The 75 Gr. Steel BH Adaptors

[Dr. Ed Ashby]

Andy,

Thanks a bunch for the pics. I've neither seen nor encountered this problem with either the trad bows or the compounds. I'd love to get whatever details you can remember; complete arrow setup and specifics of the hit. Where did you get the inserts? It appears that are fairly long. Are they 100 grain ones?

I'm with you 100%. No one should be using arrows that do that, not even occassionally. If hunters don't make a fuss when we need something that works better, it doesn't seem that very many manufacturers are going to take the initive to seek and find better products for our use. I'll probably never get there, but I seek perfect, absolutely reliable terminal arrow performance; every time, on every hit - whatever that requires.

Ed
TGMM Family of the Bow

[tradtusker]

Ed i will e-mail you with the details, pics and what i can remember  

[Dr. Ed Ashby]

Thanks Andy. Very much looking forward to getting them.

Ed
TGMM Family of the Bow

[Dr. Ed Ashby]

Andy, I'm sure glad a few other folks are starting to show up with this problem with the 75 gr. steel adaptors. I was beginning to think someone had sent a TOKOLOSHE after me!

Ed
TGMM Family of the Bow

[flightmedic]

tradtusker tell me about your testing, what were you shooting at , etc, just curious

[fyrfyter43]

Ed, I have a half-dozen of the 75 grain steel adapters here that I just got from 3 Rivers about 2-3 weeks ago. I will take them to work tomorrow and take measurements as you have, and then mount some broadheads to them and see if I can experience the same type of failure you have.

[Yolla Bolly]

Dr. Ashby---Thank you for the alert.  There is about eleven arrows in my quivers that are going to loose their heads quickly. The other of the dozen disappeared over a coyote's back into canyon full of poison oak.   :eek:

[J from Denmark]

Ed, there is two problems with the steel inserts that have been on the market the last two years or so.
1 is the one you found with the 75 grain version

the second problem is that both 75, 100 and 125 are much thinner then they used to be, between the threaded part and the shank and will break like on tradtuskers pic.

Maybe the ones Mike Walker bought is better. they look like it. And Bobw had better meseaurements on them too !

The problem with the steeladapters arose when they thinned out all the models, so they easily could make 75 grain versions on the same "basemodel"

    :(

[BobW]

Likely the "cost of production" of having long and short versions resulted in the idea to just core out the long adapter to get the mass down - hence only 1 set-up.  The "short" 75's appear to be a stout piece of material.  Funny thing is, the style I have were purchased because they were more economical (yes, cost less), than the ones you have.

Ed,

I had inquired before as to any experienced issues with a short adapter.  Any disadvantage to them?  I do agree, a titanium insert would be the ticket.

[Dr. Ed Ashby]

Eric, it will be interesting to see what your measurements come out to be.

Jacob, yes, it certainly looks like something is amiss. I'm going to check out some of the adaptors Mike showed.

If you look back to the 2007 Update Part 2, you'll see a photo of the first bent 125 gr, steel BH adaptor that I recorded in all the hundreds of test shots. Until this problem with the 75 gr. adaptor popped up, it had escaped my attention that the bent 125 gr. adaptor was one of the new ones, with the thinned down shank. Perhaps the weakness problem extends to the other adaptors of this design too, just to a lesser extent.

Bob, I haven't used enough of the short adaptors to really speculate on what effect they would have . No doubt they would leave the forward portion of the BH's ferrule unsupported; presenting a potential weak point. I do remember, many years ago, when folks were using short tapers on both wood and aluminum arrows for the Bear Razorheads (so there was room for the bleeder blade to  pass through forward of the taper) it was common to have BH bends and ferrule collapse just forward of the taper. Bear came out with a little saw blade for slotting shafts, to allow for more ferrule support and correct the problem.

Ed
TGMM Family of the Bow

[J from Denmark]

Ed, regarding carbonshafts breakage :
Have you tried Carbons with HIT inserts ?

They need a sleeve on the outside to withstand direct preasure as well as standard carbons but I think they might be stronger regarding breakage behind the insert !

And they have smaller diameter too !

