SIGHTMARKsx 1×24 Shotgun Scope – Part II Shotgun Application

If you have read my other article regarding the SIGHTMARKsx 1×24 Shotgun Scope (The Sightmark COREsx 1×24 Shotgun Scope – Part I, A Simple 1X Sight for Sore Eyes:, you might ask why I am writing a second article that would seem full of redundant material. In actuality, I am writing a separate article simply because the SIGHTMARKsx 1×24 Shotgun Scope (The Sightmark COREsx 1×24 Shotgun Scope is used in a second application, and that is being a companion to a shotgun, which is the intended purpose for the scope.

I also wrote an article regarding the Leupold 1-4x20mm scope (Leupold VX-1 Shotgun Scope 1-4x 20mm with Turkey Plex Reticle Scoping a Defensive Shotgun!:, in which I attempted to take a scope that is intended for hunting and attempting to make it work on a shotgun that is intended for defensive work.  In doing so, I was not being fair to the scope or to the shotgun.  The Leupold 1-4x20mm scope (Leupold VX-1 Shotgun Scope 1-4x 20mm is far better suited sitting atop a shotgun meant for hunting, Turkey or Deer, in states that allow a magnified optic for hunting.

For those states that do not allow a magnified optic for hunting, the SIGHTMARKsx 1×24 Shotgun Scope is an excellent choice.  The SIGHTMARKsx 1×24 Shotgun Scope simply provides a better and more accurate sight picture than what can be obtained with open sights.

Please allow me to be redundant for a bit and post the specifications for the SIGHTMARKsx 1×24 Shotgun Scope.

I decided to mount the SIGHTMARKsx 1×24 Shotgun Scope high so there was no interference with operating the tang-mounted safety on Baa-Baa, the Mossberg 20-gauge Security model, which is my primary HD and PD shotgun. As a result, my first attempt yielded a sight height of 2.5 inches above the center-line of the bore.  There was more than adequate clearance for operating the safety, and I was fairly comfortable with the installation – until I researched ballistics for the Remington Slugger 220-grain rifled slug that travels about 1580fps at the muzzle.  I decided, due to the ballistic information, to lower the scope.  A set of Warne 1” Lever-lock scope rings with a height of 0.375 inches dropped the scope to 1.8 inches above the center-line of the bore. There is still adequate clearance to operate the safety.

Yes, you will see a bit of the front sight in the optic, but the mind focuses on the cross-hairs of the scope as you align the cross-hairs (which incorporate a dot, in this case) on your POA.

The scope will be zeroed at twenty-five yards, which I believe to be an optimum distance for a shotgun used for defensive purposes. While twenty-five yards may be pushing the limit for a spread of #3 Buckshot, it is ideal for the Remington Slugger.  Below, I show the relative ballistics for the Remington Slugger and a sight height of 1.8 inches.

What can be surmised from the ballistics is that the Remington Slugger is a flat-shooting projectile with less than an inch deviation from fifteen yards to about eighty yards.  It is interesting to note that at fifteen yards and fifty yards, the deviation closely matches the caliber of the 20-gauge Remington Slugger!

With the red dot sight that I had been running on Baa-Baa, I had been able to successfully perform a “Mozambique Drill” at twenty five yards. What I anticipate is that the SIGHTMARKsx 1×24 Shotgun Scope will help me become more accurate in doing so, if I do my part.

Returning back to the SIGHTMARKsx 1×24 Shotgun Scope, the clarity of the scope is excellent, I can run the optic with both eyes open, the eye relief is distant enough where I am not concerned about “scope eye,” there is no “flair” with cross-hairs as I am experiencing with dot sight, and the cross-hairs of the scope are just as quick to get back on target as with the red dot sight.

While some might say that not having an illuminated cross-hair may be a disadvantage in low light conditions, illuminating the target makes the reticle sharp as with daylight.  Also, I do not have to worry about a dot washing out in bright light.


If you use a shotgun for the purpose of home or self defense, the shotgun should be “patterned” at various distances to determine the amount of shot spread. In some cases, you may be able to choke the barrel to produce a tighter pattern, but constricting the barrel to much may have an adverse affect when shooting slugs. In a lot of cases, an “enhanced” choke enables you to run both shot and slug without adverse effects.  Defensive shotguns usually are “cylinder-choked” which simply means that whatever bore diameter you have is what you get as far as a choke.

With the SIGHTMARKsx 1×24 Shotgun Scope, you can “subtend” to determine the shot spread.  For example, the subtend of the cross-hairs, the point where the cross-hair goes from thick to thin, is placed on the target to determine how much area is covered by the subtend. As the target is moved away from you, subtend increases. As the target moves closer to you, subtend decreases. This also occurs with a shot pattern; the greater the distance, the greater the shot spread.

You can chose, or not, to adjust the shot pattern though the use of chokes to keep the shot pattern within subtend (as much as possible) at various combat distances.  As I mentioned earlier; however, if you are shooting both slugs and shot, you may be restricted (no pun intended) in choke selection.


A shotgun has to be aimed, regardless of some opinions. The more accurately that you can aim a shotgun, the better the results will be no matter if you are shooting a number of pellets or a single slug.

Although I am relatively proficient with a shotgun without an optic, having a good optic to rely on makes me a bit more efficient. In my opinion, the SIGHTMARKsx 1×24 Shotgun Scope is an excellent optic to use when you need to place a shot (or shots) as accurately as possible on the target. Shot placement is still king – even with a shotgun.

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About Taurian

Taurian is an Oath Keeper, veteran, former LEO and Defensive Tactics Instructor. Until retirement, Taurian had over forty-seven years of experience as a Technical Writer and Training Program Developer. After leaving home at the age of ten without any shoes, Taurian continues on with many years devoted to the keeping and bearing of arms.

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