mhay wrote: I’ve been thinking on this problem for some time . It realy hit home as I was building front end of my arrow with the STEEL broadhead adapter , and STEEL broadhead. That aluminum insert sucks.
Then in my post yesterday about PLAYIN’W/FOC , Mr. Petersen stepped in with his thoughts and mentioned the weak link . His comments got me to thinking again . So , I pulled a broadhead off the shaft ,,,,,dug out a new aluminum insert .Here’s what I found .
I.D. of insert at the shank area of BH adapter = .204 inch.
O.D. of adapter shank,,,,,,,,,,,,,,,,,,,,,,,,,,= .196 inch.
Is it the unsupportered space between the insert wall and the shank of the adapter causing the weakness?
Is it the simple fact that the insert is too short ?
Or a combination of both and the insert being aluminum ?
What do you think ,,,,,or know ?
Bent adapters is not isolated to aluminum .Some have experienced the same problem with steel. Bending of steel adapters is generally associated with heavy arrows (750 grn +) hitting large bones. I do not know what the actual cause is as I have been doing tests and can not duplicate the bending of steel adapters.
I beginning to think that upon impact of the broadhead that the adapter thread make up with the insert is jarred enough to break it loose and create a small gap which allows it to bend …..Just a theory as I have not been able to duplicate it.
I do not recommend a aluminum inserts as they are to soft and really prone to bending. (for what ever reason that causes it)
For most hunting in the USA a steel adaptor of 100grn or 125 grn would be my choice. These are still not fool proof.
Bending of the adapter upon impact more than likely will hinder,slow, or retard good penetration.It is important to try and bomb proof the WEAK LINK AREA
For large game such as moose and buffalo or large african game I believe titanium adapters with a extended adapter (part that fits in 5 degree taper.)should be used. Grade 5 titanium has twice the tensile strength as steel.The reason I say it should have a long taper is there are some titanium adapters that have short tapers similar to the 75 grn steel adapter and other aluminum
adapters. Until someone can isolate the reason for bending I would stay away from short tapered adapters.
There is an other alternative to the screw on adapter and that is a adapter/insert combination. This option eliminates the threads and any potential gap between the broad head and arrow.I have no reports of this alternative creating problems. For large game the adapter/insert and a footed arrow would eliminate most potential problems.
This bending problem is not just isolated to glue on broad heads with adapters.It is also happens to broadheads that have the threads built into the head,
which should lead to some conclusion???????
I hope some one can shed some light:idea: on this problem as it is driving me up the wall:D