Allow transition shoulders to match the diameter

[davesrocketshop]

As currently designed, the transition requires shoulder diameters to be less than the end diameter, as would be the case when used with a body tube. There are time's when it is desirable to match, such as when creating a mandrel.

[davesrocketshop]

As a workaround, the shoulder diameter can be very close to the diameter. For example:

Forward DIameter: 60.000 mm Forward Shoulder Diameter: 59.999 mm

[davesrocketshop]

Merged to main product