Trad Gang

Just a heads-up. Until recently I had not done any testing with either the 75 or 100 grain BH adaptors; only the 125 grain versions. The adaptors in this recent testing are all ones I bought from 3 Rivers.

There appears to be a fatal weakness in the 75 grain version. Several have broken, with the threaded section breaking away from the taper. I think the counter-bored hole in the taper on the 75 grain adaptor simply goes too deep, weakening the connection at the threaded shank. These breakages are occurring frequently enough that I think it is significant a arrow-integrity issue.

Ed
TGMM Family of the Bow

I can see how they might break being shot into heavy buffalo, but do you think they might be strong enough for lighter weight animals like deer?

Interesting find. I have only used the 125 grain versions myself... looks like I will keep it that way.

Kevin.

Russ, the problem was noted during some Georgia whitetail testing! I've not tried them on a buffalo - and don't intend to, after what the whitetail bones did to them.

Ed
TGMM Family of the Bow

Interesting info.  At the time the 75's were getting a work out, were you also testing the 100's?  I wasn't entirely clear on that from your post.

We have sold the 75's by the bucket load, all we've heard of is one fellow breaking one like you described hitting a rock.  If I understand you correctly they were actually breaking in the animals?

Tim,

Yes, but we haven't done as many shots with the 100 grain adaptors as with the 75 grain adaptors. However, no damage was encountered with the 100 grain adaptors in the initial whitetail testing. For sure, no more chance for whitetail testing until next year, but I have a dozed 100 grain adaptors I intend to 'punish' on some buffalo in this year's testing; to see if they hold up as well as the 125's.

Just FYI, both the 75 and 100 grain versions were tested with 100 grain brass inserts on Extreme FOC setups. They were used from a longbow and compound. Had multiple adaptor breaks on the 75 grain version from both bows.

Ed
TGMM Family of the Bow

How odd.....

Makes building 200gn broadheads awkward now, doesn't it?

Funnily enough the 75s is all I've ever used & I've stump-shot hundreds of them into trees, rocks, earthbanks & even one or two into animals! Never had one break/bend/fail yet.

Could we see some pics please?

It is all just a ploy to get us all shooting extreme FOC (I"M KIDDING!!!!!).

Thanks for the info Doc.  Something to look into.  Lots of us use 75's.

Not sure what this does to my arrow selection process.

BobW

Thank you Dr.Ed, fascinating.  I wonder if it's possible you have a batch with a hardness issue or something?  I've simply not heard that before but once.  I can see what you're saying though, the hollow cut out does go deep.

My limited first hand experience with them is similar to robtattoo's, I've not broke or bent one.

I have no idea how to test hardness myself, although I can perceive it fairly well when filing broadheads.

Interesting stuff indeed, thank you for the information.

IF ANY OTHER USER OF THE 75 GRAIN STEEL ADAPTERS HAS HAD SIMILAR FAILURES PLEASE POST ON THIS THREAD OR PM ME, I WOULD LIKE TO KNOW ABOUT IT.

Thanks, Tim

DR Ed, thank you sir. I normally use the 100 grain adapters with 100 grain inserts, and a 125 broadhead, but was thinking of switching to the 75 grain adapter. It sounds like you were testing a setup just like mine, and on whitetails too.

I'm very interested in how this thread turns out.

Okay, here are photos of one of the inserts. Every one looks like a carbon of the others. I double-checked the weight, and they are 75 grains (just being sure that the hole hadn't been accidentally bored too deep).


(http://i141.photobucket.com/albums/r53/ed_ashby/75grainAdaptor1.jpg)

This is the typical break. None of the adaptors show any bends to shank or taper. Note how thin the metal was at the area of break, shown by the width of the break line (Blue Arrow).


(http://i141.photobucket.com/albums/r53/ed_ashby/75GrainAdaptor2.jpg)

This is the inside of the shank; the portion that would be inside the hollow taper.


(http://i141.photobucket.com/albums/r53/ed_ashby/75grainAdaptor3.jpg)


This shows what the taper looks like after the break; just a tapered hollow tube.

Ed
TGMM Family of the Bow

Dr. Ashby,
I have the 190 and the 160 Grizzlies.  I am thinking that the 160's with the 100 or 125 grain adapter will be a better choice.  I say this because it appears that the shape of the 160 is more like your modified 190.  Narrower and still pretty long.  The adapter makes up the difference in weight between the 190 and the 160.    
Is there a reason not to go this route based on the research?
Richie

Richie,

Because of being shorter, the 160 has a somewhat lower MA than the 190, and much lower than the Modified Grizzly. In fact, if you modify the 160 by taking the cut-width to 1" and reducing the rate of blade taper by keeping the Tanto width the same, you end up with a minature El Grande - the exact same MA as the unmodified 190. Both have good MA, but the 190 is the higher of the two.

