I would go wood handle. The head weight is the same, but the overall hammer weight will be less than steel or fiberglass, so the swing will be more effective for driving a framing nail, and you arm will like it more too.
Smooth face hammers are not meat tenderizers like the milled faces are, so they won't tear the skin off as easily, but they are not flat faced either. The convex smooth surface of the smooth faced hammer will make contact with the nail head in one small area and stick to it as well as any new milled face hammer. The face will not be damaged from using hardened concrete nails like the milled face is. And once a milled face is worn smooth, it works like it was originally smooth anyway. If the hammer is making contact with the nail-head in more than one spot the sticking power is reduced exponentially by the increased striking area of the head face and is more likely to slide off and hit the wrong nail. So the transition time from new to worn smooth is the most dangerous to your fingers with the milled face hammer.
Also, a good technique to learn is to set the nails with a light glancing blow, or a shallow eliptical swat, that moves the hammer head away from the thumb and fingers during/after the strike. I find that holding the nail point off the surface a little helps set the nail also, by giving it a little punch speed before it meets the surface. The added space provides a little more overall escape room for those fond fingers and the smooth face will not grab the nail head sideways on the starter swat.
Keep a rhythm too. Three swings on a framing nail is not bad, two is better, and a light to-the-side tap to keep time while fumbling the next nail into position. The sound of money making framing music, nails a'popping and saws' a singing. :thumbup:
Cuss'n yo hammer, is not part of the song. :no:
Good luck in school!
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