Bipods are rarely the answer unless you are trained in their use or are unable to assume a prone position. They bring their own set of issues depending on weapon configuration. If possible, shoot off of sandbags or a pack, or use a magazine monopod technique.
You might not be a bad shooter, but if you are shooting 5 inch groups at 50 yards, you are doing something wrong or your weapon is severely dicked up. PMC ammo, while certainly not threatening to secure the winners table at long range, is more than capable of consistent 2 to 3 inch groups at 50 yards. Group size is a function of the shooter, weapon, and ammunition. Sight adjustment simply moves that group to where you want it.
For consistent shot placement, fundamental marksmanship techniques are critical. Here is a thread that talks about fundamental marksmanship:
https://www.m4carbine.net/showthread...l+marksmanship
One thing that might be hurting you is your choice in rear sights.
The traditional rear sight has small circular apertures in which one places the front sight horizontally and vertically centered. A small round hole makes that easier than a large diamond.
I consider the diamond aperture to be oriented toward the experienced iron-sight user.
Sight adjustments:
Most front sights will move the round
about 1" at 50 yards per "click" or detent when at the standard M4 position. If you are using a front sight at another position (such as with a middie or longer handguard) the adjustment will result in slightly less movement per "click".
Turning the sight counter-clockwise will raise the front sight post, resulting in shots going lower than initially. Commonly, the front sight will be marked "UP" with an arrow pointing to the left. Turning the sight clockwise (toward the arrow) will result in the srtike of the round rising, as the front sight is being driven deeper into the front sight base (making it shorter).
Adjustments can be made with pretty much any tool that will depress the plunger. I have used everything from bullet tips to purpose built front sight adjustment tools. I really prefer the tool. If you have never adjusted your front sight, drip a little lubricant into the front sight detent area, as many come from the factory quite stiff and adjustment resistant.
Bookmarks