I'm reading an article by Bob Robb the other day, and did'nt believe some of his "spec's".He was talking about finding a happy medium with your arrow.A balance between KE and speed, and forgivingness.He stated that his bow,(I think he's shooting a LEGACY), shot 270 with a 387 or so grain arrow.He bumped up the weight to 443 and only lost "5" fps.He also GAINED like 6 more pounds of KE.
There's NO way that right, is there ??.

It's entirely possible, yes. Different bows handle different weight arrows differently. Some bows retain energy better and thus put more into a lighter arrow, some do not. Some work excellently with heavier arrows, some lose energy and speed with them due to their individual geometries and draw-force curves. Based upon your input, you have a differential of 56 grains. The normal average of speed loss is 6 grains of arrow weight for every 1 foot of speed, so realistically he should lose around 9.3 fps, not 5fps. BUT, as stated, every bow and setup is different, so 4 feet is not out of the realm of things in any way.If he can use a heavier arrow and gain KE and produce a quieter shot with less vibration thru the system, 5 fps is definately worth it IMO. Good shooting, Pinwheel 12

Hi numbers do seem a bit off but anything can happen. Like Pinwheel 12 said each bow store energy very differently. I can see where he could get that but I wonder if he stretched it a bit, who knows for sure but him!

I agree most of the time that 5-6 grains per 1 fps is about right.