Problem you may be having is reticle  float on your big black target.

Aim small miss small.
Try using a smaller black target with white back ground. Everybody wants to sell you something don't like those peal and stick targets even if im shooting my 5.5 x 22 with fine reticle. On 22x its black on black with a tiny red dot. Rarely turn my power really  high when shooting far too.
Why I only use small black bulls on white. Like to keep power setting on same as hunting too.
Best to spend the most money on the best glass you can afford unless its for a  22lr.
Good luck! Don't  need to listen to me.
Im just a old fart with not so good eyes too.

Here's what you asked for:
Bushnell Banner Illuminated Crossfire 500 Reticle Riflescope, 4-16x 40mm
I've not used it, but I think highly of Bushnell.

Now, having found that, let me actually recommend something else:
Bushnell Elite Tactical Mil-Dot SFP Reticle LRS Riflescope, 10x40mm

I have one of these mounted on a Remington m1903a4 (a .30-06 bolt action rifle).  I bought it for a tactical sniper class a few years back.  It can definitely handle recoil.  The reticle has fine lines in the center so you'll be able to see your target clearly.  And, honestly, I find 10x to be far more magnification than I need at 100 yards.  I was able to coax 1 MOA groups out of my 70 year old battle rifle using 40 year old surplus ammo at 400 yards using that scope. 

This is slightly above your budget but the same scope will set you back an extra $100+ on Amazon so I think this is a pretty good sale.  Free shipping too (code: 4GIFTS)

http://www.cabelas.com/product/Nikon-Buckmaster-BDC-Riflescope/1926337.uts?Ntk=AllProducts&searchPath=%2Fcatalog%2Fsearch.cmd%3Fform_state%3DsearchForm%26N%3D0%26fsch%3Dtrue%26Ntk%3DAllProducts%26Ntt%3Dbuckmaster%26x%3D0%26y%3D0&Ntt=buckmaster&WTz_l=Unknown&WT.mc_id=ir10147&WT.tsrc=AFF&rid=10

ACOGS are a battle optic, good for minute of man accuracy and speed.  Very good optic for it's purpose, but it's not meant to shoot small groups.

I agree with the others, ditch the shoot-n-c's and print your own targets and try it with the acog.  You can try shooting it at 50 yards too if that helps.  9x is probably enough though at 100 yards for your case.

The two shots to the left on your target might also be caused by the wind if it picked up.  a 5 to 10mph wind could shift your shot group by an inch.