Yea, it doesn't take long for the powder to burn; a few miliseconds. I have a 13 inch (once inch of that is brake) Encore barrel in 375 H&H Magnum which would have more powder and it burns just fine.
Awesome. What bullet and powder are you running in it? for my .375 H&H the go to load was the Sierra 250 gr Game King over a healthy dose of RL-15.
How hard is the recoil in your Encore?