Lose the Biscuit and Improve Your TAC15/15I Shooting Performance - By Russell Beach

Andy Backus

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Buy the Drop Away Style Arrow Rest right here at the LRH Store.

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Provided to LRH by Russell Beach.

I decided to write this article to help all those PSE TAC owners who were either having consistency problems or who just wanted to upgrade their crossbows to a better performing, more consistent type of arrow rest. In doing so, I decided to break this article into two halves; the first half will explain the benefits of changing to a Drop Away Style Arrow Rest and the second half provides the Step-by-Step instructions with photographs to walk you through making the conversion. There is a third part to this conversion process which is optional that will also add a tremendous amount of versatility to your crossbows capabilities. This deals with the modification of your crossbows Weaver Style Rail (Scope Rail), that permits you to use standard three fletch arrows, so you are no longer locked into shooting only PSE TAC15 four fletch arrows. This option will be discussed in an add-on article that will follow these instructions at a later time.

Ok, so let's open with exploring the obvious questions which are: "Why should I consider changing my current Whisker Biscuit Arrow Rest, which is fairly new and in good shape? What makes the QAD Ultra Rest Pro HDX Drop Away Rest any better than my current rest?

The stock manufacturers choice of using the "Whisker Biscuit" style arrow rest had more to do with the crossbows initial intended tactical use and far less to do with accuracy or performance. The crossbows ability to be loaded in complete darkness with total simplicity for military tactical needs was a major driving force in its design and selection of this type of rest. I'm sure as a PSE TAC15/15i owner you're already aware of the wear factor on the bristles of your Whisker Biscuit Rest. Any wear at all will undoubtedly change your scopes elevation point of impact at all shooting distances. As you increase your shot distance these variations become magnified, so this means that your site settings will need to be modified more frequently as you shoot more, due to the wear and tear factor on the bristles of the rest. If this was your only concern I might be able to live with it, but there's much more going on that you're probably also not aware of, so let's talk about the other major issues that are affecting your shooting accuracy with this type of an arrow rest.

In the world of archery we have something known as the "Archers Paradox". This deals with the dynamics and effects of g-forces on the shaft of an arrow when launched from a bow or crossbow. These extreme forces are produced when the pull weight of a bowstring or cable are released against the weight of an arrows point. The resulting forces cause an extreme series of bends or flexes in an arrow shaft as it abruptly moves forward, such that when viewed in slow motion an arrow shaft can often bend in its center well outside the range of a typical arrow rest. I strongly recommend that you Google the term "Archer's Paradox" so you can understand more about this topic.

The key point being that with all the violent flexing back and forth, do you really believe the friction from all these bristles can remain consistent and not interfere with the uniform flexing of your arrows shaft each time you release the cable during a shot? Well, if you do, you need a significant amount of engineering schooling to get you up to speed with the technology.

It's extremely likely that every few shots your Whisker Biscuit is going to apply a different amount of pressure to your arrow shaft as it attempts to launch an arrow through those bristles. As I've stated in writing numerous times, you have something called the "Archer's Paradox" taking place and with all the violent flexing back and forth, how would you expect the friction from all those bristles to remain consistent? In order to achieve some level of consistency you would need to have first aligned your arrows stiff part of the spine with the indexing of your arrow nocks to insure they were all flexing in the exact same direction. This would require a Carbon Spine Tester and removal of the nocks from all your arrows, then alignment of the arrow spines to the position of each nock so that the stiff point of each arrow aligns in the exact position with each nock. Even doing this will not totally prevent the inconsistencies associated with the bristles of the Whisker Biscuit during shooting.

The common problem of not being able to get your arrows to group well consistently is a result of two basic factors after initial set up and tuning. It is either caused because your arrow shafts are not properly sorted, spine marked and nock indexed or you are having rest interference issues when shooting. Often it can be a combination of both of these issues and since we have already documented how to sort, spine test and index your arrows in previous articles, we are covering the arrow rest replacement in this article.

We could argue that it's because all my spines have been perfectly matched and all my arrows spines are indexed exactly the same to my nocks, that since changing my arrow rest for a drop away I no longer have any inconsistencies or occasional fliers, but I'm willing to bet that getting rid of the arrow flexing restrictions and friction caused by the Whisker Biscuit rest you're using will go a long way to correcting these problems also. If I didn't think so, I wouldn't have changed my own rest out and I wouldn't be recommending it to others.

Your crossbows "front end" is very limited as to what can cause these types of problems? I'm not a believer in the limbs being a culprit in all but the most extreme circumstances, possibly one in a couple thousand cases. The biscuit however is an entirely different story. I believe it can account for the majority of these types of deviations in arrow flight performance on a very regular basis. In any archery shooting situation regardless if it's a crossbow or a standard compound bow, this is always considered the likely culprit. You don't need to take my word for it, you can speak with any good archery pro or a good pro shop and get the exact same information.

