Having a 270, 3006 & 308. Question is better to sight in O at 100 or 200 yd. looking at ballistics on some ammo a smaller placement at 200 yds O for lessor yardage than O at 100 for longer yardage.
What's the experts opinions?

And here we go

What yardage are you usually shooting game? Zero at 100 and hold/dial beyond that depending on your optics. P_102

I would say depends a lot on your type of optics

Since you will only be roughly 1.75-2" high at 100 yds if you sight in at 200 yds, the 200 yd zero gets my vote. Even then you'll be roughly 6-8" low at 300 yds which will still kill a mature deer. For probably 40 years I sighted in my big game rifles 3" high at 100yds.

What scopes?

What's the minimum and maximum shot distances?

This was just a general consensus question. I sight all my rifles at 100. Just one of those thoughts that might get one in trouble, like several have stated already - "here we go"

What kind of rig are you running? We are not all bad lol, but this will start an argument eventually and we cannot change that.

Theory holds for most deer cartridges, zeroing 2" hight at 100 yards puts one dead on at 200. In actual practice, you should, without fail, actually test this theory by shooting at 200 yards. If you're shooting deer under feeders then zero your gun at the distance from your blind to your feeder. There's no reason to make things any more complicated.

If you want more than this, then you need to actually shoot your rifle at longer distances, 300, 350, 400, 450, etc.

200

The way i see it, your 0 needs to match your hunting range, i know where i hunt i won't have a shot over 150yrds, i zero mine in at 100 and adjust my shot accordingly while hunting

it's a looong time till Deer Season, and best to get this subject addressed while the Gun Range is not too crowded...

Several gooder than average answers so far from the guru's ...Well Done Y'all! ...and as long as it's only WET today with NO HAIL I'm OK with that, and a good way to spend a did I say a WET Tuesday ???

Was gonna practice using my new 1st set of 2 bifocals readers, but now I can practice wearing my new Computer scripped & normal lenses too, bur doan't hold any hope for my spealling or typing being improved. Oh Well some things never change...
Ron

This will get interesting

Any bets on whether we can milk this thread for a 100 post's??? A little early in the year for that but....mebbe sumbody can 'splain MPBR too to "help" with the subject the OP wanted an answer for...and the pro's & cons of BDC's X' Duplex Crosshairs.

FWIW I don't own a BDC scope anymore for the 1st time in lotsa years - don't miss the lense clutter either...and will take my chances with my 50 year history using MPBR's with a Duplex and proven at distances in each caliber/bullet weight/ MV's with the samllest MOA's that the combo shoots at the basic 100 yard target distance ....but then I have now adopted a self imposed max range to shoot a game animal at as "verified" with a Rangefinder & depending on caliber rifle in hand ...IMO hogs & 'yotes don't qualify for that Game Animal standard either...in other words ..if'en I can see'um than mebbe I can hit'em is my attitude on hogs & 'yotes.

Being retired gonna help with the time commitment at the Range too...
Ron

Here is my token post to get to 100.
If its a hunting rifle used only for hunting big game then 100/200 yards really doesn't matter.Do what you feel makes you the most confident.
For flat shooting varmint rifles I normally sight in at 200 although one of my 22-250's runs 4000fps with 52gr Berger's so it's on at 250yds.

I think I got this one. Get a MIL/MOA scope, a .223, hunt behind a high fence, and sight in at 172 yards.

Was that right?

Almost. The .223 MUST BE an AR. Also, you don't need to sight in the rifle; just boresight it.

Sight them in to the distance you will be shooting 90% of the time. Then shoot them at other distances and learn your rifle and ammo

200.

My opinion....200 yards would be better if you are capable of grouping your shots in a consistent pattern. Nobody says they have to perfect bulls-eyes, but it cant be all over the place. Shooting at 200 (as opposed to 100) will make you better shooter and also gives a better indication of what ammo your rifle likes. With today's rifles, scopes, and ammunition, 100 yards is really holding back a lot of potential.

This will eventually make my head hurt.

Not a dig on the OP since I don't know him and there are always exceptions, but I usually get the feeling that most of the people who ask these types of questions aren't spending nearly as much time as they should at the range or at the ranch practicing. You can easily figure out the answers to all these questions with a little range time.

Personally, all of my rifles except rimfires are sighted in at 100 yards and I know exactly where they shoot at 200 yards and on out in 100 yard increments to the maximum practical distance for that particular setup. Could I get excited and miss a deer? Sure, but it won't be because I'm guessing at where to hold on him. It would just be because I made a bad shot. Happens every now and then, even when shooting targets.

I like 200 better because at the ranges I take 90% of my shots it eliminates having to think about where to hold. On some of my rifles I will sight them in at 3" high at 100 as long as the up/down "window" out to 300 or so is not too large. I "aim small" of course, but whether I hit the exact hair or 2" above/below it is not a concern of mine. I do not shoot at long/extreme range. The upshot is that the only time I have to think about hold is usually somewhere north of 325 or so depending on the rifle. 400 is as far as I will consider shooting. Although I have hunted big game for 40+ years,I am not big on "range time" so this method works best for me.