Yes. It probably will not work, due to differing rates of barrel rotation around the axis when fired.
Getting the barrels to point at the same impact point is not the same as getting them to shoot there.
If you read my long thread here you will see the part where I thought that I had hit on a better solution as well.

In the end the best and surprisingly easy to achieve solution was with two square blocks with 1/2 barrel diameter machined into them separated by a slow taper wedge. Set barrels parallel and at the same height vertically with the wedge in the central position. Solder up. Use the top of the wedge as the foresight. Shoot and adjust by heating and tapping the wedge up or down accordingly. Twist barrels in relation to one another ( see the tool in "Building doubles on shotgun actions") with solder hot to adjust vertical dispersion.
I used a strong spring stretched around the barrels to give tension whilst softening the solder to stop every thing falling apart.

Regards