Knowing this was a historical problem and its potential impact was exactly the reason I dumped the "Whisker Biscuit" type arrow rest as soon as a good Drop Away replacement became available. The logic is simple; if a rest isn't there it can't be in the way or interfere and cause problems during launch. Your arrows then have the ability to flex naturally and therefore fly the way they were designed to fly according to their specific spine designations. The Whisker Biscuit type arrow rests attempt to contain and alter the spine properties and limit the shafts dynamic flexing properties. In simple terms for you novices, this is all bad and should not be taking place.

Another key benefit of the QAD Ultra Rest Pro HDX Drop Away Rest is the fact that there's nothing to wear or change. Therefore once you have it set-up and tuned you need not worry about changing your site settings do to wear and tear. Your settings will remain the same year after year unless you change something on your crossbow, but there are no bristles to wear down or to be replaced.

Once you change out the arrow rest you can also modify your crossbows Weaver Rail so you don't need to shoot 4 vane arrow configurations. You can shoot standard three vane arrows and achieve tighter groups and no more vanes rubbing anything. With the new higher quality arrow shafts by other manufacturers which have hit the market, it allows one to easily change to these far superior offerings.

I could easily list another several reasons why all shooters will easily benefit from dumping their current Whisker Biscuit Style Rest and making the switch, but I think I've probably gave you enough reasons at this point to more than justify the logic, so let's move into how you can accomplish the conversion. The step by steps below were created and produced by a gentleman from Alabama by the name of Russell Beach and Russ has produced an outstanding set of instructions that make the conversion as easy as possible, so read the instructions below carefully and pay attention to the pictures that go along with the verbiage.

If you're hunting, I do not recommend changing anything at the moment because no matter what you touch it's going to change the way your crossbow is shooting and this will affect your current accuracy until to have it adjusted and tuned properly.

Wait until you are done with the hunting season and then make your customizations, so you have time to work on it without it affecting your hunting capabilities.



Fact! I received an immense amount of help and advice from xbow755 and information from Super 91 for completing this modification. Thanks fellows!

Following is an outline of the steps and some photos to illustrate the installation of a QAD Ultra Rest Pro HDX Drop Away Rest and Bracket on my TAC 15. Installation on anyone's TAC 15 or TAC 15i should be pretty much the same.


  • Remove the old Whisker Biscuit and retain the 2 screws used to hold it to the riser (PSE nomenclature is Prod); you will need these screws to attach the QAD Rest Bracket.
  • I found it easier to attach the QAD Rest to the Bracket before attaching the Bracket to the riser (my fingers are too fat and stiff for small spaces). Directions for assembly of the QAD Rest to the Bracket will come with your Bracket. Snug screws for now.

Note: I had to use a spacer between the Bracket and riser to ensure the Bracket cleared the curve of the riser (see photo below looking down on bow). You shouldn't have to use a spacer for your installation as the current supply of brackets has the spacer built in. The Launcher is rotated to the 80 degree Capture Position in the photo (no felt is installed on Launcher in this photo). Note the Timing Cord going down through the Collar.


image001.jpg




  • I initially centered the vertical and horizontal rest adjustments (instructions for these adjustments come with the QAD Rest) and then mounted the Bracket, with the rest attached, so that the bottom of the vee in the Launcher was centered on the riser and barrel channel and level with the nock point string loop on the bow string. See photo below. If you look closely under the middle level, you can see the nock point on the string lying against the Anti-Dry Fire Catch near the center of the bottom of the Launcher vee. Don't laugh too hard at all the levels I used; this is simply my method of keeping everything aligned and level with the barrel and riser (prod). The yellow level is sitting on the limbs, the black level is sitting on the riser and the one in my hand is against the bottom flat of the Bracket. Limbs and riser are level with the Barrel. The photo is canted slightly because I didn't hold the camera level, but the bubbles are all centered. Paying attention to alignment and leveling will pay off when shooting longer distances. Tighten the screws, but be prepared to loosen and readjust the bracket during final adjustment of the rest.
image003.jpg

Timing Cord attachment was my next step and is different than the instructions included with the QAD Rest.


