Tac15i accuracy and consistancy problems

Hey shooter981,
I know exactly what you are going through. I just sent a message to xbow755 earlier today asking him if he had this issue, and how he dealt with it if he did have that problem. To start with, I paper tuned the bow with an arrow with no fletching until I was getting bullet holes. I only used 1 arrow over and over to acomplish this. I then proceeded to install my scope on my HHA Optimizer. I knew from reading the posts on the forums that the scope would have to be shimmed in the front in order to have the cross hairs be zeroed at 20 yards. The shim IMHO is needed whether you use an Optimizer, or just a scope on the rail. This will allowyou to set the elevation, and windage on your scope to the mid point in both directions to start your zero in at 20 yards. ( I learned from trial and error when I first purchased the xbow that when trying to lower my scope to zero in at 20yds the windage became very limited in adjustment.) I am very particular to crank the bow back just barely enough to have the release sled fall into the slots. I have also insured that the cranking string knot was sitting flush in the cranking drum. This prevents string jump and ensures a level wind keeping equal pressure on the cranking sled.I have been setting up my targets at many distances to plot out a sight tape for my Optimizer, and I notice the same thing as you are referring to. I will have 4, 5, 6, even 8 arrows fly good, then I will have a few flyers. I am using 3 arrows to sight in with. The thinking is that you use only one arrow to ensure repeatability, but I have a hard time believing that all 3 arrows will fly so perfect then all 3 arrows will fly off my mark by 3 or 4 inches at 50 or 60 yards. I am shooting off a very good gun rest (tripod and sand bags) with no wind while sighting in. The table I am using is made out of heavy galvanized steel which does not move. I have yet to figure it out, and it is making me very nervous to hunt with this bow when there is a possibility that the arrow will be a flyer. The only thing I have not done is index my arrows. But like I said the 3 arrows will fly perfect then at a random time fly way off mark. Maybe someone has had this happen and knows what to do.

 

Based on a similar "shift again" exasperating <insert bad language here> experience with a well-known, big-buck brand of rifle scope on a deer rifle, I would definitely would try a different scope.

Thinking positively: Even if swapping the scope does not solve the problem, you will have made progress towards resolving your problem, since you can now eliminate the scope as the cause.

Oh, and don't make the mistake I made. Swap the current scope with a different brand scope you know is rock-solid. My mistake was swapping the scope out with the manufacture's replacement, which failed in the same exact manner after about 20 rounds.

Please, let us know what you find.

 

I was having similar problem with my setup two weeks ago (Right before one of the limbs started separating) I would shoot about 6 arrows and some would be grouped in one spot and the rest about 6" lower. (both groups would be about 1" at 40yards). My initial thought (and is still my #1 guess is the scope), I do not think it is that high a quality of scope to begin with (Based on the problems I had with the battery compartment) When I get the xbow back from the shop and I re-tuned/sighted it in I will have to test again and hopefully it goes away, but I'm not counting on it.

WildWillie

 

I had the same issue the 1st time a limb split. I tried everything I could think of; scope first, pron square with rail, cam level and clearance, string mark alignment, bow/scope level, biscuit and D-loop alignment. Just couldn't set the scope because shot placement was inconsistent (4 to 6 inches off in random directions).

Check your limbs very carefully for spintering or "hangnails", use your "best" arrow for tuning (and hope it doesn't swallow the nock before you've finished).
GOOD LUCK!

 

please let us know what the out come of this is because i am planning on buying one this winter after Jan. and i had it down to two x bows the tac 15 or the Excalibur and i know that the Excalibur is a great x bow

 

You may already be doing this with the Arrows, but we need to be sure we are on the same page. Are the arrows Literally Numbered as "#1", "#2", ... "#13", "#14" ?

Thus when you say:
--- 7th arrow went 2" left, does arrow #7 always go 2" left?
--- 12th arrow went 8" low, does arrow #12 always go 8" low?
--- 13th & 14th arrow went 4" low, does arrow #13 & #14 always go 4" low?
And arrows #1, #2, #3, #4, #5, #6, #8, #9, #10, #11 all hit in the same place.

If your arrows are not numbered, then number them and shoot them** in order, noting where each arrow hits. Repeat the process. If you start to see a pattern, arrow #7 always hits 2" left, while arrows #1-#6 always hit in the same place, then you know the problem is related to the arrows.

And yes, it is quite possible for you to have four arrows out of fourteen arrows that hit different than all others. Frankly, if you have ten arrows out of fourteen arrows that hit in the same hole at say 50-yards, consider yourself very lucky.

** One other thing, make absolutely sure, you load each arrow every time with the same side facing up. Some of us have found our arrows have a strong side and weak side. Thus, if you shoot the arrow with the weak side up it will fly one-way, and when loaded with strong side up it will fly another-way.

There is one other way to go about this. Shoot the same arrow, loaded with the same side-up twenty times. The arrow should hit in the same place almost every time. If the arrow hits in different places 2" left, 4" high, 8" low, ..., then something about how the X-bow is being held/shot or the X-bow itself has a flaky problem.

 

Shooter981 -

A few questions :

1 - When you say you have a noticable crack when drawing the bowstring in the same place, it sounds like the problem I was having. For me it turned out to be the string was winding around one part of the spool when cranking and would eventually slip to another part giving a crack sound but also dislodging the arrow from the string.

2 - When you were doing your shooting were you using only 1 arrow and shot it 14 times or did you shoot 14 different arrows ? At 1st I thought you only shot 1 arrow, but then it sounded like you were shooting different arrows.

Also from years of High power rifle shooting, are you getting the same spot weld to the stock when you sight through the scope ? What I mean by that, are you always positioning your cheek the same way from shot to shot on the stock ? If you change your head position it can change your point of impact (Althought it should not at close distances, but just checking )

I'm still without my Tac and will probably be another week before I see it.


WildWillie

 

Just verifying. Is the "crack" happening as the TAC-15 is being cocked (cranked back)?

Let me say this in advance. My TAC-15i does not make any "crack" sounds as it is being cocked. Occasionally, there is a "Pop" sound, which comes from the cocking-string popping between string-loops already wound over the crank's internal shaft.

Now, when my TAC-15i is shot, there is a "crack" like sound ("thump"?) as the limbs are suddenly stopped by the string hitting the rubber bumper stops.

 

For what it's worth, the noise you have described and the loss of accuracy is reminiscent of what I have experienced. I discounted the noise at first , thinking the cams were binding. The dealer's response was to use a fine oiler and lube the shaft pin area. It wasn't until the bow misfired that I shipped the unit back to the manufacturer. In both cases, the limbs were replaced. The first time, I never saw any cracks; it wasn't until the factory disassembled the unit that the cracks were found.
Most recently, just prior to the noise starting up again, the bow was hitting tacs at 40 yards. Then it started again: a few good shots, then a flyer. The limb was delaminating and splintering.
The good news is the bow's back together again and preliminary sight in has been achieved.

 

I wonder if the cracking (delamination) of the limbs would show up on a X-ray?

Anybody with a TAC-15 with cracking limbs know a Doctor or Vet that could X-ray a cracked Limb, then the replacement limbs to see if one could tell the difference (see hidden damage)?

The one Vet I know who has an all Electronic (no-film) X-Ray system, the X-Ray detector is way too small to use. It is meant strictly for looking at teeth or small bones vs. abdomen or leg bones.