Hi Paul,
Wouldn't you think that the manufacturer of any given crossbow or weapon should be obligated to provide basic set-up and tuning documentation?
I hate to complain, but considering the cost of these xbows, they really should have included a lot more documentation to help their customers.
I'm not in the business of trying to make money. A few years ago when my writing and documentation on the TAC's began it was for the sole purpose of trying to help others who didn't have the level of knowledge or experience as do I. I tried to do this without costing anybody any extra money and at the same time to work within my allowable spare time. I'll be the first to admit the time invested got out of hand as more and more people began e-mailing me for help and the calls were becoming a nightly event. This falls under the category of "No Good Deed Ever Goes Unpunished"!
This has been somewhat a labor of love and doesn't apply to just me by a long shot. I had some very good company along the way in other members both past and present. To produce a manual would probably have been a sizable task and considering these crossbows have a limited life span before they are either replaced or modified which would likely change the quality of the information I've tried to keep up with them in the form of these forums.
Let's get to your current question / problem. The only major mistake you've made is that you made adjustments on your arrow rest and scope to compensate for shooting high at 20 yards.
This is a major No, No. Go back and set your scopes elevation adjustments to the mid point of the elevation adjustment in clicks. Also get a paper tuner and re-adjust your arrow rest bracket until you have a perfect bullet hole pattern at 15 yards. Once you have a perfect hole, lock off the arrow rest and forget about it. Never touch it again unless replacing the rest.
Next, get the adjustable scope rings made by Burris (Zee Rings) and follow the instructions that have been outlined by Buzzard Bait and others for proper shimming of your scope. The concept is this: Once your crossbow is shooting a perfect hole when paper tuning at 15 yards, this confirms the alignment between your arrow rest and nocking point is good-to-go. Next you now need to insure your scope is pointing to the exact same spot your crossbow is shooting. This is done strictly through the scope alignment process and the Zee Rings are the best possible solution to make adjusting this alignment easy and permanent.
Once the Zee Rings get you extremely close to being on the bullseye of your target at 20 yards you can then make any tiny tweaks using the the scopes windage or elevation adjustments, but these should be only a last resort.
Last, Now move out to 50 or 60 yards, make your elevation adjustment on your Optimizer Speed Dial for the distance and shoot at your targets center. If the windage is off at all, adjust the windage on the scope until centered, then move back into 20 yards to insure your shots are still in the bullseye. If so, move your distance to 80 yards and repeat the process. Final windage adjustments are always set at the longest distance you shoot, not the shortest.
If for any reason you are not in the bullseye at the shortest distance after adjusting at a longer distance it typically indicates either your crossbow is not level when shooting (Canted) or something is not properly squared on your crossbow. This implies that wind is not the cause.
After performing these tuning adjustments on my own crossbow I can consistently stay within a 1" florescent dot at 20 yards and I chase the same dot when shooting at 100 yards. I can't always hit the dot at 100 yards, but I'm never more than an inch or two away.
I recently had to change my string and cables on my TAC for the first time since purchase. That was after 3,500 shots on the originals. In order to put new cables and string on, I also had to reserve the timing cord from my QAD HDX Drop Away Rest onto the new Down Cable. This basically meant re-tuning and alignment from scratch. The end results were exactly as they had been and shooting performance did not suffer at all.
If necessary, please send Buzzard Bait a message and ask him for the details on the Zee Rings.
Regards,
Jon