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Stephen Graf
Post count: 2354

vintage archer wrote:

Do you recall when you retrieved your arrow if there was any sign the adapter loosened at the insert joint?

How heavy of a arrow were you using and how much wt forward. Just curious.

No way. After it happened the first time, I have always made sure there was no way the arrow would loosen (a loose broadhead seemed like the most likely cause). And I have studied the results when the insert bent, every time. What I have found is that:

1. The broadhead is undamaged

2. The shoulder of the insert is stretched an narrowed on the tension side of the bend.

3. The bend is in line with the plane of the broadhead.

I haven’t mic’d any inserts, but I wonder if the shoulder of the steel adapters is more narrow than aluminum adapters?

I have noticed that the relief between the body of the adapter and the shoulder is 90 Deg on steel adapters and 45 deg on aluminum adapters. I am sure this is a weight reducing measure. But it also reduces the strength of the steel adapters.

My guess is the problem is a combination of poor geometry and low carbon steel.

Arrow wt about 680 grn, FOC about 22%