It has long been accepted as fact that greater sight radius — the distance between rear sight and front sight — can be expected to improve accuracy. Like most axioms, it seems to make perfect sense. The longer the distance between the rear notch and the front post on iron sighted firearms, the less human error there should be in aiming. Obviously, this becomes a moot point with optical sights.
I’ve been shooting iron sights since my dad started me on a .22 rifle at age four and handguns at age nine. Given my current status of geezerhood, that’s more than seventy years of launching bullets. Those seven decades of trigger time have taught me that “longer sight radius always equals greater accuracy” ain’t necessarily so.
It has also taught me that when it ain’t, there will be identifiable reasons.
Case in Point
In December of last year, I shot my annual LEOSA qualifications. The state where I live uses a one to three-yard distance up close, out to fifteen yards, on the generous old Colt Silhouette target known as the B-21. I always do it once with a compact to service-size auto because that’s my usual primary carry, but also once with a snub-nose .38 revolver because that’s my preferred backup.
When it was over, I cleaned both quals with perfect scores. However, my group was tighter with the short-barrel revolver than it was with the autoloader. A quick look at the previous year’s record showed the same thing happened then.
Now, the auto I shot both years was one I often carry and teach with — a stock Gen5 Glock 19 9mm with factory-optional Ameriglo sights. The revolver I prefer for backup is a “hammerless” J-frame Smith and Wesson, most often the Model 340 M&P. However, it’s a five-shot gun and this particular qual course requires six-shot sequences. Accordingly, I shoot it with a short-barrel K-frame. This year’s selection was a stock Smith and Wesson Model 66-5 Combat Magnum with 2.5-inch barrel and loaded with .38 Special ammo. The distance between the face (shooter’s side) of its rear sight to the top edge of its front ramp is right at 4.50 inches. (Why the top edge? Because with ramp sights it gives you a more repeatable measurement. That’s what we’re really lining up with the rear notch and as my mentor, the late World Combat Pistol Champion Ray Chapman, taught, that top edge is what you really wanted to focus on for a precision shot with an iron sight weapon.) The two-inch barrel Smith and Wesson Model 15 I’d shot the year before was obviously half an inch shorter in sight radius. On my Gen5 G19, that measurement was about six inches — an inch and a half greater.
Analyzing the targets, the difference in scores had nothing to do with sight radius per se. I do the vast majority of my shooting aiming with the gun at eye level. This course required shooting “from the hip” in close. The revolver simply aligned better. My hip shots with the Glock pistol went straight forward with “gut shots” but the angle of the 2.5-inch revolver’s grip put every shot into the small tie-breaker oval in the silhouette’s center chest.
Range Comparison
Early in 2024, with a revolver class coming up, I grabbed a few six-shooters out of the safe with a view toward picking a teaching gun. For old time’s sake, I selected the six-inch barrel Smith and Wesson Model 27 I hadn’t shot in many a moon. Fifty years earlier, I used that gun to win my first state championship (police PPC shooting). Its action was tuned by one of the great gunsmiths, my now retired buddy Nolan Santy in New Hampshire. For comparison, I took out another N-frame Model 27. This one sported a four-inch barrel and was tuned by the Smith and Wesson Performance Center. Figuring I needed a “concealment gun” in the mix, my third choice was a stock-condition K-frame Smith and Wesson Model 66 with three-inch barrel. I can thank another shooting team buddy, John Strayer, for this one.
Just to get some comparison, I started with what I’ve always found to be the toughest part of the Practical Police Course for revolvers, standing without artificial (i.e. braced on a barricade) support and firing six shots in twelve seconds from 25 yards. Rather than switch holsters, I just ran it from low ready. The ammo for the day was PMC 132-grain .38 Special full metal jacket, and all shots were fired double action.
The old six-inch 27-1 put the six bullet holes 6.20 inches apart, center to center between the farthest hits and measured to the nearest 0.05-inch. I used to shoot it better…but I was a lot younger then.
The 27-2 with four-inch barrel shot even tighter, under three inches.
And, to my surprise, the K-frame Model 66 with its 3-inch barrel shot 3.40 inches. I was shooting better with shorter sight radii. WTF???
Now, one try each with three different guns, all with different stocks, is not of great statistical value. However, “one try each” is all we ever get, whether it’s a match, hunt, or gunfight; so it’s worth considering.
One explanation might be, We try harder when faced with harder tasks. The three-inch “stock” gun had a heavier double action trigger than the two slicked up by master gunsmiths. I’ve talked to Master and High Master bullseye shooters who think one reason they shoot better with .45s than with smaller caliber centerfires in the same platform is that the greater recoil makes them “hold harder” and focus more. I think that may have been happening with the stock trigger 3-inch gun.
Another factor could be visual focus elements. I started serious competition at age nineteen with seasoned older shooters who had been drilling bullseyes under pressure since before World War II. I was struck by how many of them went from long barrels to short heavy barrels by the late 1960s on their Smith and Wesson Model 41 and High Standard Supermatic .22s. As they’d gotten older, they found that they focused better on the front sight when it was closer to their eyes, and that outweighed for them the advantages of a longer sight radius.
Personally, I’ve found that within 25 yards, so long as you have good sights you can see, sight radius doesn’t matter that much. When I get beyond that, 50 yards or more, I see better accuracy with the longer barrels and sight radii.
Sight Radius in the Real World
The point is, there are lots of things that go into this in terms of barrel length selection. How far do you realistically think you’ll need to shoot? Do you have optical sights, which pretty much render moot the whole sight radius question? Do you have a choice in the matter? The need may come to shoot and a shorter barrel than you’d want is all you have to work with. A friend of mine in Georgia dropped a criminal gunman at almost 25 yards with the only gun he had on him at the time, a Smith and Wesson 642 Airweight .38 Special with 1-3/8-inch barrel. His training and discipline made it work.
My own best shot in handgun hunting was in 1987 in South Africa. We were short on food and needed game meat. An impala 117 paces away dropped to a called spine shot from my first double action round out of the revolver in this article’s lead photo. That revolver is a particularly accurate 4-inch barrel Smith and Wesson Model 629 loaded with J.D. Jones’ splendid 320-grain hard cast .44 Magnum bullet. It should be noted that, shortly before, I had sighted it in at 100 yards.
Sight radius is “A Thing” in terms of accuracy with an iron sight firearm…but it is not, by any means, the only thing. Go to the range and see for yourself.