  • You will need to locate a point on the cable that goes around the cam on the right side of the bow (do not use the cable with the yoke that goes to the axle posts). This point is the attachment point for the Timing Cable for the Launcher. (This point would be on the downward traveling buss cable on a vertical bow.) Locate this point 1/8 inch to ¼ inch from the string stopper rod. I used white out to mark the point on the cable which can be seen in the photo below. This photo was taken from below the bow (looking front to rear) with the string in the full draw position to illustrate how close the point marked on the cable comes to the cable groove in the cam. Use extreme caution and keep the safety on and no arrow nocked when in the full draw position!
image005.jpg


  • The Timing Cord should be attached to this cable before it is threaded through the hole in the Collar on the Launcher shaft (the Collar comes with the Bracket). This is sort of opposite the installation instructions included with the QAD Rest for attaching the timing cable to a vertical bow. The cable clamp that comes with the rest won't clear the cam so the Timing Cord can be served to the cable with serving thread or attached with a string loop knot or your method of choice. I used about 1/3 full draw for space while serving the Timing Cord to the Cable. However the Timing Cord is attached to the cable, it must clear the string stopper rod, the cam and must not slip. See the three photos below.
  • The first photo below is the top view of my attachment; the second photo is the bottom view. The bow string is against the string stoppers in the first and second photos.
  • The third photo (taken from directly below the cam) shows how close the timing cable attachment comes to the cam in the full draw position. (Use extreme caution when in the full draw position and always keep the safety on!)
image007.jpg

image009.jpg

image011.jpg
 
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Lose the Biscuit and Improve Your TAC15/15I Shooting Performance - Part 2

  • With the bow in the full draw position, safety on, thread the Timing Cord under the riser and through the Collar that comes with the Bracket so that it comes out of the hole for the Cord Lock Screw. Look at the first photo for the hole where the Timing Cord goes into the Collar. Rotate the Launcher to the Full Draw (90 degree) Position, tighten the Timing Cord so the Launcher is held in the 90 degree position and then tighten the Cord Lock Screw on the front of the Collar. See photo below taken from underneath the riser.
image013.jpg
  • The photo below is a low frontal view of the Launcher in the Capture (80 degree) position after adjusting and tightening the Timing Cord Lock Screw at full draw and then letting the bow string down to the String Stoppers. You can see the Timing Cord exiting the hole with the Cord Lock Screw.

Note! The Collar replaces the Thumb Wheel that comes mounted on the Launcher shaft. Directions with the Bracket will tell you to remove the Thumb Wheel and retain the Cord Lock Screw for use with the new Collar.

  • I coiled the extra length of Timing Cord and will trim and burn the end of it after final adjustment of the QAD rest.
image015.jpg
  • The next photo is also a low frontal view showing the Launcher in the Drop Away Position (0 degrees). You can see the entry hole for the Timing Cord where the Timing cord wraps around the Collar
image017.jpg
  • After final a check and tightening of all screws, you should be ready to paper tune and complete final adjustment of your QAD Ultra Rest Pro HDX Drop Away Rest.

  • Paper tuning and final adjustments I will leave to each individual archer as most of us have our own method of doing certain things. Good luck and good shooting.

This article was written by Russell Beach (rmbeach)

To purchase the QAD Ultrarest HDX and Custom TAC 15/15i Mounting Bracket by Archery Unlimited, Inc. at the LRH Online Store - CLICK HERE
 
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Re: Lose the Biscuit and Improve Your TAC15/15I Shooting Performance - By Russell Bea

Can you clarify something on the "QAD Ultra Rest Pro HDX" mounting bracket used on the TAC-15?
In the pictures the bracket looks to be turned 90-degrees from sales pictures of the "QAD Ultra Rest Pro HDX".

Is the bracket custom or is the bracket capable being turned & mounted 90-degrees to the rest?
 
Re: Lose the Biscuit and Improve Your TAC15/15I Shooting Performance - By Russell Bea

OkieBowie, sorry for the slow response......I'm spending too much time in the woods!

To answer your question, yes the bracket is custom. It is actually a section of aluminum angle with holes drilled in one leg to fit the holes used to mount the Wisker Biscuit to the Tac 15/15i riser. The other leg is machined with a slot to fit the body of the "Qad Ultra Rest Pro HDX". The Mounting Block and Thumb Wheel that comes with the rest are not used. The Bracket replaces the Mounting Block you would use for mounting the rest to a vertical bow and a Round Collar replaces the Thumb Wheel. The Draw Cord is threaded through the Collar.

If you look at the first photo from above the bow you can see the angle (machined to fit the curve of the riser) has both a slot (for the rest) and a tongue (that fits into the rest).

A simpler way to put it is the Qad Rest is mounted in line with the riser on a vertical bow and we are mounting it perpendicular to the riser on the TAC 15/15i which is why the section of angle is required.

If you need more info, I'll take some more close up photos.

Regards,

rmbeach
 
Re: Lose the Biscuit and Improve Your TAC15/15I Shooting Performance - By Russell Bea

... yes the bracket is custom. It is actually a section of aluminum angle with holes drilled in one leg to fit ...
Okay. As much as I love using my die-grinder and bits to mill with...:rolleyes: I already have a full plate of "To Dos" and "Past Dos".

