Boo Custom Strings
Flemishstrings@gmail.com
I have to first explain that making strings is a hobby for me. I own and operate a 4 tech BMW auto repair shop that keeps me pretty busy to start with. If you are interested here is a link to AutoTrend, the company I own and operate.  AutoTrend  I also have a family to spend time with and then there's hunting. So I just cannot produce a lot of strings out very quickly. As a general rule a string will take 3 to 5 days to complete because I like to see them under tension for a couple of days to squeeze out the string maker's wax. This time spent on a jig will reduce the number of times the brace height will change. Delivery time will vary and I think customs really puts a slow down especially any where near Christmas. I can, if you wish me to, expedite the string. The cost is usually up to $18.00 into the US.

If you are new at the crossbow game please do not use anything else but a Dacron string which is what comes with the bow when you buy a new bow. The newer you are to crossbows the more the possibility of a dry-fire. Two bad things happen when you dry-fire a recurve crossbow using a high performance string which is made from anything other than Dacron. One is limb damage. The second is that often the string will whip across your face, possibly causing injury. A Dacron string has enough elasticity to absorb the excess energy that causes damage to your limbs. Nothing is worse than having damaged limbs during hunting season! That is the wisdom behind Bill Troubridge including a Dacron string with the bow. The Excalibur part number is 1994 and it is called an Excel string. It is an endless loop string. Excalibur also sells a Super String. The Super String is Flemish string made from Dacron and has good elasticity for a beginner. The part number is 2097.
 

On the subject of crossbow names I own bows from a several manufacturers. Excalibur, Kodabow and Scorpyd bows are definitely my favorite bows. Each one has it niche. The Scorpyds are fast, very low in recoil and noise and well balanced. The down side (to me) is that the Scorpyd is a compound bow with more to go wrong in the field. You can however change a Scorpyd string in the field but there is a whole lot more that can go wrong when you compare the recurves to compounds. This brings us to recurves and the less that can go wrong the better. 
In recurves Excalibur and Kodabow are kings! Both have different qualities that make them better for certain people. 
Kodabows are lower in noise and recoil. They are extremely accurate but best of all the parts go together like an ultra precision puzzle! I have never seen such precision in a crossbow! They are best served for those who want a recurve but need an auto safety and an anti dry fire mechanism.
Excaliburs are a perfect example of simplicity resulting in reliability and durability. There is no extra anything to go wrong. No cables, no wheels, no anti dry fire, no auto safety means there is several things that cannot go wrong because an Excalibur doesn't have them.
If you are shopping for a bow look at these bows first. If you want speed buy a Scorpyd. I would compare my favorite recurve crossbows by saying that the Kodabow is like a sniper rifle and the Excalibur is like a fine 20 gauge upland bird gun. The Excalibur just feels right when you shoulder it and the Kodabow feels like it's begging for a Harris bipod!


Below is what I think are some important points of conversation.

Mag tipped/reinforced tips vs carved tipped limbs
Before you order please make sure that you do not have carved tipped limbs. The only string that can be safely used on a carved tipped, non-reinforced limb is Dacron. There are no exceptions to this rule. Below are two pictures of limb tips. The top one is a mag tipped limb and the second one (below) is a carved limb tip. Use of any string material other than Dacron is the kiss of death for a carved tipped limb!
The upper limb is a mag tipped limb and the lower one is a carved tipped limb.
Cat Whiskers
Cat whiskers are put on a bow string to lower noise, vibration and shock. I use 3 layers of 2 1/2" strips and serve them on both ends of the string with Fast Flight string material. To date, no one purchasing a string with whiskers has complained about loosing any of the whiskers. They do work and they do stay on the string. The trade off is that they will cost you about 6 ft/sec. If you want the fastest possible arrow speeds do not have them put on your bow. If you are not sure that you want them then have your string made without whiskers. You can always send the string back to have whiskers served on at the same price that you would have paid when the string was built. It will cost you the price of postage to me plus the price of whiskers.


