Just the one I was born with. With inlines, your eyeball can do a much better job than any boresighter I have ever seen. If you don't believe me, take a rifle that you know is sighted in, put your bore sighter in and see what it shows you. I would bet that you won't even be close. This is also a good way to check out a bore sighter for any type of accuracy.
Eyeball Method.
First, mount your scoped barrel, can be out of the stock, into a sight vise or in a rest of sorts. Can even be some V cutouts in a cardboard box. Just something you can shim/adjust to get your bore in line with the object you use.
Just use a ball or round target at 25 to 50 yards. You can leave your breech plug in and use the flash hole as an aperture to center the round object in the bore. After centering the round object, just dial your scope to center L to R, and then I dial between center and 1/3 up from the bottom, depending on how high the scope is mounted.
Just remember, if your cross hair is above center, you will want to turn in the UP direction to lower your cross hair. If your cross hair is to the right of center, you will need to turn to the R to move your cross hair to the left. It will seem backwards, as you are moving the cross hair to the line of your bore.
Once you have done a few, depending on how far your round object is, you will usually know where to set your cross hairs initially. I have set up several of my rifles to within just a few inches at 100 yards. This saves me the extra time and bullets/powder/primers involved in starting at 25 yards, then 50 yards, before moving out to 100 yards. With this method, I can go directly to the 100 yard mark and be on paper.
Another thing, and more importantly, I can see right away if the mounts and rings are going to be able to keep my scope as near the center of it's adjustments for optimal performance. Not all bases are created equally.
The T/C's have also been known to need a 20 MOA base or need the rear of the base shimmed to keep the scopes from running out of UP adjustment. This will be very obvious to my eye, before I waste the time/bullets/powder/primers shooting.