As long as your crossbow utilizes a picatinny rail then the Leapers UTG 4x32mm Crossbow Scope will be more than sufficient for your setup.
Yes. The Leapers UTG 4x32mm Crossbow Scope will fit to your Barnett 400 and any other crossbow that has a picatinny rail equipped.
Yes. The Leapers UTG 4x32mm Crossbow Scope will fit to the existing picatinny rail on your crossbow and function as intended.
If you are having issues with your scope, I would recommend reaching out to Leapers customer service for assistance. You can find their contact information linked below:
https://leapers.com/index.php?act=service&subject=Questions&mobsubject=Questions&midx=185&rpolicy=true
Yes, it can be mounted on the hyper Ghost, however the reticle is designed for bows shooting 300fps. Your bow will shoot flatter, which will effect the aiming points at farther distances.
Pro 5-Step reticle specifically designed for 300fps crossbows with integrated range finder lines. Your bow would shoot more flat, so would not be exact, effect is amplified at distance.
I wouldn't recommend it.
You can use whatever rings you would like as long as they are the correct tube diameter (1 inch).
It is only available in black.
It can be used on any firearm if you really want as long as it has a weaver/picatinny rail on top of it. But this is meant and calibrated for a crossbow. Leapers sells other 4x32 rifle scopes that are meant for rifles.