Is a company (or person) making (cad/cam-ing) the brackets that we (me) can perhaps buy the brackets from?
 
Re: Lose the Biscuit and Improve Your TAC15/15I Shooting Performance - By Russell Bea

OkieBowie, PM sent.

Regards,

rmbeach
 
Re: Lose the Biscuit and Improve Your TAC15/15I Shooting Performance - By Russell Bea

Hi Russell,
Congratulations and specials thanks for getting this article done and published for everyone interested in improving their TAC 15/15i accuracy and performance.

After careful review and reading if your article I think this is one of the most well put together articles outlining a series of step-by-step activities on the TAC 15's I've read to date.

Clearly, a great deal of time and effort went into this piece of work and many of our members and readers will benefit from having this article as a reference.

Regards,

Jon
 
Re: Lose the Biscuit and Improve Your TAC15/15I Shooting Performance - By Russell Bea

Thanks Jon, I had a lot of help and input from several excellent sources!

rmbeach
 
Re: Lose the Biscuit and Improve Your TAC15/15I Shooting Performance - By Russell Bea

Hi Russ,
The sources supply little bits of helpful information, but this one is all you!

Regards,

Jon
 
Re: Lose the Biscuit and Improve Your TAC15/15I Shooting Performance - By Russell Bea

i have a drop away rest on my tac but need a better working version, presently i am using an old mechanical drop... no strings, its fantastic when it works but too unreliable it drops with the slightest bump.. that is the trouble, i wasnt too sure a string would work but now i see it will, tomorrow i am going for a rest, the bracket i can make with no problem, after i make the first and prove it out i could possibly make more for the ones that dont have the time or tools, within a few days i will have a bracket done, i will update with more when complete, hunting might get in the way as its mid season for me here and still chasing the monster on the property.
 
Re: Lose the Biscuit and Improve Your TAC15/15I Shooting Performance - By Russell Bea

Hi sangerboats,
The drop away rests that are already being produced, such as the QAD Drop Away Rest Brackets have all been modified numerous times since their inception.

The key is getting the rest properly positioned in the bracket so that the rest is exactly centered to the crossbows center shot alignment, both vertically and horizontally.

Also, the better rests insure the arrow holder stays down and out of the way after the release of the shot. This eliminates timing concerns with the arrow holder bouncing back up into the arrow shaft before the arrow can clear the crossbow.

The only addition I would like to see added to the current QAD Bracket for the TAC15 / 15i are some etched scales where the hex bolts lock the bracket to the front of the crossbows stock and between the two halves of the bracket itself.

Regards,


Jon
 
Re: Lose the Biscuit and Improve Your TAC15/15I Shooting Performance - By Russell Bea

I would like to see bigger heads on the hex bolts that hold the rest to the front of the bow. I added washers to mine but they are not much larger than the bolt head.

Other than that, I really like how this rest worked for me.
 
Re: Lose the Biscuit and Improve Your TAC15/15I Shooting Performance - By Russell Bea

I would like to see bigger heads on the hex bolts that hold the rest to the front of the bow. I added washers to mine but they are not much larger than the bolt head.QUOTE]

Thegunt,
If you look at the low front view photos, you will see I used small lock washers and large flat washers to attach the bracket to the front of the riser. I have not had anything come loose after two hundred or so shots.

Good luck with the monster!

sangerboats,
Like jon.henry755 suggests, use a drop away rest that has no bounce or you will have problems.


jon.henry755,
The addition of etched scales would be great when remounting the bracket or the rest!

rmbeach
 
Re: Lose the Biscuit and Improve Your TAC15/15I Shooting Performance - By Russell Bea

yes jon i already know it has to be centered, i used an old mechanical drop away with no cords attached to strings, the problem i have is the rest falls away at the slightest bump and its as tight as it can be and still work, with the rest i have on the bow i am shooting groups 2"or less at 160 yrds, it gets out of the way fast enough and stays down, it just isnt reliable enough.

i am in the process of making the bracket for the QAD and since i have machined the bracket for the rest i have it wont be hard to make one for the new rest, i will keep the suggestions in mind but feel it is not necessary for any roughing around holes as i do my homework and when complete the bracket does not need to move so hole clearance is nil... the rest itself has the adjustments, its going to be a day or so but will have pics soon, if anyone is needing a bracket for the QAD please let me know and i will finish a couple to help some fellow shooters get that biscut off this fine crossbow, i have a rest on loan for mock up to do the machining, i am in the design stage right now and will get working on the bracket by friday..

keep me posted with your comments

anyone on here from michigan? fenton-holly-flint area?
 
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