I have my arrows flying pretty good bare shaft, and with feathers shooting a 225gr field point. However, the broadheads that I would like to shoot on these arrows weigh in around 240grns, I also have some that weigh in around 215 grains.

I guess my question is how much will the lighter or the heavier broadheads affect the spine of my arrows? Would it make a noticeable difference to shoot the heavier broadheads? Would it be worth my time to shorten the arrows a little to make them fly a little stiff with the field points to make up for the 15 extra grains of the broadhead?  Thanks guys!

Shoot and find out, but I doubt you notice much of a difference.

It seems to bother people mentally more than physically....Unfortunately, I'm one of those people  

How much difference does 10-15 gr. make?

I think if you'll try both the combinations you mentioned you'll see little or no difference in POI from the lightest to the heaviest. Shoot them before you cut the shafts for sure.

Ron

Would it be wise to shoot the broad heads with the bare shaft?

NEVER shoot broadheads with a bare shaft. They can plane and go wild.

Broadheads and bareshaft can be very dangerous with erratic flight. If your perfectly tuned with the 225gr you may get good flight with the other weights, depends on tune, center shot and arrow type. Shoot the various broadheads with field points to see if they group well.

Thanks guys, I'll give it a try tomorrow.

The further your bow is cut from center, the more of a difference you should see...theoretically at least...LOL.
As has been said, give it a whirl and let us know.

One thing that could make a difference is if you're shooting carbon arrows or not. Most carbons tend to be better at NOT noticing slight changes in point weight when compared to other arrow materials.