A 230gr. bullet in a 40?????? Surely this must be a mistake. You must mean a 45. N350 will give you some of the highest velocity loads in the 45. There are a number of websites for powder companies that have loading data. Since you are new in loading, I would advise to get a couple of loading manuals and stick to the recipes exactly. DO NOT try to extrapolate. Loads for a 230gr lead bullet, a 230gr FMJ bullet, and a 230gr jacketed hollowpoint are likely to be quite different. Different brand primers can result in different pressures also.