Not every 3-Gun 930 begins life as a JM Pro. Our first Mossberg 930 competition guns were built from the SPX or Turkey models, long before the JM Pro came on the scene. In fact, we still run the SPX for night matches and have a Turkey model pulling duty for the occasional match. In an ongoing series of work being done to convert a 930 Snow Goose for 3-Gun, we will look at some issues that can crop up with adopting a different model than the JM Pro for competition. While legal (if not practical) out of the box for Open, the 930 Snow Goose model needs some changes to run in Limited or Tactical Optics. Before the JM Pro, there weren't any 930 models with longer than an 18" barrel that weren't also ported. This is an instant kick to Open in most 3-Gun rule sets. The common solution was to cut 4"-6" from the end of the barrel to eliminate the ports and re-thread the gun for chokes. This can create a problem on a gas shotgun. A 28" barrel on a Mossberg 930 has different sized gas ports than a 22" model and these cut barrels would sometimes create cycling issues. The reason is simple, but often overlooked. The dwell time has changed and the amount of gas available for the gun to cycle has been reduced as a result. It was common thought that the cure was to run hotter loads. Unfortunately, a 'hotter' load is sometimes only a faster load, with the same powder charge and lighter shot weight, so the actual dwell time is reduced even more. It is important to have properly sized gas ports in relation to the barrel. Keep this in mind if you go the cut and re-thread route on a longer barreled Mossberg 930. For this installment, we have cut a spare barrel for this gun down to 22". While 24" is more common and possible to do after fully eliminating the ports, this gun will be run in Limited (or Factory) with its 8-round magazine tube restriction. This should end up as a compact, easily maneuverable 930. Stay tuned!