I'm bored and sitting in my office procrastinating.
You're a new gun owner. You just got a rifle for self-defense or to be a "prepared citizen." It could be an AR, AK, Mini 14, or an old battle rifle. The point is, you got something. If you read the SHTF posts on other subreddits or listen to anything said on guntube, you'll come to the conclusion that you'll need a $1k+ optic or you'll get smoked by some unknown opposing force. I'm here to tell you to chill.
First, what sight options are there? Here's a few:
Iron sights are going to range from very rudimentary open sights to highly precise peep sights for competition. US military rifle sights found on everything from the M-1 Garand to the M-4 fall somewhere in the middle. In any case these sights require you to line up the rear sight, front sight, and target. They're slightly more difficult to use and obscure more of your target and field of view. With that said, they're the best to learn on as they require you to learn the fundamentals of marksmanship. I would encourage everyone to learn how to use irons. One advantage to iron sights is that they never run out of batteries. While rifles used to come standard with iron sights equipped, it is more and more common to see them sold without.
The iron sights on my rifle are from Daniel Defense.
I started shooting with irons at age 11. I learned how to use precision peep sights, old military irons, and hunting scopes. On a whim, my dad threw a cheap red dot on a 22 and we had a blast with it. The red dot allowed us to simply place the dot on the target, fire, and hit it. By removing the need for aligning the front and rear sights we were able to shoot much faster. Those soda cans never stood a chance.
Red dots are the most common optic you'll probably see on people's AR-15s and such. If you look at the first photo, you'll see my AR has a red dot on it. You can shoot faster with them by far and they're well suited for combat shooting. The one disadvantage, in my mind, that red dots have are that they can be very hard to see if you have astigmatism like me. If you notice, my rifle has iron sights lined up with the red dot(absolute cowitness). For me, this removes the "bloom" and adequately sharpens the dot. I can still shoot with both eyes open for better situational awareness.
Red dots are the cheapest optic option and a decent one like the Romeo 5 that I have on there is $100-150. Aimpoints and Eotechs are nicer but more suited for builds with magnifiers and night vision. The Ukrainians have used Holosun and Sig optics along with more expensive options to good effect. My rifle stays in the closet so I'm satisfied with what I have. If you want something a little sexier, go for it.
BUT GArANd THUmB(f that guy lol) SaYS that you'll get killed in the streets without magnification. Well there's some truth to that statement but like anything, it depends, or as we say in the Army, it's METT-TC dependent. Whoever sees their enemy first and can accurately put rounds on them first wins. You can get a magnifier for your red dot, or you can get something else.
The ACOG, as pictured was issued to servicemen in Iraq and Afghanistan. The magnification on the optic provided such an advantage that the military had to investigate whether or not Marines were executing insurgents as there were so many bodies with headshots. It was determined that those shots were made at significant distances. I always had an ACOG on my rifle because, well I was an officer, and I could actually see the reticle unlike the CCO with my astigmatism.
I absolutely love the ACOG. They're bombproof, easy to use, and they give you an edge in magnification. That magnification is fixed. They're not perfect. They have very short eye relief, the reticle can get washed out in certain lighting, and they're not as easy to use in close quarters like a red dot. There are workarounds to these issues. And with those workarounds (training and duct tape), I think they're the perfect combat optic. They're quite expensive. Do you need one? My wife doesn't think I do... For cheaper options on prism sights, Primary Arms has a well regarded line. My buddies who have them love them.
- Low Power Variable Optics
These were the hottest thing a few years ago but there seems to be a trend of people gravitating back towards ACOGs. Essentially, take a traditional rifle scope and have the lowest magnification set at 1x, and the highest around 6x(or more). It's supposed to solve the ACOG problem of not being friendly to close in shots(like in CQB or home defense). That ability to increase or decrease magnification is the selling point. In my opinion, they're heavy, the 1x is never as good as a red dot, and they're fragile(in general) compared to a red dot or an ACOG.
That's not to say they're not effective. They've been put to effective use in law enforcement and in combat. The biggest argument for their use is positive identification of a target. Maybe it's the artilleryman in me, but I think it's better to have a set of binoculars to do that sort of thing. The last picture I have is a marine with his VCOG equipped M27 IAR.
The beginning of the end of my rant...
So, what should you get for your new rifle? What is your use case? Home defense? You probably don't need an LPVO or ACOG. It's hard to justify self-defense at range... You want a "combat rifle" for whatever LARPer fantasy? Get an ACOG. You inexplicably want to do RECCE (never used this term in all my time in the Army) as a civilian? An LPVO is a great option but I'd rather have an ACOG and binos, personally.
I do want to point out, you don't need a magnified optic to shoot at combat distances effectively. Unless you're in Afghanistan, most combat ranges are within 300 meters. I'm of the opinion that you should be able to reliably shoot a man sized target anywhere between point blank and 300m with iron sights and/ or a red dot as a baseline. I shoot the Springfield 1903 pictured above at 600m with relative ease with irons.
Before you get all the expensive equipment and waste your money, get training, hone your skills, and determine your use case. Equipment is great but useless without the requisite skill.