TE, There seems to be the misconception that there is less fitting to a mono-block than with the older shoe lump, and choppper lump barrels! This isn't the case, the mono-block must be fitted exactly the same way as the others. Anyone may reduce their cost of fitting by not fitting as closely as they should, the Mono-block has nothing to do with it. The worst place to cut cost,is in fitting, and that is one of the many places where the things like the $399 double cut the cost so they can sell for $399, but they can get away with less fitting on a shotgun, than on a rifle.

The only place mono-block cuts cost is,it is easier to machine a small square block of steel to it's basic shape. The fitting between the barrels of the chopper lump, is eliminated, but replaced by the threading of the mono-block, and barrel shank for fitting into the block! The fitting of the mono-block, to the action, is just as demanding as it is with a chopper lump.

The mono-block system can be applied to both types of double, as well as the chopperlump, so this isn't a decideing factor. The lump barrels are easier to join together in the O/U than the S/S. The top barrel is usually dovetailed to the bottom, and that is a simple machineing opperation. The rest of the fitting is much easier in the O/U, and the regulation is much easier done because you have only the lateral convergance to worry about, because both barrels are on the same lateral line. A simple twist here and there is all that is required to join the windage of their grouping.

However hand fitting, is hand fitting, and requires skill to do properly. Skill costs money, no way around it!