sleepysquirrel2
Member
- Joined
- Dec 17, 2020
- Messages
- 43
From Dupont's own instructions, published in 1904.
"Other guns do better work when a slightly smaller charge is used, so as to leave an air space of about one-quarter or three-eights of an inch between the powder and the base of the bullet."
In fact, the good old Ordnance Department's Frankford Arsenal would load 45-70 practice cartridges just like this, with a big 45-70 case filled with 20 grains of powder, 50 grains of air gap, and then a 240gr 45 cal revolver bullet.
Air gap causing guns to rupture is a myth, any handloader will tell you that decreased seating depth = lower pressures. The same is true with black powder: try it for yourself with some handlodaed blackpowder wadcutters, seating some flush (no air gap) and some out (with air gap).
All the stories /photogrpahs of people with "bulged barrels" from shooting black powder because they left an "airgap" always suspiciously consistent with someone seating a full charge, and then short starting another bullet, in essence creating a muzzle-loaded squib. Of course shooting any bullet into a bore obstruction will bulge the barrel.
"Other guns do better work when a slightly smaller charge is used, so as to leave an air space of about one-quarter or three-eights of an inch between the powder and the base of the bullet."

In fact, the good old Ordnance Department's Frankford Arsenal would load 45-70 practice cartridges just like this, with a big 45-70 case filled with 20 grains of powder, 50 grains of air gap, and then a 240gr 45 cal revolver bullet.

Air gap causing guns to rupture is a myth, any handloader will tell you that decreased seating depth = lower pressures. The same is true with black powder: try it for yourself with some handlodaed blackpowder wadcutters, seating some flush (no air gap) and some out (with air gap).
All the stories /photogrpahs of people with "bulged barrels" from shooting black powder because they left an "airgap" always suspiciously consistent with someone seating a full charge, and then short starting another bullet, in essence creating a muzzle-loaded squib. Of course shooting any bullet into a bore obstruction will bulge the barrel.