Every so often we see mention of very light loads and gun blow-ups, usually in the context of developing ultralight cast bullet rifle loads, or subsonic squibs with light bullets.
I use these very light loads for several purposes including target shooting. My rules are to use lubed soft lead bullets and fast burning pistol/shotgun powders, and to run enough velocity not to stick a bullet – just subsonic seems reliable. Plated bullets can stick at low velocity. I am also suspicious of hard cast bullets.
The gun blow-ups are said to occur in part from a combination of unsure ignition and start stop bullet movement.
An interesting experiment to try with your intended squib powder is to place 5 gns or so on the ground, load a primed case (in a rifle), place the muzzle about 6” back from the powder, and touch off. Ordinary rifle powders generally are just scattered by the flash without igniting. Something like Red Dot will ignite nicely, despite being over two feet from the primer.
I reason that if powder on the ground will ignite that far from the primer, then I don’t have to worry about it not going off in the cartridge. Conversely I see more reason to worry about a small charge of slow rifle powder.
As an aside, these squibs can probably be used as fire starters if you have with you the means to pull a bullet, i.e. pliers or Leatherman tool. Set up your kindling, tip the powder in where it’s needed, and flash with the primed case.
Happy New Year to all.