Thread Differences in Investarms Locks

[Twosteels]

Alright, a question for the experts, Why are the Lock Bolt threads different for Flintlock, Percussion, locks for T/C and Lyman guns with in the same brand, I.E. example Lyman. (pictured). Was this just for marketing? The locks pictured do not have the same threads, The flinter is threaded 4-.70 mm. I always thought the percussion was threaded 8-32 but one of those will only thread in about 3/4 turn. The thread checker I have only has holes. The threads in the percussion lock could be 5-.80mm or 8-36. Anybody?

 

[Phil Coffins]

TC will be English and Investment will be metric. Each manufacturer will decide what to use and we must figure it out.