Ed

Dr. Ed, the pictures are great.  Thank you for posting it really cleared it up for me.  Based on your pictures my perception at this point is that it is an inherent design flaw.   :help:   It appears from your pictures there is very little steel at that breaking point.

Tim, that's my take on it too. It appears that the hole is just too deep. I think they would have been better off to reduce the length of the taper a tad more, and not have to make the hole in the taper so deep. For lower mass adaptors, sure would be nice if someone made one in titanium. Could be 'beefier' at the same mass.

Ed
TGMM Family of the Bow

I was just thinking that the 75 grain ones I bought would do well for some Wensel woodsman BHs I was gonna try! LOL not now!

Will get the 100 grain ones? are they still good or just go to the 125s?

J

Jason,

I haven't tested the 100 grain adaptors enough to be certain yet. They did fine in what little whitetail testing has been done with them. However, that is less than the testing on the 75 grain ones. I bought some 100 grain adaptors to take back with me, and will be doing some 'truly hard' testing on them this year, on some buffalo. If they stand up there, they won't have much problem on deer! All I can say for sure right now is that I noted no problem in the testing so far; which is too limited to make and conclusions.

Ed
TGMM Family of the Bow

Thanks Doc....Then I will really need to use the 125 adapters due to the weight the dremel will take off modifying the 160.  I will probably end up with around 275 grains.  And a total arrow weight of 740 grains pulling 66 lbs.

Thanks again as I charge the dremel battery
Richie

Richie, I've mentioned that modification on the 160 to a few folks, but I'm not sure anyone has taken an animal with the 'Mini El Grande' yet. Let me know if you do, and how it performs for you.

Td
TGMM Family of the Bow

I haven't broken any 75s yet (my arrow required 200 grains from bareshaft tuning)... I've taken down pigs (including a couple of real nice ones), a camel and a brumby. Some hits were pretty tough bone hits.

Ben,

We didn't get them on every shot either - but we did get them on about 10% of the heavy bone hits (I'd have to check to get the exact percentage). Like so many weak-points, they show up more on angular impacts. To me, one failure that I could have prevented is something that haunts me; it's one too many.

Ed
TGMM Family of the bow

It's the "snap off" tendency you're seeing that concerns me, that would essentially render the arrow immediately useless for the mission it started on.  I'd rather see them bend a little than break off like that.

I see some torture testing of my own in the very near future!    :scared:

I wonder if it is endemic to all the 75's or did you just get a bad batch?  Maybe someone who has had good luck could break one off at the junction and see if the thin metal issue is longterm or just one batch?

Doc:

I did some "highly scientific" research in the 75g steel adapters I have (from 3-R or KK - don't remember which).  Based on placing a wire into the bored out section, and then aligning it to the outside, the depth of the bore is to the last "grip ring" - 12mm.  This leaves approx 2mm of solid base.  My heads also do not have the reverse chamfer at the base where it would mate to the shaft.  Sorry, no pictures.

Could there be a "brand" problem?

Curious to others findings.

BobW

Further review of your photograqphs reveals that my adapter shafts also have a step down to the threaded section, and fewer "grip rings".  Wall section is also 2mm thick.  Appears to be a different product.

BobW

Interesting stuff.

LKH, that is exactly what I intend to do.

BobW, as far as I know all the steel adapters have been made by PDP but they certainly may have changed them a bit over the years.

Mike Walker, good point on the minor change at that spot.  I hadn't noticed it until you pointed it out.

The ones I have look like this (sorry for the poor photography)
(http://i104.photobucket.com/albums/m193/robertwestfall/DSCN3110.jpg)

I'm hoping that this is just a 'brand' problem. These particular tapers came from 3 Rivers, about 3 months ago. All of them have the same depth cavity inside the taper, and all have the correct 75 grain weight. If you're using 75 grain steel adaptors, it appears that it would be a very good idea to check them out.

Just playing around a few minutes ago, I mounted a 190 gr. field point on a new out-of-the-pack taper and screwed it into a shaft having a 100 grain brass insert. Holding about half-way up the shaft, a moderately sharp srtike against the metal workbench, at about a 30 degree angle, snapped the taper; just like all those that have broken in testing. I'll guarantee that strike was far less than it would have been from even a fairly light-draw bow.

