One of my other jobs is covering all things blackpowder for this magazine's sister publication, Petersen's Hunting.
Eye relief is an important consideration since magnum loads can deliver stout recoil. Three inches is the bare minimum to prevent injury.
And what an interesting job muzzleloader editor has turned out to be since no other category with the exception of optics sees as much new stuff as the blackpowder world.
If Rip Van Winkle was a die-hard muzzleloader shooter and woke up from a 20-year nap--or a 10-year nap, for that matter--he would hardly recognize the sport. The changes since Tony Knight's introduction of the first commercially viable in-line muzzleloader in 1988 have been exponential. Rifles are more accurate, easier to load and clean, and more shooter friendly. In a chicken-and-egg relationship, states responded to this boom with special muzzleloader-only seasons. Many whitetail hunters in the Midwest--they number in the millions--are limited to shotguns and muzzleloaders, and as rifles caught up with and then surpassed slug guns, hunters responded in kind by buying lots of guns.
Many states started out with severe restrictions on action types, bullets, and optics. But like the guns, regulations have evolved to allow optics, and that's a move in the right direction since a set of the finest iron sights can cover an entire deer at 150 or 175 yards, a distance well within most any in-line's reach.
I'm sure someone somewhere will argue otherwise, but muzzleloader rifles do not pose any vexing problems for optics makers, so a new crop of muzzleloader scopes soon appeared after the in-line rifle. While the recoil of a maximum propellant charge and heavy bullet can be exciting, it is certainly no more violent than that of a magnum centerfire rifle. Scopes are designed to handle that sort of recoil from the start. There are certain attributes that make some models better than others.
In general, most of us tend to "over scope" our rifles with too-powerful an optic. Even with tremendous gains in propellants and bullets, the average hunter with the average rifle will not see shots beyond 200 yards, and a 150-yard maximum range is more realistic. While a riflescope will certainly aid in a more precise placement of the bullet, there is little reason to exceed 9X, and 7X is more practical. Variable scopes, like in-lines, have advanced to the state of almost absolute reliability, so it makes sense to expand one's options, but I would not feel handicapped in the vast majority of most muzzleloading hunting situations with a fixed 4X, perhaps the grandest of scopes.
Generous eye relief is a quality that will be much appreciated after that 150-grain charge detonates and the heavy bullet exits the barrel as the rifle violently reverses course and puts into effect those undeniable laws of physics. Three inches is a starting point, and 4 or 5 inches would be appreciated by the brow, as most of us tend to lean into a rifle harder the larger the antlers. One option that should be seriously considered is dispensing with conventional scopes altogether in favor of a reflex optic. I admit a bias towards these newfangled optics, but it is one borne purely out of function. Because they are essentially free of parallax, you could hang the sight on the barrel's end for all the eye relief you wanted. The toll to be paid is the lack of magnification. Still, intensity-adjustable dots or reticles are so fine that I have taken shots out to 160 yards and knew precisely where my point of aim was on the animal. If quick shots at driven game are the order of the day, reflex optics are unbeatable tools for making that one and only shot count.
Nikon developed a reticle that closely matches the flight path of a 250-grain bullet fired from a full-length barrel over a 150-grain charge of high-performance propellant. The open aiming circles allow more precise bullet placement at longer ranges.
While most companies pull a standard scope from the line and simply slap a shotgun/muzzleloader label on a 2-7X variable--and there is no trickery or subterfuge in doing such--there are a few offerings that are purpose built for blackpowder guns. Because there is no practical difference in the mechanical requirements, the changes amount to pairing the appropriate power range with a ballistic-drop-compensating reticle.
Leatherwood/Hi-Lux Optics has a High-Performance Muzzleloading (HPML) scope. The 3-9X has a little under 3 inches of eye relief and three extra aiming points below the crosshair that represent the average drop of a 250-grain polymer tipped bullet that leaves the muzzle at 1,950 to 2,000 fps, an attainable velocity with a 150-grain charge of high-performance propellant. Assuming a 100-yard zero, the crossbars should provide aiming points for 200, 225, and 250 yards.
Nikon, always quick to add another useful scope to the line, introduced several years ago what has turned out to be one of the most popular scopes it markets, the Omega Muzzleloading Riflescope. Taking a page from varmint and benchrest optics, the Omega has open aiming circles in place of crossbars, allowing a hunter or target shooter to place the desired impact point inside the circle for precise aiming instead of obscuring it with a crossbar's intersection. The circles, like the HPML, are designed to coincide with the flight path of a 250-grain bullet pushed by a magnum load of propellant at 150, 200, 225, and 250 yards. The Omega is fast with practice and works wonderfully in the field.
To its credit, Nikon explains that there are innumerable variables that can unduly influence bullets and make them appear places they should not, despite what all the ballistic charts say. The lesson here is to take the combination to the range and ground truth the system. Should either the HPML or Omega systems not perfectly match the preprogrammed drops, it is easy enough to find where the circles or crossbars do coincide with the flight path. Scratch out a cheat sheet and tape it to the riflestock and the combination is hunt ready.
Should you decide to take advantage of all those special muzzleloader seasons, be sure both your in-line and your optic are up to the task.