STS

I have done some experimenting with the STS and I really like it on the Excalibur crossbows. I immediately found that you get a great reduction in shock, vibration and noise. I found that if you dry-fired the bow the limbs survived but the rubber bumpers did not. After going through a few of the bumpers from shooting and various friends dry-firing I made some adjustments by cutting the rods that held the bumpers short enough that you can no longer see the rods. Below is a picture of before (first picture) and after. I believe what happens is that when the string hits the bumper the rubber is now supported by the rods in the center and the base as well. I also found that if you made sure that the string barely touches or almost touches the bumpers that the bumpers last much longer (compared to the string touching the pads or bearing down on the pads). If you buy an STS make sure you send in your warranty card so that the bumpers will be warranted for a year. Cutting down the rods will give you a slightly lower brace height. If you want to maintain a higher brace height near the upper brace height mark then you can install nylon or rubber washers over the rod to support the bumpers. Once the rods have been shortened you can always raise the the brace height by loosening the set screws that secure the rods and pull out the rods until the bumpers touch the string, put something between the bumper and string like a penny and then tighten the set screws again. Then install some nylon washers over the rods to support the bumpers. Always use either blue Loctite or clear nail polish on the threads of the set screws so they don't back out. You can also buy some 3/8" aluminum rod from the hardware store. I really believe in this product to reduce shock, vibration, reduce the possibility of limb damage on a dry-fire and reduce the shot to shot arrow speed deviation. The total weight of an STS is 5.5 oz.

All bets will be off this year with the Excalibur offering of their string stopper system. It will be worth the wait. It will be simple with a non-adjustable one inch brace height. It promises a longer bumper life and a bit lighter. The one inch brace height is a good one when a string stopper is installed on a bow. When a string stopper is installed there is no more "sweet spot".
Left is as the STS comes out of the package. Right is what it looks like when the rods are shortened.
An installed shortened STS. Take note of the brace height and the lack of gap between the bumper and STS bracket.
On top of the bow is the Ground Pounder Mount made to put your quiver on top of your bow.
String Care
Wax the whole string every few hundred shots and let the wax sit overnight or longer. At the end of a day of shooting wax the serving and allow it to soak in overnight and remove any excess before shooting. While shooting, wax your center serving every 30 shots or so by just rubbing the serving to redistribute the wax. You only need to worry about the section that rides on the rail when you are shooting and you need very little. I prefer Dalton 2000 High Speed String conditioner (http://www.daltonarchery.com/wax-conditioner.php) because it is very slick and very soft. Being soft allows it to be absorbed easier than a thick wax which is especially important to the string fibers under the serving. Any excess wax gets shot off in a hurry when using Daltons leaving the string free of speed robbing excess weight. Also, any real excess wax may end up in the trigger unit which may preclude the use of your bow until the bow is sent in for repairs. Any rubbing in of wax should be done with your finger or thumb. Using a hairdryer or leather may get the string too hot. When waxing the string just wipe the wax on, do not rub the wax into the string hard at all because it may remove the string dye or make the string "hairy". The string loops are often forgotten but they take a lot of impact so don't forget to wax the loops when waxing the string. Ideally it would be minutely better to use bee's wax on the twisted part of the string near the loops. The purpose of the wax is to reduce frictional wear of the center serving at the deck and the latches that hold string back, prevent water from entering the string and to prevent strand against strand friction.
 
Once in a while take side off and rotate it half a turn then do the other side and rotate it the same way. The purpose is to wear the serving on both sides of the string and get more mileage out of the serving.

