There are still some who insist a scope is not needed for the type hunting they do, ignoring the advances of the last 150 years in optical sights. (Even the ultra-conservative US Army has adopted optical sights.) The idea that in some special circumstances open iron sights or aperture (peep) sights might be more useful is not lost on me, but with the inevitable advance of age comes the reduction in visual acuity needed for using iron sights.
I believe that many who completely resist the idea of shooting with a scope have probably got some personal reason, perhaps having sometime in the past used low quality glass or a scope that was not mounted or focused properly for them. However, a person who looks with an open mind at a decent quality scope of appropriate magnification for their type of hunting, mounted and focused correctly for their eye, will likely find they are able to pick up the techniques for proper scope use very quickly.
From what I've learned the last few years, the greatest majority of wild boar hunting is done at short to moderate ranges, say 10-150 yards, and shots farther than 200 yards would be considered very rare. Most wild hog country features thick cover and shots are rarely over 100 yards. This gives the hog hunter the advantage of being able to use many common calibers and rifle/scope combinations also used for short to medium range deer hunting.
The most common mistake in choosing a scope for both deer and hog hunting would be the tendency to "over scope," or buy a scope with higher magnification than actually needed. The 3-9X variable is the most common scope found on modern deer rifles, with it's owner feeling the 9X is what he/she needs to sight in at 100 or 200 yards and the 3X setting is sufficient for close quarters shots. I'll be bold enough to say that 90% of hog (or deer) hunters have no real use for a scope with 9X or 10X magnification.
Thinking it will help when properly sighting their rifles at 100 or even 200 yards is a misnomer, period. Please realize I am talking about hunters and hunting rifles, not serious target shooters, who have different needs and requirements than the hunter. Anyone skilled in shooting a high-powered rifle can shoot nearly identical groups at 100 yards with a 4X scope or a 9X scope(of the same quality). If you are shooting a .270, .308, or .30-06 class rifle, try it and see for yourself. It is truly enlightening.
The added FOV at 100 yards at 4X, rather than 9X, is like night and day. Hence, the true need for a high magnification scope for the serious hog hunter is nil, in my opinion. Simply dropping back one size "category" to a 2-7X variable will save size and weight, along with giving a better FOV at low power for close quarters shooting. A 2-7X scope has as much magnification as your rifle, caliber and any expected shot could require. The 2-7X variables and fixed 4X scopes are probably the most useful hunting scopes ever designed for big game hunting. Once, they were also the most popular hunting scopes, but they seem to be largely overlooked by many today.
Of course, other types of scopes and magnifications are also suitable for hog hunting. I will make some suggestions and observations about scopes with which I've had a good bit of experience and would recommend to anyone.
I will say it again, the idea that one needs a high magnification to hunt big game at short to moderate ranges is plain hogwash (pun intended). I would be willing to bet that many shooters have had bad experiences resulting in horror stories and bad attitudes after trying to shoot game with an overly powerful scope. The scope manufacturers seem to have oversaturated the market with 3-9X, 3.5-10X, 4-12X and 4-16X scopes. (It must be easier to sell useless magnification than to educate consumers about the advantages of lower power scopes.)
Talk to a variety of experienced hunters who have hunted a combination of thick woods, fields and open forests and see how many have actually shot a big game animal at 9X or greater magnification. I bet you will be hard pressed to find even one. I believe you will find most leave their scopes set at two, three or four power and RARELY change it in the field. Some of them (include me) might even admit they have rifles that are among their favorites that have fixed 2.5X, 3X, or 4X scopes atop them.
The reason is that such scopes work, plain and simple. Any big game animal is a large target and can be shot easily at 200 yards with a 4X scope. What this tells us is that we are wasting weight, size and money on scopes we do not need. What a serious hog hunter needs to do is look at his or her type of hunting and the ranges at which hog encounters normally occur and scope for that. Simple!
Perhaps the most useful scope may be one we do not have to worry about having set incorrectly, ever. Fixed powers work and cannot be left on too high a power when suddenly needed. Two of my favorite fixed power scopes are the Weaver K4 and the Leupold FX-II 4x33mm. The Leupold is about as good as 4X scopes get; the Weaver, at $100 less, is nothing to sneeze at. I have both mounted on fine rifles in the 7x57 and .30-06 class and think of them as excellent choices.
I also managed to get an awesome deal on a couple of four power Nikon Monarchs at closeout prices. I've heard the Nikon Buckmasters four power scope can be found at a good price. I'd highly recommend a few other fixed power scopes. The fine Leupold FX-II Ultralight 2.5x20mm has LOTS of eye relief for hard recoiling calibers and the Zeiss Conquest 4x is another outstanding choice.
