After 300+ guns I find if you use quality parts you have no worries. If the lock sparks and the vent liner is installed properly I figure it ought to work.....and according to my customers they always do.
Years ago, about 1969, Roy Keeler quit proofing barrels since he had never had a Douglas fail and considered it a waste of time. Then one split up the top flat for about 8" the first shot from a new rifle. He went back to proofing barrels.
He made the mistake of sending a report to MB magazine and then Douglas would not longer sell him barrels. He had to buy them third party... I am told. I used to by parts from him and he ran barrel channels for me.
Douglas ML barrel was considered a quality part and still is to some.
I have a trust by verify attitude.
Dan