How do you raise the brace height? Take one side of the string off and while looking from the side of the bow that you just unstrung turn the string counter clock-wise. If you look at the serving you will be tightening the serving when you shorten the string.
Making a Crossbow Less Noisy
Much has been said about making a crossbow less noisy. Most of what gets said is stupid to say the least. It is your bow and if you want to shoot it and have less noise then you should make it less noisy. Now making it so quiet as to have a deer not hear the string released or the arrow launch is another story. No bow is so quiet that it will not make an alert deer try to jump the string. It may or may not duck the arrow but an alert deer will hear the shot and or the arrow before it hits. A deer that is not on the alert is another story. I have shot a few whitetails past 30 yards that had their tails down and angled away from me (ears pointed away from me) that didn't even flinch on the shot that killed it.
 
Another reason to make your bow more quiet is the pleasure robbed from you when shooting at a target. I find it quite distracting to shoot a crossbow with a Fast Flight sting. Then there is your neighbors who have to listen to the noise who just might complain.

Last but not least when you lower the noise level of your bow you also lower the vibration and shock. Shock and vibration will loosen fasteners and mounts. You will also get better long range accuracy. You also get the bonus of being able to watch your arrow fly to it's mark through the scope. Michael Riesterer (920 775 3642) makes wooden stocks for crossbows so he's the best person to go to. You can see a few in the last page of this website. They are truly custom stocks and Michael makes a wonderful stock! 

The most quiet, low shock/vibration set up that I have come up with is a bow with a wooden stock, a Boo string, an STS and cat whiskers which describes my Excalibur Y25. It is so quiet that someone dry-fired it about 20 ft from me and all I heard was the arrow keeper buzz. It still is not quiet enough prevent an alert deer from jumping or trying to jump your string but it sure is nice to shoot. While sitting in a stand I've often wondered if a big buck is 50 or 100 yards behind a doe. So if I whacked the doe with a low noise crossbow would a deer 50 yards behind the doe hear the shot? I can tell you that the noise is so low from my Excalibur Y25 that I know he won't.

I will tell you that almost all of the people that poohoo a person trying to make a crossbow more quiet are the ones who have not heard my Y25 or ones like it!
Some very cool high speed footage of some crossbow strings in action at a website called Crossbow Review

http://www.crossbow-review.com/TechCorner/TechCorner.htm
String speeds

An email sent to me by a pleased customer.

Hi Don.
Well here goes the chronograph used is a Beta Master Chrony, with a new 9 volt battery installed. The temp outside was 78 degrees and a clear blue sky above. Time was 11:30A.M. Date 8-25-08. Arrow used Easton C2 20 inch in length with 4 inch plastic fletch. Excal type. It weighed 273.8 grains bare and a 125 grain tip was used. A new 2008 Vortex was used to obtain data. The string was set on the top line. The first set of numbers used are with a factory string sent along with a new bow.
306.2
301.9
305.5
304.7
307.5
307.5
Adv velocity is 305.55. Extreme spread is 5.6 F.P.S. Kinetic energy 82.94 Ft. Lbs.

Boo String 40 strand made with loving care, and served with Halo
316.1
316.8
316.6
317.1
316.4
316.5
Adv velocity is 316.58. Extreme spread is 1 F.P.S. Kinetic energy 89.04 Ft. Lbs. Calculations done using Archers Edge program.
This string had about 25 shots on it before test.
Please note noise and shock level were about equal to factory string noted above.
Don I hope this works for you, Keep up the great string making, Russ
Which way do you twist to shorten the string? Well especially on a Flemish string once the string is on and it has been twisted to attain a decent brace height it's easy to figure out. But people have a problem figuring it out on a brand new endless loop string like the one above. Look at the end of the serving on your right. Check out the end of the serving thread. If you were to twist the string counter clockwise as to make that end of the serving thread come towards you you will shorten the string which will raise the brace height. As a general rule you can bet that almost any string, when viewed from any end will shorten when twisted counter clockwise, that is assuming the string maker is right handed. I won't go into a discussion about why but just trust me. So just twist one end and it will shorten the whole string evenly and will actually tighten the serving. Which brings another point. When you get a new endless loop Excalibur Excel string put it on with a few twists even if you end up with a brace height above the highest brace height mark (the one closest to the shooter).
 