Ed
TGMM Family of the Bow

I have some 75gr steel adapters from 3 Rivers that I bought in 06 and they are long tapered ones just a hair shorter than the 100gr ones. I stuck a screw down the hole and it came up quite short maybe a 1/16" from the bottom of the taper. I then did the same thing with the 100gr ones and the hole is drilled much deeper in them. My 75gr ones have deeper rings that go to a straight shaft. I wish I knew how to post a picture. I think they changed the design for cost reasons.

When I get back, I think I'll be checking ALL the new BH tapers I just resupplied with against the one's I've been using (my last 'resupply' was about 2 years ago). I hope there hasn't been some 'improvement' (design or materials) that merely improved the manufacturer's bottom line!

Ed
TGMM Family of the Bow

my adapters are from last summer and from KK.  Seem to be good stuff.

That will be interesting. I think all of the 75gr are short tapers now. Back when the only steel adapter was a 125gr I tried to drill out the inside and they broke just like yours did. I am going to keep the 75gr that I have for as long as I can. Thanks for the info Ed.

Ed,

On a parallel topic, is there a performance issue with the "short" steel tapers?

I had a little time to experiment with this tonight.  In was not able to break the adapter, the adapter held but enough force was applied that the broadhead ferrule split!  I am scratching my head trying to figure out why you're having such poor results Dr. Ed, others have had no trouble and I get something like this.   :knothead:   There does not seem to be consistency.  Visually I would say this adapter is a match to yours Ed, it appeared to me to be same manufacture.  Here's a pic of what I got:

 (http://i106.photobucket.com/albums/m276/BraveheartArchery/75adapter.jpg)


Hardly scientific I know but it's got me scratching my head.   :help:   I did check the depth of the hollowing out and it also seemed very shallow.  I checked a 100 in comparison and I'd estimate the 100 had 4 times the steel down at the base, compared to the 75.

Could it be that the Grizzly's have a thicker ferrule of steel compared to the one your using and the 75 gr adaptor is the weak link.

What I may do is take the 100 grain adapters and apply them to the grinder until they're 75 grains, might take a few minutes but it they dont break....who cares?

I'll just take some off the tip...

Jason, I don't know on that, the ferrule walls on the 190 Grizzly would certainly be thicker than the head above though so that could be a possibility.

Russ, that's a great idea.   :thumbsup:   Let us know how it turns out.

Tim,

Now you have me wondering if this batch is just faulty, but the thin metal holding the shank to the taper also just looks far too thin to hold up well (shown in the first photo). I've not had any of the broadheads damaged on the shots where the adaptor gave way; yes, all 190 Grizzly.

Here are all the numbers off the packages I have (if need be, I can take a photo of the pachet and post it). First numbers; C-01-B-23, then under the bar code is 4226-2. Can you match that up to the adaptors you have?

I retried the sharp-rap test on the workbench ... and there goes another adaptor. I tried to see if I could snap one off with just hand pressure, but it held up to that.

This is perplexing and troubling. If it's a temporing or fabrication problem, where was quality control? Each of theses 75 gr. adaptors I have seems to have this problem.

This has open my eyes to something I was beginning to take for granted. I've always used 125 gr. adaptors; they are all I'll use on my hunting arrows; and with no problem, but I think I'm going to start destruction testing a couple of saples from each lot of adaptors I buy, regardless of the weight - in essence, doing my own double-check quality control. The less left to chance, the better.

Let me know if you can match these numbers up to a manufacturing lot, or something of that nature. They may just be for stock control.

Ed
TGMM Family of the Bow

Dr.Ed, thanks for the lot number information.  I will check mine against those for sure but will not be able to do so until later today.  If it is a batch problem maybe that accounts for the inconsistent results?  I believe only the manufacture probably knows what all the numbers mean, but I certainly should be able to tell if my lot matches yours or not.  I do know that my rough measurements of the depth of the 100 vs. the 75 would suggest finding a way to accommodate the extra 25 grains at least would be worth the trouble.  About 4 times thicker at the breaking point than the 75 from what I can tell.  Russ' idea of grinding down the 100 may be the ticket if a shorter or lighter adapter is needed, although so far the one's I've got seem okay.

