Building a heavyweight high FOC crossbow arrow

[jedman]

 I am looking to build a crossbow arrow of at least 900 grs. and could be more. My plan is to use a heavy carbon shaft that weighs 10.5 grs. per inch, use a aluminum half moon nock , a brass or steel long insert I will make on the lathe of 250 - 300 grs. and have a 200 gr. 2 blade single bevel broadhead. To stiffen the spine and add weight I also plan on filling the entire ID of the shaft from the top of the point insert to the bottom of the nock with clear casting epoxy. This should make the spine of the shaft off of the charts stiff as a crossbow arrow doesn’t need to flex to fly properly from a crossbow according to AI.
 I had another plan to use the same 22” shaft with .300 ID and .345 OD and insert a 300 spine carbon shaft with a OD of 7.6 mm or .299 OD but am going to try the epoxy filled shaft first.

 I plan on running these through different tough targets to see if they break, shatter, or anything fails before I use them to hunt with.

 I would like opinions as to what other think of this idea or offer other ideas I may try.
This arrow would be for Cape Buffalo and I don’t like it when I see an arrow sticking half way or more out of an animal. According to Dr. Ashby 650 grs. is the minimum weight for a serious arrow and I plan on a bit heavier since my crossbow should shoot this at over 250 fps.
 jedman

[Graybeard]

I've heard of using an insert shaft into a larger shaft for the purpose of increasing weight for such tasks. I suspect trying to fill the shaft as mentioned with epoxy is going to leave voids that will affect the balance of the arrow in flight.

The shaft within a shaft idea is proven to work and I'd go that route first.

BTW good luck on that quick second shot at the charging buff when the first one fails to put it down.  :'(

[jedman]

I've heard of using an insert shaft into a larger shaft for the purpose of increasing weight for such tasks. I suspect trying to fill the shaft as mentioned with epoxy is going to leave voids that will affect the balance of the arrow in flight.

The shaft within a shaft idea is proven to work and I'd go that route first.

BTW good luck on that quick second shot at the charging buff when the first one fails to put it down.  :'(

Thanks for the quick reply Bill,  I couldn’t find how you reply so I hit the quote and that seems to work.
I will experiment with adding weight to the arrows and testing as the hunt in S Africa is not till September 2026.
The epoxy I have is the type that people make clear tables from with objects inside and it is formulated so bubbles exscape but until I try I will not know. As far as getting charged by the buffalo after shooting a arrow into or through him ( preferred ) I guess they have PH’s using stopping rifles if needed BUT I don’t plan on shooting any buffalo that sees me or know I even exist first of all.  I have seen many videos of Cape buffalos shot by arrows either from a blind at a water hole or out in the bush from a downwind area and they typically don’t react to wildly after shot, if there are others with it they seem to know something just happened and trot off until the one shot decides to lay down. Many only go a short distance but nothing is predictable with these big guys.
 This is only going to happen IF there is a cull animal available as I am going to hunt regular plains game and the buffalo would be a big IF IT is available. I just want to have a couple arrows that are capable just in case.
 jedman