So what do you do when you get a new string and it sits too high? Well install it as I mentioned with a few twists and  leave it over night. It will elongate and the string will sit lower with some time. You can wax the string really heavily and grab the string and rub it to make it really warm. Use your hand only any vigorous rubbing will cause enough heat to damage the string or chase away the wax that acts as a lubricant between the string strands. But some heat from rubbing with your bare hand will accelerate the elongation of the string.
Brace Height
When talking about brace height on an Excalibur crossbow it is the distance measured between the string and the joint where the riser and the rail meet. On newer bows there are two lines faintly engraved into the deck surface within a couple of inches of the joint between the end of the rail and the riser. That is the factory's recommended brace height range so keep it somewhere in between those lines. Where do you keep it? It really is a personal thing so shoot the bow and play around with the brace height to see where you like it. A lower brace height will give you a couple of more ft/sec but a bit more noise and vibration. A high brace height will give you a smoother shooting bow. Once you add an STS to the bow brace height does not cause more or less vibration.
Most keep it a string width or two below the highest mark.

If you want to raise the brace height you have to shorten the string. Conversely you have to lengthen the string to lower your brace height.
I suggest that you start with a brace height of one inch. Bill Troubridge (owner and founder of Excalibur Crossbows) and Kenny Barr (2 time 3D World 3D Champion) both shoot a one inch brace height. Go as low a brace height as possible not the highest. You'll hear many parrot a high brace height. Ignore what you hear and find your own but start around one inch.
Below shows the brace height marks on a recurve Excalibur crossbow. The low brace height mark is left of the string and the upper brace height mark is to the right of the string.
"a" is where the brace height is measured from, "b" is the lower brace height mark, "c" is the high brace height mark. The brace height of your bow is measured from "a" to the string.
I strongly suggest that if you do not use an STS then you mark the side of the rail with a paint mark as in the picture above. If you do that you can accurately and quickly confirm your brace height. This is extremely important to accuracy by giving you a consistent shot to shot release of your arrow yielding more consistent arrow speeds as well as consistent point of impact for your arrows.

Excalibur Matrix bows
In regards to Martix bows. Some of the Matrix bows come with a string stop called R.E.D.S. Also available are Danny Miller's string stoppers. Keep your Excalibur Matrix bow strings about 1/4" from the rubber bumpers of either string stopper. That will yield better accuracy, less noise and a longer lived string.
Arrows
Aluminum or carbon graphite? Both are good choices! It is a fallacy that carbons are either straight or broken. They do on rare occasions become less straight. I don't know if it is caused by repetitive impact in the target or caused by heat or bending when pulling them out of a target but I do know that I've found arrow shafts after lots of use no longer close to being straight.
 
Aluminum shafts do bend if treated rough. Aluminum shafts get dented if hit by another arrow but them carbons get damaged if the same thing happens. The result of a small dent in an aluminum shaft is nothing but the result being a dangerous projectile that may come apart when launched! When handling damaged carbon arrows splinters are a drawback of  carbons when pulling them out of a target or when game is shot and the shaft breaks. Broken shafts in deer is somewhat common and ingestion of the splinters is a real issue! This is not to steer you away from carbon shafts, just be careful if your carbon arrow breaks when you've harvested a deer. Be careful when field dressing or butchering your deer if your arrow broke. If you bring the deer to a processor and the arrow shattered inside the deer let him/her know that.

Without question carbon arrows are noticeably less noisy.
 
Inserts in aluminum arrow are a snap to remove. Just screw in a target tip and heat it with a propane torch and pull on the tip while the tip is getting hot. Do not heat the shaft and do not get the tip red hot. Removing an insert from a carbon arrow with heat can easily damage the shaft. You can try the same thing on carbons but I think you are best off to just cut the shaft and end up with bunch of 19" arrows. A 19" arrow will work just fine. When using a 19" arrow your broadhead may sit in the forward pocket of the riser of your bow but here is lots of room for a conventional broadhead.

