Never hunted with any kind of stick and string.

However, a bow hunter buddy that I let hunt my place came up with a relatively new Excalibur crossbow for me to use. I went to Cabelas today and bought arrows plus field and hunting points. Got home and found that they had no nocks so went back to Cabelas and found that they didn't stock nocks.

Any idea where to buy Excalibur nocks?

I use the Excalibur Crossbow bolts and bought them online at Cabelas. They do not really have a knock like a normal arrow has. Here is a link to their sight. http://excaliburcrossbow.com/content/frequently_asked_questions
Here is an answer to your question:
My Excalibur arrows came without nocks on them. Are they missing?
The bow is designed to use a flat butt ended arrow. Your options are either to use a plug type insert which cannot be used to withdraw the arrow from a target in which it has sunk too far, or a CAP insert which can.

Moon nocks are a no-no since they are totally without purpose and can direct the string under the arrow if you don't align them correctly.

Being of the mind that purpose is of more importance than appearance, we continue to use CAP inserts. The reason the rear inserts are threaded is so our T handle arrow puller can be threaded into the end of the arrow to remove it from targets.

Thanks, especially for the link to FAQ's. I have an awful lot to learn in a hurry.

They have a video they send out with their crossbows, you might can find it online. They have a forum also. Great customer service also.

I bought an Excalibur last year and like it a lot. I'm no expert, but I do have now have some experience with it and would be happy to try to help you with any specific Excalibur questions. Feel free to PM me.

I put another scope on it that I had in the closet. The one that came with it got fuzzy at 40 ft. I'll shoot this morning to see if I can hit anything with this scope. BTW, I figured out that the flat things that come with the bolts are the nocks on the Excalibur arrows. I'm good to go if I can keep my fingers out of the way of the string.

Changed out the junk scope that came with it. After about 20 shots I put 3 out of four in about 1.5 inches. The 4th was close so figure that was my fault. Shooting in my back yard in Hurst and can't get a whole lot further than 50 ft.

Gotta go to Bowie this week to meet the County Tax Appraisers re improvements. May as well stay and hunt a couple of days.

The bow seems to have plenty of penetration power at 50 ft. My question is when(what range) it starts slowing down to make it a risky shot. Also, when would it start dropping enough that I would need to shoot a little high?

Get you a some sort of bipod or tripod type shooting rest to support it and your groups will tighten up. 2 years ago I shot a 140# field dressed buck with my Excalibur Equinox Litestuff at 25 yards. It was a complete pass thru with a top of the heart/lung shot. I knew this buck well enough to know he would jump the string after hunting for him for 30 days. He did not disappoint me. I used my 20 yard crosshair on the scope and hit him where I was aiming. So he still dropped a bit even at 25 yards. 25 yards was my max shot range on that buck.

At that range you should be able to robin hood those. I don't have an excalibur, but I am sure its like others. And yes the further out the higher you have to aim. The arrows mine came with sucked and I was all over the place. I bought some new ones and can hit the same arrow for all my shots. Not advised since they aren't cheap to replace. Not saying you have a problem, but something to a least consider.

My scope has lines in it to aim based off distances. Same concept as a regular bow. They are preset for 20,30,40,50 yards. Not sure what scope you put on there but I would think one that has the yardage lines built in would be preferred.

Robin Hood? Who? Me? At 73 yoa, STX pretty well nailed it on a bipod or tripod.

Which scope did you put on your bow?

As to how far out it will kill something, I have shot pigs at 70 yards with a 330fps crossbow using 435 gr total weight bolts tipped with 125gr G5 Montecs. Yes I have a scope that I can reliably shoot that far. I will shoot at hogs and coyotes that far but not deer. Hogs do not tend to move as fast on the shot as deer do. Deer I will shoot to 40 yards if they are very calm, but like STX pointed out some are going to be very jumpy and those 25 is as far as I care to try.

It's a Burris Full Field II variable. I've had it for a couple of years waiting for a reason to use it. I have it on 3. My problem might be hunting at close range. With a rifle, I generally like to sit about 150 yards out, read a Louis L'Amour book, stand up to relieve myself and generally wiggle around some. I hadn't thought about them possibly jumping at the sound of the string. Since it's early, I hope they won't be jumpy. I despise wounding and losing animals. I'll be sitting about 60 or so feet away in a small ladder stand.