My guess would be the 4226-2, means they were made the 226th day of 2004, 2nd shift.  Its a typical manufacturing "Julian Date".  Makes tracing the product much easier.  That is, assuming I'm right.    :scared:

Java Man,  
That is not the manufacture date.  4226-2 is 3R's part number for the computer system and catalog the other number is the warehouse bin location number.  It has nothing to do with who, when, or how they were manufactured.  These things on the internet spiral out of control sometimes.

Dr. Ashby, have you contacted either Danny or Dale at 3R.  There is a lot of speculation going on here that maybe they could answer and if there is an issue maybe they need to know about it.  Just seems like the logical starting point if I had a problem with a product or noticed a flaw. dino

Has not happened since but about a year ago I had three 100gr adapters (from the same doz. pack) break the same way and had seen on the LW that someone else had the same problem with their 100gr,ers as well, at about the same time! I Think it was a steal issue.

Dean, I started this thread out merely to alert others, amd see if they had noticed the problem. These are the first 75 gr. adaptors I've done any testing with (and the 100 gr. ones too, for that matter). Wasn't sure if this was an isolated problem or a generalized problem. I think just emailing this thread to 3 rivers might give them an all-round heads up to what may be a problem.

Ed
TGMM Family of the Bow

Dean,

Thanks for the correction.  

Gregg

Dr. Ed, all the lot numbers we have here at Braveheart are similar but they do not match yours.     :confused:

One does not mean much but I recently had a 100 grain adapter fail as you describe.

I've had aluminum ones break before but never a steel one.  I've only used the 100 grain steel.

Arrow Axis ST 400 w/ 100 grain brass insert.  Steel 100 grain broadhead adapter with 135 grain glue on judo.  

It took quite a bit of abuse stump shooting around the yard.  

That is until I slapped it against my foot to knock off some dirt.  The judo went flying to lands unknown leaving the threaded shaft of the adapter still screwed into my brass insert.

i spoke with one of the reps for 3rivers yesterday, and we talked about the issue he was not concerned with the test results he claimed as far as they knew the 75 grains were not issue.and he had not heard of any complaints. he seems to think that" mr ashby test are a torture and are fine for whitetail and elk" just passing on the conversation

Interesting, since all the test shot failures happened on the bones of Georgia whitetails. Anything more than a whitetail rib becomes a torture test? Makes me wonder ...

Ed
TGMM Family of the Bow

i did some testing on my own today after using some of the 75 grain adapters, and glueing them to a magnus 2 blade broadhead, and shooting a carbon express arrow out of a striker stinger longbow 50#at 28inches. at aprox 10 yds i shot the attached broadhead/adapter into a sheet of drywall,5 times with no damage on the broadhead or adapters, then the same combo was shot into a 3/4 of pine 2 times with no damage to the broadhead but most importanly the adapter, i only stoped shooting because i didn't want to dig them out of the wood anymore.   (http://i138.photobucket.com/albums/q271/flightmedic_album/P3090127.jpg)

Steve, do those you're using appear to be the same as the ones I have; show in the photos? Is their cavity the same depth? If so, it's hard to account for the vast difference in performance, unless in the tempering. The ones I have will snap with what feels to be far less lateral pressure than it takes for me to bend a (solid, not hollow) aluminum adaptor. Did you try any angular impacts?

I did email this thread to the folks at 3 Rivers, but there has been no reply.

I'm really interested in finding out the what and why of the failures we've had (it's happened for Wesley, Dennis and I). I'm also interested in the seemingly vast differences in construction shown and described by the folks posting here; between the adaptors they have and those we have. If one version is out-performing the other, it would be good to know which is which, and by whom they are manufactured.

Ed
TGMM Family of the Bow

Ed,

The picture Mike Walker posted (page #2), and my head are the same model - these are "short" 75g steel.  Mine came from KustomKing.  They match the image in their on-line catalog.

BobW

Dr. Ashby, it sounds like 3 rivers is going to give you the "ignore till he shuts up treatment".   The last thing they want to do is admit their product may be faulty.

You need to restart this thread from time to time, not just recycle this one.  That will keep it current and I know I won't be buying any inserts or adapters till they answer.

Thanks Bob. Those Mike show have a significantly different shank profile that those I have, and it sounds as if they have a lot more metal thickness at the base of the taper's counter-bore.

I was trying the 75 grain adaptors out because I want to set up a lower mass Extreme FOC arrow for some testing from a 43# bow this year. I have some higher mass Extreme FOC's already set up for it, but also wanted to test some closer to threshold mass, but still with good structural integrity. Was planning on using the Modified Grizzly on the 75 grain adaptors, and a low mass/inch shaft. However, the ones I have certainly are not going to work.

