Walker said there was no proof that Round acted in self-defense, and not enough evidence to show aggravated circumstances, a standard needed to warrant a minimum five-year sentence.
Roman's family had asked the judge to impose a minimum five-year sentence.
Round, of 14336 West Creek Road, Lurgan Township, used Roman's own hunting rifle in the attack, according to court records. Roman was struck so hard and so often that the weapon broke, the records said.
Round told police that Roman had wounded a buck deer and trailed it onto Round's property. Round said he joined in the chase for the deer. A fight erupted when Round tried to stop Roman from shooting a doe, according to Round's statement to police. Does were out of season at the time.
Round told police that Roman pointed the rifle at him and that he attacked the hunter in self-defense.
Before the sentence was imposed, members of Roman's family took turns addressing the court, an option available to families of victims.
Roman's wife, Teresa Roman, said that her husband was a lifetime hunter and a true sportsman who would never shoot a doe out of season.
She said Round had threatened to shoot her husband if he ever came on his property.
Other family members who read emotional statements in court included the victim's mother, Marion Roman; his 11-year-old daughter, Ashley; his stepdaughter Lara Bentley; and her husband, Christopher Bentley.
Lara Bentley called Round a "monster who has no regard for human life. The brutality of his crime speaks for itself. Let's see how tough you are when you start spending time with people who also have no regard for human life."
Christopher Bentley ended his remarks to the judge by facing Round and saying: "Whenever you come up for parole, we'll be there to stop your freedom."
Roman's relatives spoke for nearly 30 minutes. During that time, Round and his wife, heads lowered, clung to each other.
Round had been free on $225,000 bond.
At one point, Round appeared to waver about whether to enter a plea and Walker delayed the hearing. The judge said he wouldn't sentence Round unless Round was sure he wanted to go through with his plea.
Round spoke with his lawyer for 45 minutes before deciding to enter the plea.