It all depends on how perfect you want the shot and arrow placement. 4-5 inches can be a huge difference in a hit or miss in the woods. If I was you i would definitely take the bow in and have someone tune the bow with you. I like Bwana in Little canada, but there are a few places in the metro that can help you out. Gander Mountain would be another great choice.
If your willing to take an hour drive, then take it in and have matt and Barry from Minnesota Archery (Litchfield) help you out.
Your shooting techniques sound fine because of your groupings, but it sounds like the bow should be tuned up a bit.
Here is an interesting article i found on the net, it will explain in detail how and why to paper tune your bow.
What is paper tuning? It's more than just shooting arrow through a piece of paper. It gives clues to changes that should be made to give you perfect or near perfect arrow flight.
Way back in my bowhunting career, about 12 years ago, I purchased my first bow and set of aluminum arrows. The people at the bow shop put a nock set on the string, to indicate where I should put the arrow on the string, installed the arrow rest, sight, cat-whisker silencers and set the draw weight. I took a few shots and was out of there with my new bow, ready to start practicing with an eye on bowhunting for deer, when I felt I was ready. In comparison to the bow I shoot now, the Darton Trailmaster that I purchased was slow but comfortable to shoot with fingers. My ability to hit the target was dependant upon my shooting form and getting a consistent anchor point and release. I began to study books on archery and bowhunting to help teach myself what I needed to know to become a better shooter and, hopefully, bag a deer with my bow.
Changes have been made since then, including switching to a release, a different rest which was better suited to shooting with a release, fiber optic sight pins and other changes. Over the years I have learned much about the mechanics of bows, the physical forces involved, arrow paradox (the flexing of an arrow as it is released), the effects of different point weights on effective arrow spine and what affects arrow flight. I am constantly reading talk forums on the internet about archery and bowhunting to gain more information and to learn from the experiences of other bowhunters. During this time, I learned about paper tuning.
Paper tuning a bow involves setting up a piece of paper on a frame, stretching the paper taught, and shooting field-tipped arrows (not broadheads, which will affect the arrow flight) through it starting about 6 ft away. The paper should be set high enough so it's center is even with the height of the arrow as it is fired from the bow, using good shooting form. A good backstop is placed 4 or 5 feet behind the paper so the arrow passes completely through the paper before it hits the backstop. This will assure that the tears in the paper caused by the arrow passing through will not be affected by how the arrow moves when it hits the backstop. (see below)
As the arrow passes through the paper, the point will pass through the paper first, followed by the shaft, followed by the fletching. The tears are then looked at to determine how the arrow is flying when shot. The point will make a small round hole and the fletching will make a "Y" shaped hole. The location of each hole, relative to each other, will tell you how the arrow is flying. If an arrow is coming off the bow perfectly horizontal, the point-hole will be in the center of the "Y". This is the way you want your arrows to be flying. All the penetration force is being directed behind the point.
See the following examples:
The point hole will be represented by the following symbol: o
The Fletching hole will be represented by the following symbol: X
The shaft will be a dotted line: ------
If you see a tear like this:
X-----o
This means that the arrow is coming off the bow "tail left", meaning the fletching is to the left and the point is to the right when the arrow passes through the paper. There is no problem with the arrow's vertical flight, but the horizontal flight needs to be corrected.
This means that the arrow is coming off the bow ""tail low and tail right", meaning the fletching is to the right and below the point when the arrow passes through the paper. There are problems with both the vertical and horizontal flight of the arrow in this case.
Assuming that you have correctly spined arrows (meaning: based on your cam/wheel type, draw length and draw weight, and point weight, they should shoot well from your bow), adjustments need to be made to your nocking point first, then to your arrow rest, in order to correct any problems discovered during paper-tuning.
Most bow-risers, the center part of the bow which contains the grip, sight window and arrow shelf, that are produced on todays bows have been tapped for center-shot; there is a hole above the arrow shelf which indicates vertically where your arrow shaft should be at full draw. Some types of arrow rests are mounted through the center-shot hole, these are usually on bows that are shot using fingers to hold the bowstring. Your nock-set, usually a brass ring which is crimped onto the bowstring, should be set so your arrow shaft is in the same vertical plane as the center-shot hole. See below:
SIDE VIEW OF ARROW IN BOWBefore you shoot your bow, place an arrow just below your nock set and check to see that, when your string is completely vertical (straight up and down), your arrow should sit perfectly horizontal and the arrow shaft should be roughly in the vertical center of the center-shot hole. This will make any vertical adjustments minimal when you get to paper tuning.
Most arrow rests are adjustable horizontally, moving the arrow closer to or farther from the riser. Center shot is the center of the bowstring. The best arrow flight occurs most often when the arrow shaft is set so it lines up with the center of the bowstring. When the arrow is set up in this manner, the arrow will receive all the kinetic (motion) energy directly down the shaft in a straight line and all the potential speed. If the arrow is set NOT in-line with the bowstring and the arrow is released, the kinetic energy will push the nock end of the arrow to one side, causing the arrow to "fish-tail" (have a curved, rather than straight flight, horizontally speaking)
Start by holding the bow in your hand as you would shoot it. Do not draw the bow. Nock an arrow on the string, put the shaft on the arrow rest and hold your bow-arm outstretched. Looking up and down at your cams, turn the bow left or right until you are looking straight in line with your cams so you can only see the back side of them. Compare your arrow shaft with your bowstring to see if it is line up with your arrow string. If the arrow shaft is not centered in the bowstring, move your arrow rest left or right until the arrow shaft is centered. See below:
BACK VIEW OF BOW, CHECKING FOR CENTER-SHOTIf you are not confident making these adjustments, go to your local bow shop and they will set the center-shot for you.
FLETCHING CLEARANCECheck for fletching clearance: Spray some powder foot spray on your from the nock to about 3" past your fletchings. Then shoot the arrow into a target. Inspect your arrow, looking for places where the powder has been rubbed off by contact with your arrow rest. Fletching contact is the one of the biggest causes of erratic arrow flight. Most arrow-nocks can be turned so that the feathers or vanes of your arrow will pass cleanly through the arrow rest when shot. Make adjustments until you have no fletching contact.
Once your arrow is aligned, begin paper tuning using the instructions in the middle part of this article. Make the following adjustments based on the paper tears listed: Make vertical adjustments, per no. 1 or 2 before correcting rest position for left or right tears
1. Point-high, tail low tear-move your rest down (or your nocking point up) approx. 1/16 of an inch , shoot another arrow and check the tear.
2. Point low, tail high tear-make the opposite adjustments as no. 1. above.
3. Point Left, tail right tear-move the rest slightly IN toward the riser., shoot another arrow and check the tear.
4. Point Right, tail left tear-make the opposite adjustments, as no. 3 above.
Always shoot with a relaxed grip on the bow so you don't twist the bow mid -shot, throwing off the arrow flight. This is called "torquing" the bow. I would suggest shooting with a wrist sling so you won't be afraid that you will drop the bow.
The more you learn about tuning a bow, the less dependant you will be upon your local bow shop, plus, you will have the satisfaction of doing it yourself. Best of Luck.