I've been hunting with carbon arrows with Wenzel Woodsman 125 grain solid steel broadheads which weigh around 430 grains total and have a FOC measurement of 16%. I've been reading that the ideal FOC for hunting arrows is around 9%. Would adding weight to the nock end of the arrows possibly improve their flight consistency (grouping), with which I have problems, assuming that their spline was heavy enough? Would this increase or decrease penetration?
I don't know where you got that info but Easton reccommends 10%-15% for hunting arrows and many are finding that FOC in the 20%-25% gives GREAT flight and penetration. Weight to the back end is supposed to increase the dynamic spine but I haven't seen proof of it. Weight on the front weaken dynamic spine. The FOC is not the source of your issue,unless you are border line weak with the shaft and the 125 gr head puts you over the limit. Yes,weight on the back will decrease FOC.
What are your arrow specs? Specifically your spine. tfox, you can increase the spine by adding weight to the rear, but keep in mind, it's all a numbers game. I had a 350 spine arrow and had to use a quickfletch on the rear (adding weight) to get it to tune. However, that hurts the FOC.
Thanks Thanks for the replies. I did not know that adding weight to the back of the arrow would increase the spline and I don't think I want to do that. It seems like I have to have my bow weight close to 70 lbs. to get good paper test results as it is with 29 inch Goldtip 5575 XT Hunters.
The spine of an arrow is a set value. It cannot change. There are things you can do to manipulate how the spine reacts. You can move weight around, change length... ect. The key is in the tuning. You can create the best theoretical arrow you can contrive, but if it won't tune in your bow it's worthless. Luckily, there are tons of choices in arrows. I was having a broadhead flight issue when I went to 125s. I was using a 350 spine arrow with a 125 up front and quickfletch on the rear. I would shoot perfect bullets through paper. In order to achieve the perfect bullets I had to go from the typical 3 blazers to a quickfletch, thus adding weight to the rear. The broadhead flight was fantastic at 20 yards. After that it was all downhill. The arrow would take a dive. I ended up moving to a lightweight 300 spine arrow. This kept the weight where I wanted it and gave it the spine to tune well and perform well past 50 yards with a broadhead. Those arrows were the gold tip velocity pro 300s.