As far as variable power scopes are concerned, there are a many good choices. The compact Weaver V3 (1-3x20mm) is clear as can be and priced slightly under the Leupold VX-I Shotgun 1.5-4x20mm. Don't be worried about the latter's "shotgun" designation, as that simply means the parallax is set at 75 yards rather than 100 yards and that matters not one bit in typical shooting. This nice Leupold also comes with a heavy duplex (HD) reticle that is great in low light or for quick sighting. This is one of my favorite reticles, bar none.
The similar but more upscale Leupold VX-II 1-4x20mm riflescope is parallax corrected at 100 yards and comes with a standard Duplex reticle, Multicoat 4 lens coatings, ¼ MOA adjustments and other refinements. It is one of the world's great dangerous game scopes. Nikon also makes a very nice 1.5-4.5x20mm scope, but the eye relief is not quite as good as the Leupold for hard kickers. It is a very fine scope, however, and I am keepin' all three of mine! Nikon has also recently released another good low powered scope line called the Monarch Africa Series. Mine is the 1" version and I really like and the #4 type reticle it comes with.
The next logical step up for hunters is the very versatile 2-7 magnification range variables. There is absolutely no shortage of fine and reasonably priced scopes here. Bushnell sells a good 2-7x32mm in their Elite 3200 series and I promise it is a great value. Some have the "Firefly" reticle, which is likely the King of low light reticles.
The Burris Full Field II 2-7x35mm is another excellent value. With it's German #4 type reticle, I think I have a great set-up for low light, bright light--actually, any light--shooting with my Ruger Hawkeye in .338 Federal. It is a very nice scope for the money. Leupold offers Rifleman, VX-I and VX-II line 2-7x33mm riflescopes, a VX-II Ultralight 2-7x28mm and a VX-I 2-7x33mm Shotgun model at just under $200. Weaver has a Classic V7, 2-7x32mm model and I own five Weaver variables, because they are excellent values in today's market.
There are other fine scopes, of course. If one has the scratch, Leupold VX-7 (1.5-6x24mm), VX3 (1.5-5x20mm, 1.75-6x32mm, 2.5-8x32mm) and European-30 (1.25-4x20mm, 2-7x33mm) lines are excellent choices in top quality glass and all Leupolds are made in the USA and come with a lifetime guarantee. All of these scopes would be great for 99% of hog hunting.
About five years ago, I decided to upgrade the inexpensive glass I'd mounted on my growing rifle collection and through careful research (plus some trial and error), I found value-laden scopes at fair prices. I have not regretted for one moment changing to the better brands and models. Every scope I've mentioned, or one very close to it, sits atop one of my big game rifles. I know what marginal scopes are like and I ain't going back there!
A quick mention about just how to attach your new, quality glass to your rifle might be appropriate. For starters, those see-through, see-under type rings are a poor choice. On the fast handling carbines we want for hog hunting, they create balance problems and put the centerline of the mounted scope too high for proper and comfortable aiming.
Mounting the scope as low as possible, in a natural location for your face's position on the stock, is as important as any other consideration in scope mounting. Once you have the proper height rings in place, you must position the scope in the rings for proper eye relief. This means setting the correct distance from your eye to the ocular lens.
On a variable power scope, I would suggest using the low to middle powers to make this adjustment. Shooting at the highest power usually means you have a moment to set your eye relief before firing (by positioning your cheek on the stock), whereas shooting at a close, possibly moving, target requires a low power setting and perfect positioning of the scope, as you mount the rifle quickly.
A final comment on "red dot" type sights. I have some experience with these electro-optical sighting systems, which use a battery-operated source to project a red dot in a scope-like sight. Most have no magnification and have dots of various sizes from 2 MOA to 10 MOA. I have found them to be better than iron sights at all ranges, but not as accurate as a conventional scope at medium and longer range. I can shoot hunting sized groups with my red dot equipped BLR rifle in .450 Marlin out to 125-150 yards and that's all I am looking for. I would suggest a dot size of 2 to 6 MOA for this type of sight. Red dot sights offer maximum eye relief and speedy target acquisition, especially with 30mm or larger tubes. Good seeing, good luck and good hunting!
Marlin 1895/45-70 topped with a nice Leupold VXI SG 1-4x20 with HD reticle
Marlin .308MX topped with a Weaver compact 4X SG scope
Marlin .375 topped with a Weaver V3 1-3x20
Savage 110 in .338/06 topped with a Bushnell Elite 3200 FireFly 1.5-4.5x32
Husqvarna M 4100 in .270 topped with a Nikon Monarch 1.5-4.5x20
Rem M700 Cl in .35 Whelen topped with a Nikon Monarch 4X40