Ohh, thread drift over...

.355 or .356 -- they are used interchangeably. .355 is the traditional 9mm diameter, .356 is the traditional .38 diameter (I believe SAAMI for each caliber). You'll see major bullet manufacturers offering comparable products in either. For example, MontanaGold uses .355 for most the the 9mm/.38 bullets that are most popular. The most accurate .38 bullet that I have shot is the Hornady 121 gr. HAP which is .356 (still fully jacketed). It seems that most the jacketed bullets are typically in .355 and lead often in .356. Will there be an accuracy difference? That's where trying it in your gun is the best bet.