Which one is better? I don't have a clue. If you want to have an arrow that withstands rough treatment when pulled out of a foam target then use carbons. But aluminum arrows are cheaper and the larger the second 2 numbers of the size the thicker, heavier and tougher it is! (an aluminum arrow is described by 4 numbers ie 2219)  If you want to reduce the damage done to arrows from target then use a bag target(only with field tips). You can make life much easier by using an arrow lube (Woody's and Scorpion Venom are two that come to mind) and one of Danny Miller's arrow pullers. Only apply arrow lube to the first inch or two of the arrow. Below is a picture of Danny's puller, it works!

FOC, Fletching & Things
Much has been said about FOC. FOC means forward weight of center. It is a description of how much more weight in there is in the front of the arrow measured in percentage. The standard formula is F.O.C. % = 100 x (A-L/2)
                                                                                                                                                             L
L is the finished length of the arrow and A is the distance from the balance point of the arrow to the rear end of the arrow.  Here's a good FOC calculator.   http://www.archery-engineering.co.za/conversions/foccalculator.htm
It is generally accepted that you want a minimum of 10% FOC and up to 18% or more. I have not measured FOC to get an actual number for years. I know that by assembling most common combinations of shafts, inserts, fletchings and tips that you will get at least 10% FOC. In my experience I've found that if you put as much off-set as you can to a Blazer vane as well as use a helical clamp you will get low FOC set ups to fly extremely well. The purpose of the FOC is to put more weight in the front of the arrow which makes it easier for the fletchings to steer. What I found is that if you increase the fletchings ability to steer by making it's "bite" in the air (by increasing the offset of the fletchings) you end up with much more stable arrow flight. You do this by using a fletching with lots of off-set, use a helical rather than a straight fletched arrow and use Blazer vanes. Brass insert can be used instead of the standard aluminum insert to increase FOC. High FOC is probably the easiest way to attain stable arrow flight. But sometimes you get a poorly flying arrow set up and the cure is often what I described earlier. I use aluminum front inserts if I want an arrow to go fast but most times I do use brass inserts for deer hunting.

A source of poor arrow flight is a broadhead that is not aligned on the same axis as the arrow. Most times it is caused by the front insert face not being square to the arrow shaft. Obviously if the face is at an angle then the broadhead will be pointed off in an angle. When the broadhead is misaligned it will steer the arrow with it's blades. A great way to correct that is by using a G5 ASD to square the front insert face. Some broadheads like the Magnus Stinger do not use the front insert so it isn't an issue but it is an issue with most broadheads because most do contact the front arrow insert. It is a simple operation to square the shaft and takes no time at all. Here's a link to G5's instructions.
  G5 instructional videos

Arrow weight is a much talked about subject. Some like light and some like heavy. Heavier arrows make for a much more quiet shot and fast light arrows make it to the target faster and flatter. It is much easier to make a heavy arrow fly accurately and lighter arrows need more attention. The more I fart around with light arrows the more I like them. I recently made up some minimum weight arrows (350 gr and 19" long) and found that if I put lots of helical on the Blazer vanes they were very accurate out of my Vortex, even at longer distances of 50 yards! The trade off was noise which was negated by my strings, cat whiskers and an STS.

To set the record straight the rotational effect of vanes or feathers is desirable because you want to even out any differences in the arrow. Arrows are not perfectly straight, broadheads are not perfectly aligned, fletchings are not perfectly symmetrical and other unevenness will cause an arrow to not fly straight if the rotational effect of the fletchings were not there. This "stabilization" is not truly like a gyroscope. Why this is important to remember is because when you shoot broadheads you have the most potential for unevenness when the tipped broadhead flies  through the air so you want as much offset as you can live with to achieve good accuracy. The down side of more offset is loss of speed but that loss is minor. But I'd rather hit what I am aiming at slower than missing at a higher speed!


