Sorry for the long question but I'm just trying to understand. BTW I've never done breech loading myself just what I've gleaned over the years and perhaps I'm completely misunderstanding something. 

THANKS!!!

The vast majority of shooters who are breech seating are also shooting smokeless powders, which react differently to air gaps and wont cause a problem.

rgchristensen wrote on Mar 18^th, 2025 at 10:10pm:


In his book he states that he was unable to ring a chamber with black powder, but that he could ring one on demand with smokeless.

There is obviously something going on with ringed muzzleloader barrels as it's not at all uncommon, but I've shot a lot of breech seated bullets with black powder using air gaps of up to 1/8" with no problems.  These were all with CM barrels though, not softer original barrels.

Chris.

Vall, Charlie was able to ring a chamber with no wad just by shooting straight up in the air. The problem is caused by a powder surface parallel to the bullet's base whether caused by a wad on top of the powder (touching) or gravity holding the powder's surface level and parallel to the bullet's base. An overpowder wad is fine as long as it is slightly separated from the powder so that the powder can slump a bit. There must be some separation distance between the powder surface and the bullet's base more than when just the 1/16 or 1/8 from breech loading. It became apparent in smokeless charges that left considerable separation in cases originally designed for black powder. The effect of pressure build up is what makes shaped charges in antitank loads work. Naturally it is more serious in our old original barrels than new high strength steel ones but even those can have a ring build up through repeated loads. Why take a chance? Leave a bit of space between smokeless powder and an over powder wad (or wadding).

Speaking hypothetically, in terms of muzzle-breech seating with blackpowder, since shooting with a case full of powder is de rigeur why not seat the bullet so it bears firmly against the powder charge with a wad on top of it? I'm envisioning a full-to-the-brim charge of black with, say, an 1/8" greased felt wad smushed on top of it with a skinch left protruding, the whole works squeezed into the chamber to bear against the previously muzzle loaded bullet?

Untold tens of thousands, or hundreds of thousands of commercial black powder gallery loads, and the same too for arsenal black powder practice loads were made and shot in the era. These rounds had very small charges of BP in full sized cases. 

Indeed the current Black Powder Cartridge News has a piece called Vintage Revolver Roundball Gallery and Midrange loads that has historical loading data for many of the old revolver calibers, listing small charges of BP. 

The issue of short seated ML's by a few inches or more must be a different dynamic than the less than 100% full cartridges. It is all above my pay grade.   

how much concrete? thirty horsepower can probably get you and your car up to two hundred miles an hour. If you don't take the food and water you need to survive while it is getting there.

curdog wrote on Mar 19^th, 2025 at 8:27pm:


There are smokeless powders out there that operate at black powder velocities and do so at lower chamber pressures than BP does.