Have any of you ever disassembled a jackhammer?

There is an air cylinder much like a steam engine cylinder, except that the "piston" is free. The "piston" is a slug of steel that fits neatly in the cylinder like a piston. But in this case the "piston" is the hammer. Its mass strikes against the bit each time the machine cycles, thus producing the hammer effect. I suspect that Wright's "secondary projectile" is the loose wad in this case, which acts just as the slug in a jackhammer. A tremendous pressure is created when the shock wave of the powder burn shoves the loose wad into the base of the stationery bullet.

Who knows?

I tend to agree with .400NitroExpress that there is no use for squib loads in a NE double rifle.

Curl