I am by no means suggesting that a beginner start with light arrows. I think someone new will be best served with the standard custom arrow which is a 20" aluminum or carbon shaft, fletched with Blazers with as much helical as possible with a brass front insert. On the other hand there is nothing wrong with the arrows set up that Excalibur sells. It is in fact a good starting point because they now come with 150 gr Bolt Cutters that give you a higher FOC. Start with that and when you want to experiment talk to someone like John Neilson (see Big John's Custom Arrows in my links page) and try something new/different. The advantage of using an arrow with brass inserts is that you get to use 100 or 125 gr broadheads which are the most common broadhead weight giving you a wider variety of choices.  Experimenting is good!

Sighting In Your Crossbow Scope (Excalibur Varizone or Lumizone)
It really is a simple task that many have never done correctly.
 
You need your vertical reticle to be plumb. It sounds easy enough to eye ball it but having your vertical reticle perfectly plumb or vertical is critical to using the 30 and 40 yard reference marks.
 
Start by having the bow set on a base like a gun vice that you use to hold a rifle for cleaning. This will hold the bow so that it won't move when you are making adjustments.
 
Next set a 6" level to the top of your rail and adjust the bow until the bow is level.

Now at 10/20 yards put up a string with a weight that will be in view of the scope.

Back to the bow. Loosen the scope rings and rotate the scope until your vertical is perfectly inline with the plumb line. Tighten a little at a time in a cross pattern. You are now ready to sight in your bow! Follow the instructions below and you'll be hitting the bullseye all the way to 50 yards.
  
You will need a target, a solid rest and a minimum range of 40 yards. Make sure you are happy with your brace height and your arrows.
First is to shoot from 20 yards and zero in your center crosshairs on the bullseye of your target. Once you have done this you never move the crosshair adjustment again.
Second, you step back to 40 yards. Place your center crosshairs on the bulleye and shoot a group of arrows while holding the center crosshairs on the bullseye. Your group will be several inches below the bullseye. Now while holding the center crosshairs on the bullseye adjust the speed ring so that the second cheveron down is on the group of arrows you just shot. Tape the speed ring so it will not move. Now double check your 10, 20, 30 and 40 yard groups at the respective ranges.
Damage from rough latches
Damage from "over cocking". The damage is right inline with the circled part of the trigger unit below.
This is what damages the string when "over cocking".
Serving cut from a damaged aluminum nock or just sharp edges of the nock.
Repair of Rough Latches That Eat Servings
The serving on your bow should easily last over on hundred shots and up to a few hundred shots if everything is perfect. Sometimes the serving gets damaged or worn early and here are some things that can cause it.
The first one is damage to the serving that you'll see that coincides with the edges of the rail or deck. It is caused by the operator "over cocking" or pulling past the point of the bow being cocked. It can be prevented by not cocking too far and minimized by breaking the sharp edge of the end of the string slot. Using a small knife blade you can slowly carve off the sharp edge.
The other way the string can be damaged is by rough latches. This damage obviously coincides with where the latches grab the serving and is more prominent on the right side. Very little roughness is needed to damage servings and the higher poundage bows suffer more. Anything less than a perfectly smooth surface on the latches will accelerate serving wear dramatically! For those who shoot a couple of arrows to verify the point of impact and then a couple more when hunting you may not notice it. If you are an arrow junkie like me and shoot several hundred shots a year you may see it in as many as 50 shots and have to replace the serving within 100 shots. This is not necessary and can be prevented by following the instructions below. But my first recommendation is to contact the shop where you bought the bow to have it repaired by the factory or factory warranty depot.

