I recently changed the original square front sight post on my 20" rifle to a tapered NM sight post. Since the front sight can now only be adjusted in full-turn increments (5 moa/revolution), as opposed to 1.25" per notch, would there be any advantage to zeroing again at 200 yds, or any disadvantages to zeroing at 100 yds, and then just counting clicks up to 2, 3 and 600 yards? There is only about a .010" difference in total sight height between the original sight post and the NM sight post, the NM post being the higher of the two, so the elevation should be within a click or two of the original 200 yd zero. I hope what I'm trying to convey is clearer than mud.
Thanks for your input. I've had 40+years of trigger time behind the M1 rifle, but only about 1.5 years with the AR and I'm still learning its quirks and nuances.

Really good thread...........

https://www.ar15.com/forums/ar-15/AR-15-Zeros-and-Trajectories/18-512335/

RIBZ.

Since the Pros from Dover are in the house, what is the best way to mod the rear sight on a carbine to match the narrow front sight?  E.g., a narrow aperture peep to match a .050” front post?  Using the existing carry-handle 6/3 rear?  Is that a reasonable thing - given a 200/300 yard precision goal, not extreme range.  Carbine.

Thanks for the info. I should've mentioned that I shoot xtc matches, not just ringing steel at distance, hence the change to the NM sights.
Thanks again.

.050 is okay. .034 isn't good. Standard .070 is a little chonky, but best that I've tried, so a .062 may be the ticket.

I have the discontinued Armalite NM 050/060 aperture flip. .050 for daylight (.040 is ideal for clear sky/high noon sun). I hand-cordless drilled the 060 out to .100 for lowlight, and happens to shift 4 MOA low for 100yds. I may open to .125.

OK, that helps. Let me explain fully what I am thinking/trying to do (thread drift but on topic, may benefit OP as well as me).

1) have my 20” NM gun figured out, you and others helped me with that earlier this winter.  1-4 glass for it.   Great help I already received.

2) this is in regards to a 16” gun - I found an early gen1 S&W upper at a great price recently. The very early ones with the Thompson Center barrels, 4150, 1/8, 5R rifling, government profile.  Not a match barrel, but they are quite good; very good - I’ve had them before.  My thinking was to put on a ff handguard and mate it to a spare complete lower I have in the safe, put in a RR trigger.

When I bought my RR barrel for the 20” NM gun, I had them send me a .050” front post (part, not installed).  I was thinking that I could put that into the 16” upper, with a carry handle but would need to get a small aperture for it.  I have a spare S&W carry handle for that purpose if I want to go that way, standard .840 6/3 for carbine.  I could just change that rear aperture vs. putting glass on it is what I was thinking.  This is mostly summer shooting in PNW, so clear and sunny (but definitely not so at other times).

My thinking is based on past experience with skiing, sailing, horseback riding, motorcycling etc.  The more you used other equipment, the more you learned about how much equipment was a factor, how much was “you,” and it made you more skilled - independent of the equipment.  (If that makes sense).  So I would shoot both guns at 200, 300 yds but also, I would like to have an extra gun that can shoot adequately to 200 yards in case my step-son and I go to a match and the squadding does not allow us to use the same 20” gun.  I think that is very likely at local matches.

My dad was a machinist in a prior life, and has a well-equipped garage/shop so I can do my own work (and I have a lot of experience, not just winging it); I have pilot bits and could drill out an aperture. I am just wondering if my plan is sound (or I should just put glass on it - the 2nd carbine).  I know it’s a little bit of thread drift (see what I did there?), but it’s close enough I figure OP does not mind. ;)

Long-winded explanation but I figure better to get it out now and get advice from the Pros from Dover as much as possible vs. learning the harder way on my own this spring and summer.

https://www.ar15.com/forums/Training/The-M4gery-Carbine-Chronicle/14-235929/