Jacob

[Dr. Ed Ashby]

Jacon,

I've used the thin shafts, but not with the HIT inserts (I used 'outsetrs'). Howwever, I have a couple of friends that now have Extreme FOC's setups using them. Now I'm just waiting to see how they do on Georgia pigs and deer. Might have to wait a while though. They've promised test shots after any kills too.

All the carbons I've worked with show a weakness back of the insert, especially on angular impacts. I'm really hoping that the prototype Internal Footings work out. I'm a bit guarded about the materaial, simply because it's exotic, and I know nothing at all about its characteristics. The engineer's computer modeling says it will work great. I understand that it is used as a repalacement for steel bearings in certain high-pressure applications though. That sounds encouraging. Will know for sure after I try to destroy them - and the sdhafts they are in!

Ed
TGMM Family od the Bow

[fyrfyter43]

I tried to measure the adapters I have, but I couldn't measure the depth with the caliper I have on my desk at work. The depth gauge is too wide to fit inside the taper. However, the straight-line length of the taper ranged from 0.650" to 0.654", averaging 0.652". I can also see that the counter-bored hole is conical.

A rough measurement using a #8 machine screw shows the depth to be the same as the length of the taper. When you consider that the machine screw will not reach the bottom of the cone (due to its diameter), I think it's safe to say that the counter-bore is slightly deeper than the taper length.

I do believe that these adapters are the same design as those you have experienced failures with.

I tried a quick test as you did by mounting a 175 grain Hex Head to these adapters, and striking them against a work bench by holding the arrow shaft at about the mid point. I did not experience any failures.

[J from Denmark]

I hope they will make thoese IF´s availble for HIT arrows too !
HIT arrows need a 0.75" alusleeve on the outside but when that is done, they will outperform regular carbons in my experience.
J

[Dr. Ed Ashby]

Jacob, I THINK the initial plan is to develop IF's for the standard shafts first; GT's, CE's. etcetera. Once those are perfected, I expect that attention will be turned to the others.

I'm not sure how much IF design difference the thin shaft would require, but the principle should be the same.

Ed
TGMM Family of the Bow

[Dr. Ed Ashby]

Well, there has been no reply from 3 rivers regarding their 75 gr. steel BH adaptors. Must admit that I'm a bit disappointed.  I expected a bit more concern.   :confused:

On the up-side, the 75 grain adaptors from Kustom King, such as those shown in Mike’s and Bob’s photos on page 2, do have much greater steel thickness in the area of shank attachment to the taper, and didn't snap off when I rapped them against the steel workbench.    

Time permitting, I’ll try to test those out during this year’s testing. For now, there seems to be enough who have noted a problem that it’s probably best to avoid using the weaker adaptors for any serious hunting. It COULD cost you an animal, and there’s no reason to gamble an animal’s life when there is another option readily available.    

Ed
TGMM Family of the Bow

[TexasAg]

My uncle did some testing with a 190 Grizzly and 75 grain adapter this weekend. He was unaware of the problems with these adapters, and when he shared his results I figured I would pass them along...

On one attempt he stuck "test" javelina in the skull and although the broadhead lodged in the skull the adapter broke off at the same point of failure discussed above. The shaft continued on and slapped up against a nearby watertank. The other two shots went clean through the front chest cavity and the second through the loungs.

He was shooting a 65# PSA with 680 grain arrows

[oldbohntr]

Just to add another incident to the conversation, I had a 75 grain insert break at exactly the same place a couple of weeks ago.  Shot a judo into the muddy ground from a bear stand and the insert snapped.  I didn't hear it hit anything hard, and didn't dig deep enough to determine if it actually did hit anything but mud!  Thinking further, I wish I'd done so.  That's the only failure in thousands of shots, but it is troublesome.  I'm going to be working with the 100 grain from now on, even if I have to grind a bit of taper length off of it.

[Benny Nganabbarru]

Well, despite having used the 75 grain steel adaptor with no problems, today I witnessed this exact problem when my mate shot a boar through the lungs, and the broadhead hit the off-side shoulder. It was such a neat break.

In future, when shooting carbons, I'll be swapping my 100 grain brass inserts for 50 grain brass inserts, and using the 125 grain steel adaptors.

Hopefully I'll get some photos up later.

[Al Kidner]

Cheers Ben, I'll keep and eye on this thread. I'll be playing with some new Arrow Dynamics HammerHeads as soon as they turn up.


al.