Tools needed;
One quarter inch wide strips of "sandpaper" in 3 grades.
15 micron (1,000 grit)
5 micron (2,500 grit)
.5 micron (9,000 grit).
The backing on these abrasives are suitably tough to do the job and can be ordered from Lee Valley Tools. Do not buy the adhesive backed sheets (PSA).
http://www.leevalley.com/wood/page.aspx?c=1&p=33004&cat=1,43072
One and a half inch wide masking tape about 6" long.How To Do It
Place the tape all the way back into the string slot as shown in the picture above to prevent anything from dropping into the trigger unit below. If anything drops into the trigger unit you can have an unsafe condition so pay attention when you are working on the bow and keep the bow pointed down so nothing can roll back and drop into the trigger unit.
Use an arrow to engage the latches as if the bow is cocked.
Starting with the most coarse grade of abrasive wrap around one of the latch fingers and start polishing for about 20 strokes and look at the rear surface of the latch. If you see a perfectly smooth surface then proceed to do the same thing with the next finer grade of abrasive. If it isn't perfect then cut another strip and go at it again. Do this as many times as necessary. You will need some kind of bright light to see the surface and you do one latch at a time. You want a perfectly smooth surface before continuing. Once the surface is perfectly smooth and without imperfections continue with the rest of the abrasives. You will end up with a mirrored surface and a serving that will last a few hundred shots. Do not forget to clean everything up with a Q-Tip and some paper towels.
I want to stress that if you are not 100% comfortable with this and or do not understand the procedure then send the bow back and have it done by someone authorized by the factory or the factory itself. If you are in the US contact Danny Miller at Horizontal Archery in Sardis, Ohio @740-483-2312. In Canada call Excalibur @1-800-463-1817
If you choose to do it yourself you are of course responsible for your actions good or bad.
The material I describe and suggest you use are very fine abrasives and if used properly cannot remove any real amount of material. Do not be afraid to do what I suggest but you must understand what is being done and what your target is. Please feel free to contact me by email or phone.
Flemishstrings@gmail.com   416 566 7966


Serving Jig

I have provided a couple of pictures so that you can make your own jig to hold your string while reserving. The purpose of my design is to allow you to inexpensively make something that will provide you the ability to put a great amount of tension on your string. This will prevent the string from unwinding and will facilitate a tighter serving.

Here's a link to some instructions on how to reserve your string. Look to the bottom right of the page.
http://www.crossbow-review.com/TechCorner/TechCorner.htm

New shooters
One last but very important point to consider. If you notice in the order form I ask how long you have been shooting a crossbow. The reason for that question is that I want to identify those who are most likely to dry-fire their crossbow. The reason Excalibur Crossbows includes only their Dacron string with the bow is that you are most likely to dry-fire a crossbow during the first while of owning one. With great regularity new comers to the sport will dry-fire their bows when distracted during the routine of cocking, putting the safety on, loading the bow, acquiring the target flicking off the safety and shooting. I mention the routine because until the routine is embedded in our brains it takes only a minor distraction to mess you up enough to have a dry-fire. Take this warning seriously. A dry-fire with a high performance string can result is splintered limbs. My advice is that if you have just got your bow stick with the Dacron endless loop string that comes with the bow. If you have been shooting a crossbow for 6 months to a year then think real hard. After a year of shooting I think most will be very unlikely to have a dry-fire. As I mentioned earlier I believe an STS will lower the chances of damage to your limbs during a dry-fire. I have never heard of a limb coming apart on a dry-fire on an Excalibur crossbow but often what happens other than a splintered limb is the string whips off of one side and laces you pretty hard across the face! It could be your eyes! Be careful there is no sport where stupidity is without consequences! My official position is to wear safety glasses when hunting or just shooting. I wear corrective glasses and the benefits are protection of your eyes (that you only get two of in life) from;UV radiation, reduction of glare, protection from twigs or branches when thrashing through the bush, protection of your eyes during a dry-fire when the string comes whipping across your face and during the remote possibility of a carbon arrow shattering when shot.
If you need to contact me or ask any questions my email address is Flemishstrings@gmail.com