Mad Monk,
With the distinct possibility of real black powder shortages looming as a result of Goex shutting down the sole remaining plant come January 2022, I need to know if the use of a 10 grain squibb charge underneath any of the black powder substitutes, to include BH209, constitutes in any way a dangerous chemical reaction that could lead to excessive breech pressures?
My engineering mind tells me that it should be OK. Mainly because of the semi-open breech that results from the touch hole drilled into the side of the barrel.
If a shooter wishing to continue shooting his flintlock rifle is being faced with a diminishing supply of real black powder, but has access to an abundant supply of a black powder substitute; then logic might suggest that a pound of fffg black powder could be stretched out to approximately 538 shots per pound by utilizing 3 grains of powder to prime the pan of the lock, and 10 grains as a squibb charge to help ignite the substitute powder main charge.
7000 grains ÷ 13 grains = 538.462 shots per pound
Since most of the substitute powders generate greater breech pressures than does regular black powder, a reduction in the weight/volume of a shooter's normal hunting charge is obviously in order.
What my inquiring mind needs to know, and I am hopeful that you can answer, is when real black powder is used as a squibb load to ignite a substitute powder; does the combination of the two different propellants end up creating a dangerous pressure situation in the breech of a flintlock barrel.
Thanks.