Last season he took eight deer. Seven dropped on the spot, dead in their tracks. One walked a short distance before keeling over.
"That is the beauty of accuracy," said the former Army officer who lives in Columbia. "If you have the right round and hit the right spot, he is going down. The caliber doesn't matter."
Johnson spent years wading through information about everything that goes into shooting accuracy, some of it so complicated that it defied comprehension. Much of the available information was useless to the majority of deer hunters who buy their rifles off the shelf and have only rudimentary knowledge of ballistics or how wind, gravity and air resistance can affect the flight of a bullet.
Many hunters just don't bother trying to learn how to be more accurate shooters because the subject can be so complicated. If they fire their rifle and can hit a pie pan at 100 yards every time, they're satisfied they can kill a deer. Quite often that type of shooting results in a missed shot at a trophy buck, or worse, a wounded deer that limps off to die without being found.
"Once I got into deer hunting, I found out a lot of people just buy a gun and start shooting it," Johnson said. "They don't have any idea what it takes to put a round in the middle of a target. Then I started looking for books on the subject, and they are hard to find. There are articles in publications and magazines, but you just don't find a lot of books on rifle marksmanship."
Johnson decided to do something about that, so he wrote a book that cuts through the complicated jargon of ballistics and brings the keys to accurate shooting down to the common deer hunter's level of understanding.
"Basic Rifle Marksmanship for the Hunter" is a quick read - 70 pages long - and a valuable resource for anyone who wants to improve their deer hunting success. In the book, Johnson discusses in plain language and simple terms what goes into accurate shooting while deer hunting - selecting a rifle, scope and ammunition, zeroing the rifle, ballistics, accuracy, trajectory of the bullet, estimating shooting distances, shooting technique, maintenance and gun safety.
"The idea is to ensure your shooting system is free of flaws and inconsistencies before you encounter a live target," Johnson said. "This will give you the confidence needed when the live action begins."
Since he took up deer hunting, Johnson has gone through six or seven different rifles, "screwing them up, upgrading, customizing and fine-tuning. I'm still learning about rifles," he said. He admits to hunting deer for about 15 years without any real knowledge of how to be an accurate shot.
"I learned there's a lot to making a rifle accurate," he said. "Before getting into this, I could kill a deer, but since I got into accuracy I don't miss as many as I used to and my success rate as far as dropping a deer on the spot has increased. Now I drop 90 percent of the deer I shoot on the spot."
Every rifle Johnson hunts with has been customized to his specifications. That includes adjusting the trigger pull, bedding the barrel, even replacing the barrel with a custom-made barrel if necessary.
Today he primarily hunts with two customized rifles that feature low recoil and plenty of accuracy - a .243 and a .25-06 - both fairly flat-shooting weapons zeroed at 200 yards.
"Those bullets are small and move relatively fast through the air, so you don't have near the drop as with a bigger round, which means you can place the shot," he said. "A .243, for instanced, has plenty of downrange energy, so if you hit him in the neck, it doesn't matter how big he is, he's going down."
His favorite target is the neck because a hit there produces tremendous shock to the entire deer through the vertebrae.
"By the same token," Johnson said, "you may shoot a deer with a .300 mag in the body, and he may run off because you may have missed the vital organs."
Johnson didn't start hunting with a rifle. His first weapon was his granddad's single-barrel, 32-inch full-choke, 12-gauge shotgun he inherited when he was 10 years old - and his early experience growing up in Kentucky was rabbit hunting with his dad.
Following high school and a start in college, he embarked on a military career as an Army officer that included tours in Vietnam and Europe as a commander of artillery companies. After leaving the Army, he completed his degree at the University of South Carolina and began a second career as an administrator with Blue Cross/Blue Shield in South Carolina, a job from which he recently retired. While at Blue Cross/Blue Shield, he took up rabbit hunting again with a passion. But soon that passion turned to bigger game.
