I have a Bushnell Bore Sight with multiple adapters for various calibers, I have been looking for a bore sight for the 17 HMR, is there one available for the set without buying the entire set?

Its called a bore sight..

Boresighters Scope Mounting Tools Optics
https://www.sportsmansguide.com/productlist/hunting/optics-scopes-sights/bore-sighters?d=115&c=134&s=174&sb=plh

The only way to sight in is to bore sight or use a bore sight laser
then put rounds down range at the target to get the point of aim and point of impact to converge

Depends on the scope and rifle type to which it is attached.
I invested in an inexpensive laser bore such as this one for an AR: SightMark AccuDot Laser Bore Sight - 223 Model SM39001 (for AR-15)
Once the scope is mounted properly, and assuming you have not made any vertical or horizontal adjustments, set the rifle on a stable platform, insert the bore sight, point it at a target 50 (rimfire) to 100 (AR) yards out (works best in low light situation).
Once you have the laser centered on your target, make elevation and windage adjustments as necessary placing the scope cross hairs over the laser. Remove the bore sight and fire 3 rounds, then fine tune elevation and windage.

Or did you really mean bussbnell ?
Bushnell Bore Sighter

Instructions for Bushnell Magnetic Bore Sighter eHow

The sighting sounds about right to me meaning to you need to adjust the cross hairs i the opposite direction to where your point of aim is. If your sight is off 1/4 inch to the left you need to bring the barrel to the right to compensate and that's what the bore scope/site is doing. Think opposite and you'll have that tuned in a few seconds. I don't doubt that you have the correct mounting hardware BUT, it's from center bore to center scope what 2 inches so at 25'? Depending on what caliber I'd say at 25' you need to hold 2 inches high for center target. I'll just guess that you might not be able to get a zero until say about 25 yards with a 22 short. A larger bore/caliber will extend this out to possibly 100 yards.
I'm going to give you a link to a bullet trajectory chart so you can sort of see what it is I'm trying to write. you may need to cut and past this in your browser window.

http://www.chuckhawks.com/rifle_trajectory_table.htm

Here is another chart that shows a bullet drop from the muzzle.

http://www.chuckhawks.com/bullet_trajectory.htm

Hope this was a help have fun and be safe

easy this one!!!! undo the eye end of the scope and slip under the scope 3 strips or so of 35mm film then nip the scope back down this will lift the point of aim well above what you need,,,
do your self a faver though,,,throw away that bore sighter,,,and bore sight the scope at 100yds first,
but clamp the gun in a gun vice when sighting it in,,,,you need to get rid of all the wobbely bits first?
gess whats the bigest wobbley bit,,,,yep,,,,,you are!

i would start by supporting it on a table, if you don't have a bore sight look down the barrell or side of the barrell, holding it steady look into the scope. make them match the a spot on the wall, keep adjusting the scope until they match. this will get you close before you shoot. i would set up a target at 25 yards. set the scope close on left, right, up and down. move out to 100 yrds and shoot a 3 group pattern. let the barrell cool, make adjustments and shoot again. it should be set.

continue to adjust the wind-age. If your problem persists I would suggest turning both to a random point and re-start sighting the gun. If that does not fix the problem return the sight because this most likely means the wind-age is disconnected.

A quick and easy way to bore sight your rifle, if it is bolt action only, or an AR, mount the rifle in a cardboard box with cutouts so it will sit without tipping, remove the bolt and sight down the bore at a target 100 yards away, a mail box, or the corner of a building, make sure the rifle doesn't move, then peek through the scope, it should be seeing the same target your bore is seeing, if not, adjust your scope to it, if it won't travel that far, shim the front with pieces of 35 mm film. then check it again, if you can get it to stay there, it will put your bullet on paper at 100 yards.

if it is verry tight back it off a little bit you dont want to break the seal.i have never been a big fan of the laser bore sighters.i have had a cpl and both were inaccurate.BSA makes a good bore sighter for 49 bucks.try a cpl shots with it and find out how far you are truely off.remember 1 click is 1/4 inch.in 100 yrds.in the army we had all the ammo we needed to sight our rifles in.but here in the real world with ammo prices so high a good bore sighter is the way to go.