Think I'll experiment with some like those Mike and you are using. It will save me having to shorten the 100 grain models. Got enough to do without that!

Ed
TGMM Family of the Bow

Larry,

I don't think these adaptors are necessarily a '3 Rivers brand'. They probably just buy them from some manufacturer and re-package them. They can't proof-test every product they carry. However, I hope they are concerned enough about their customers (and the animals they hunt) to investigate this potential problem product. I'm hoping that's what is taking them so long to reply; they're checking it out.

I lean towards this being an inherent design flaw with this particular adaptor; the counter-bored hole in the taper just doesn't leave enough metal thickness at the shank's attachment.

I don't have all my measuring equipment here, but think I can locate some to borrow. I'll do some precise measurements to post. Back in a bit.

Ed
TGMM Family of the Bow

interesting iv never had a problem with the 75gr adapters before and i use them on all my arrows to get 200grs up front with 125gr BH.
i will do some testing and measuring here and see what i come up with.

interestingly when i shot my 2 Water buffalo ( and did some testing with shoulder hits with both my recurve and compound) i had 4 of my 100gr brass inserts brake or bend, i was using the 125gr steel adapters, 1 of which also broke just in front of the thread. iv never used the brass inserts again for that reason.

i will look around and see if i have some of the damaged inserts(think i threw them away) and pics of the shots that may be of some use to you Ed

Thanks Andy, I would really appreciate that. Arrow integrity is so critical. I'm hoping that the Internal Footings will provide a significant boost in carbon shaft durability. First pre-production prototypes will get a workout this year. They're a different material than the IF's I developed and tested, for manufacturing reasons, but are also a 'single-unit', where mine were not. That is a big plus. Time will tell if and how well they work.

*****************
MEASUREMENTS
*****************
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 # 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 - antually 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

The "KustomKing" heads have 2mm (possibly 2.5) of material between the tip if the bore and the interface that butts to the shaft.

BobW

Bob,

For perspective: 2mm = 0.079". That's almost 8 times the metal thickness attachment of the adaptors I have here. 2.5mm = 0.098", or almost ten times greater. Big difference.  Think I still far prefer the heavier, solid adaptors.

I wish someone out there would consider making the lighter weight adaptors from something like titanium; lighter than steel, but stronger than steel.

Ed
TGMM Family of the Bow

sorry for bein slightly off topic.

well i found some of the old Buffalo arrows with the broken 100gr brass inserts. The two i have are both broken in the same place, just where the brass wall steps thinner to accept the thicker tang of the adapter above the thread, you will see both the adapters are broken here too      

The first pic shows both arrows with the broken brass inserts and back of adapters still inside the arrows.    (http://i62.photobucket.com/albums/h101/tradtusker/IMG_2326.jpg)

the second pic is the broken brass insert with the thread from the adapter still in it once i removed it from the arrow, with a good brass insert next to it for reference.
 (http://i62.photobucket.com/albums/h101/tradtusker/IMG_2333.jpg)

the last pic shows where they all seemed to brake and bend in relation the the adapter and insert.

 (http://i62.photobucket.com/albums/h101/tradtusker/IMG_2335.jpg)

hope it of some help to someone, i was not impressed by how many broke like this.
not everyone on is gonna be hunting buff with heavy gear,  but i'l try not to use them.

Ed have you ever seen this in your testing?

Just tested the 75gr adapters out of interest and they broke!and like Ed measured its a tiny amount of steel holding it on.
iv use them lots for hunting but this is a big design flaw, gonna be changing to 125gr adapters.

(http://i62.photobucket.com/albums/h101/tradtusker/IMG_2343.jpg)

(http://i62.photobucket.com/albums/h101/tradtusker/IMG_2342.jpg)

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

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

Thanks Andy. Very much looking forward to getting them.

Ed
TGMM Family of the Bow

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

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

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.

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:

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"

   :(

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.

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

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

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

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.

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

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

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

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

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.

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.

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.

don't sacrifice an arrow mate go to the first page page of this post :  http://tradgang.com/noncgi/ultimatebb.php?...=1;t=066501;p=2  

the hammer test spoke already .....

:bigsmyl:

i shot a small doe in sept. and had the same results the insert broke at the same spot.i thought it was a fluke til now as i have not had a cjance to break another one on anymore deer.