"I had never deer hunted until I came to South Carolina," Johnson said.
A friend introduced him to the man who became his primary influence in the sport of hunting whitetail deer - the late Frank Brown
"Frank Brown was a real hunter," Johnson said. "He loved deer hunting, and he was dedicated to the sport. He obeyed the rules, and if you didn't obey the rules he'd put you off the property.
"Deer hunting is a sport and to keep it a sport it should be a challenge, and to keep the challenge in it, you have to follow the rules."
Brown also taught him a lot about shooting accuracy.
The key to accuracy, he said, is not just the rifle, it's the total system - the human body in addition to the rifle.
"The rifle helps, but once you fix the rifle, if you're not fixed, you're still not going to hit anything," Johnson said. "The key is the mental exercise you go through to determine how to hit the target, including trigger control and breathing control."
Those were the lessons he learned from Brown, who died of a heart attack two years ago and to whom Johnson's book is dedicated.
"Frank had a big farm up in Fairfield County and we hunted with him. He taught me the mental exercises you have to go through to be successful at deer hunting - like talking to yourself," said Johnson, who does just that constantly when he has a deer in the crosshairs.
Brown taught Johnson to talk out loud to calm his nerves and steady his breathing.
"Most people in that situation tend to freeze up and their heart is racing," Johnson said. "Frank would talk to himself and to the deer. He'd say: 'Look at that big rascal. I'm going to shoot you. Ain't you pretty? I'm going to kill you.' Then, 'BAM!' he'd shoot.
"If you don't talk, you stop breathing. And if you stop breathing you get nervous - and if you get nervous you're going to miss.
"Other people may think you're crazy, but you won't be nervous - and you can't be nervous when you're deer hunting."
But, Johnson acknowledged, all the talking in the world is not going to kill a deer if the entire shooting system isn't in good working order. That system includes the rifle and the ammunition, as well as the shooter.
"As a field artillery officer, I leaned the principles of ballistics and shooting projectiles and missiles, which are the same whether you are shooting a .22 caliber or a 16-inch navy gun off a ship," he said. "The techniques are different, but the laws of physics are the same, along with wind resistance and gravity."
When he arrived at Fort Jackson as an Army captain, Johnson commanded a training company for two years, teaching basic rifle marksmanship to young recruits. He refined his knowledge of ballistics and the natural effects on the path of a bullet, but that didn't make him an expert when it came to deer hunting accuracy.
"I didn't really get into the accuracy part of deer hunting until about 10 or 11 years ago," he said. "Before then I could kill a deer, but once I got into accuracy, I don't miss near as many as I used to - and I'm still learning."
An entire chapter in the book takes the hunter through the process of zeroing a rifle, step-by-step. Johnson also cautions if a hunter changes bullet weights, brands, lots or designs, he'll need to re-zero the rifle to assure the impact remains on target at the own maximum effective range - the maximum distance a person can zero a rifle for a killing shot with consistency.
"If you have the proper rest and your rifle is properly zeroed and the deer is within your range, you can reasonably predict you can hit the deer and drop it," Johnson said.
For Johnson, accurate shooting isn't just about a take-no-prisoners approach to deer hunting; it's the core principle of being a good conservationist.
"We need to harvest deer to assure the herd stays healthy," he said. "But from a sporting standpoint, to me the enjoyment of the hunt is more about just watching the deer than shooting them, although I will take a deer when I have a good shot."
And that, he said, is another key element to hunter success and good conservation.
"If you know your range and your target there are no difficult shots," he said. But, he was quick to add, there are bad shots.
The difference between a wounded deer and a dead deer, he noted, is where you place the shot.
"The position of the deer has a lot to do with whether I will take a shot," Johnson said. "A head-on shot or if you're looking at the rear of a deer are shots I wouldn't take. I like broadside shots. The idea is to assure the deer doesn't suffer. You want to make a quick, clean kill."
Just one good shot, he said, should mean meat on the ground.