How heavy should I buy my arrows?

[DeerHunter08]

So my brother and I are getting into archery hunting for deer I have a 45# bow and he has a 50# bow. I know these are fairly light poundage bows and I've been trying to do some research about arrows and know that momentum is key to penetration, but I can't figure how heavy my arrows need to be. I've heard micro diameters arrows help penetration?? We don't want to buy super expensive arrows until deer season gets closer next year, we just want some arrows for practicing. Any advice and tips would be greatly appreciated.

[bowhunter75richard]

You did not give info as type of bows; traditional or compound. If traditional, arrows need to be spined 5 pounds heavier than bow weifgt. A 45# bow would require a 50# arrow spine. The weight of the arrow itself in grains should not be too light as a light weight arrow, though maybe faster in speed will not penetrate as well as a heavier arrow. If you are inquiring about compound bows, I am afraid I have no info for you !

[PAShooter]

As bowhunter75 says, you do not give enough information. Type of bow, draw length, and broad head will be some variables. Research on internet for arrow spine charts.