Brent, there are several versions of MEC bars:
- The first ones had two holes, one determined the powder charge, the other the shot. The bars are marked to indicate the hole sizes. The bar of my first MEC delivered around 18-grs of Red Dot which worked for 12-ga target loads for many years.
- The next version of the MEC bars enlarged the powder hole to accept the familiar interchangeable bushings. The shot charge was still fixed. Later versions added an elastic buffer (for steel shot) in the shot hole.
An original bar shouldn't be a deal breaker.