I realize the POI will change but how about the accuracy? Will your .5 gun still shoot .5 after a barrel swap? Do you have any special method to assure accuracy?

I am building a new 2 barrel rifle. One stock, one action, 2 quality barrels with the same contour and 2 different calibers. I am wondering if the sweet spot load will change when I change barrels. I realize the headspace can/will be off by .0005 to .001, will that effect accuracy?

Bill