I have 125g field points that I shoot right now I was just wondering if I should shoot the same weight in broad head or should I go with 100g I am looking for penetration more so than speed. thanks

It's best to shoot the same weight to avoid tuning/spine problems.
And a heavier broadhead usually flies better and more weight equals better penetration IMHO.

Definatly shoot the same weight broadhead as field point.

I agree that you should shoot the same wieght field point as broadhead. If your shooting the hypershocks and want the best penetration then the 100's would be the best choice. They are smaller and therefore will penetrate better. You may want to re-tune the bow with 100 grn points if penetration is what your looking for.

I'm going to buck the norm here and say that I have started liking a little heavier FP than broadhead ............due to the typical broadhead being longer than a fp (changing foc and spine slightly) !

If your broadhead choice is one of the shorter versions.........I'd stick with the same weight !

When making decisions on tip weight, spine should be taken into consideration. If the arrow is stiff enough, I always like shooting heavier tips. They will help a fixed blade broadhead fly better, and will help all broadheads in wind or when hitting small twigs or grasses.

The difference in flight trajectory is minimal when moving tip weight up or down 25 grains.