First post on here! I'm pretty knew to owning firearms, and I'm debating on putting a red dot sight on my 15-22 (picked it up this week for sale on black Friday! Merry Christmas to me!). I like shooting with iron sights, but I would also like to put a red dot on for fun. If I get a red dot, is it easy to take it off and put back on at the range, that way I can also just shoot with irons. I've read I can co-witness but I'd also like to just be able to take it on and off. Once the red dot is zeroed in, if I take it off and put it back on, will it not be zeroed in anymore? Sorry for the dumb question! Thanks for the help guys!

That's what the big thumb-wheel on the side of the sight is for.

It will return to zero close enough.

You can get mounts that will allow you to "co-witness."
I think the whole co-witness thing is completely overblown.
What is the point of co-witnessing?

What difference does it make if the red dot is perched (more or less) on your front sight while the iron sights are aligned?

Do you plan to aim with the iron sights while the red dot is working?

If the red dot is not working, and you can still see your iron sights through the failed device, don't you just line up the sights and shoot?

I couldn't care less about whether my iron sights "co-witness."
Honestly, I don't even want to see the iron sights while the red dot is running.

__________________
WWSSD?
What would Skeeter do?

On the other hand, I've been having a bit of trouble with my astigmatism blurring the red dot on my 15-22. I have a swing-mounted 3x magnifier that works well for clearing things up at distance, but found that co-witnessing the red dot through my rear iron sight (MBUS) really sharpens things up for my eyes. YMMV...

W.E.G., the reason for the co-witness is as you stated, able to work your iron sights if your optics fail as in red dot stops working. It is nothing more than returning your weapon back to basic's to keep you in action during the fight. This was born from battle field experience and not meant to really matter on a 22lr plinker. But with that said, it is good logic since owning any weapon one should be first trained on the basic IRON SIGHTs of the weapon, then add on your special optics, scope etc. etc. Using optics that have electronics have a tendency to "Murphy's Law" stop working when really needed. The co-witness allows for fast back to battle thru the existing optics if needed. In active shooting this system is very much needed. Now shooting paper Zombies at the range, well no threat there but simulated training of "what if I were in battle"... Just my opinion on the matter.

On my M&P 15/22 I have Magpul MBUS front/rear, so I fold them down. On my AR15s I have fixed front sights with fold down MBUS rears. Both AR15 have Red Dot (#1 Aimpoint ML3, #2 Vortex Strifefire), I have trained with the front sight up for a while and am very use to it. It does stick up in my Optic's when using the RED DOT, but it is also a fast reference to putting the RED DOT on the tip of the front sight aperture. Since the front sights are thin, not a problem. The Magpul on the 15/22 is wider than the stock AR sight so I keep them flat. But both are fine by me. I guess it's what you train with that matters most.