Where did I say that? Perhaps I should have separated the statements better. I guess I assumed people would understand the muzzle device doesn't effect burn conditions because that's a rather odd thing to suggest. Is that your best attempt at a lame gotcha? Extending a member slows it's response, longer windchime lower frequency.
Hot powder burns faster resulting in shorter barrel time.
Extending the mass on the barrel slows it's response, withdrawing the mass on the barrel speeds up its response. So you extend the mass/member lenght to match time to exit for a slower burn and shorten it to match a faster burn to retain the same exit phase.
Unless
@Macht I have upset your plans for bringing quantum entangled powder charges to competition?