Need Assistance - Measurements on the Snapping Steel Adaptors

[Dr. Ed Ashby]

I've added this information on the 75 grain steel BH adaptor thread, but figure some won't check there. It's beginning to appear that there is a vast construction difference between some of the 75 grain Bh adaptors on the market. The ones I got from 3 Rivers have proved very fragile, and prone to failure.

Here are the measurements from those I have, which are snapping apart with alarming frequency. See the '75 grain steel adaptors' thread for full details.

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MEASUREMENTS
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Ok, borrowed some vernier calipers from Harrold. He's a retired machinist/metal worker, so pretty good at precise measuring. Here are the dimensions we're measuring on the 3 Rivers 75 grain adaptors I have.

(1) 'Straight line' length of the taper (outside): 0.650"

(2) Depth of the counter-bored hole at the center (Check photo of broken shank, on page 1. The counter-bore has a conical termination): 0.671" (Note that the center of the counter-bored hole extends 0.021" beyond the taper - actually extending that far up into the metal of the shank.)

(3) Depth of the counter-bored hole at its edge: 0.640"

This means the calculated thickness of the metal holding the shank to to tapered portion of the adaptor is 0.010". That's ten one-thousands of an inch.

The "break-ring" showing on the shank(s) is so thin that neither Harold nor I could accurately measuring it with the vernier calipers; to verify the calculated thickness of attachment. However, we both did a visual comparison of the break-ring's width to some feeler guages, and both came up with 0.010". Appears to be an accurate measurement of the thickness of steel holding the adaptor's shank to its tapered portion. That is far, far too thin, by anyone's standards.

Ed
TGMM Family of the Bow

[Bowmania]

Just wondering what your doing to make them break???

Bowmania

[Joseph]

I believe he was shooting whitetails with them and not very large ones at that.  He tells more in the other thread he mentions.  Joseph

[Ga.boy]

Link to original thread:

http://tradgang.com/noncgi/ultimatebb.php?ubb=get_topic;f=1;t=057304

[DanDaMan]

did anyone hear if 3 rivers has said who made these?  Are these just a batch of bad ones?

[Dr. Ed Ashby]

Dan,

I sent the link to the 'main thread' to 3 Rivers a few days ago. No reply yet.

Ed
TGMM Family of the Bow

[dino]

Dr. Ed,
I was in 3R today picking up some feathers and asked Dale if he had received an email from ya.  Said he hadn't.  You might try sending it again, must not have went thru. dino

[Dr. Ed Ashby]

Dino - or anyone else:

My email is on the fritz. I can receive but can't send anything. I just got back from my trip out to NM and south Texas. Can someyone - anyone - forward the main link on the 75 gr. adaptors to Dale at 3 Rivers for me? I'd hate to think that they are not aware of this problem.

http://tradgang.com/noncgi/ultimatebb.php?ubb=get_topic;f=1;t=057304

Thanks to whomever can help.

Ed
TGMM Family of the Bow

[BobW]

Isn't he member #1351?  Should be able to access this if interested.

[Dr. Ed Ashby]

Just want to be absolutely certain that 3 Rivers knows about them.

Ed
TGMM Family of the Bow

[dino]

Ed,
I did. dino

[Dr. Ed Ashby]

Dean, thank you very, very much. Greatly appreciated. I really hate to see any animal hit and lost due to a preventable arrow setup problem.

Thanks again,

Ed
TGMM Family of the Bow