I think Arthur nailed it. The 250s sound right. As for grains per inch....that does not necessarily come into play in terms of getting the right arrow to tune out of your bow. Spine is more of an issue with that. What it does come into play with is your minimum grains per pound ratio for your setup. Considering your setup though and the grains per inch of those arrows I do not think it will be close to posing a problem.