Okay, let's discuss this aforementioned topic.

Living near a huge urban area, most indoor ranges I can use are limited to 25 yards, which is not meters. 25 meters is 27.34 yards. I read in other posts here that one should zero the POI to be 1.25" below the POA at 25 yards, to account for the disparity. This is for M193. Once I finally get done building all my rifles & carbines, the only rifle I will have with a 1:12 twist will be the 604. All the rest (603, 649, 705, 727, 921HB and 945) will have 1:7.

Should this be the same POI/POA for M855, or even Mark 262 Mod 0? I wish to be as accurate when doing initial zeros as possible, given middle-aged eyes, and/or slightly worn barrels.

So what does the hive agree upon?

25 yards or Meters, not much difference.  Point of impact 1 inch low will get you on a GI E-type silhouette at 250-300 yards/Meters.  Not a precision hit.

Technically, the "1.25 inch below POA" technique was using a 1000-inch target, so not really 25 yards or meters (~27.8 yds or 25.4 m).  It was never intended to be a precision zero, particularly since it will change slightly with each lot of ammo, even if you stick to one supplier.

I can't say I've done a serious comparison between different 55gr loads on the 1000-inch target, but it should get you on paper.  Beyond that...you'll have to shoot it to verify it!

The ammo, in and of itself, being a few MOA at least, will make more of a difference than 25m vs. 25y.

I don't think it really matters much.  You will be zeroed at approximately 25 yards and approximately 300 yards.  Everything in between will shoot higher.

I zeroed at 25 meters and at 200 yards it shoots about a foot above POA.  So if you're aiming at a person aim for center of mass at any range and you've got 'em nailed.

Steve

A little low at 25 yards would probably be a good thing.  But as other say, you have to test what each set up is going to do at further distance.  A lot of us just zero at 50.  But if you can't.  Just do a little low (approx 1-1.5" at 25 and you'll have a close to 200 yard zero.  

But that would suck if you can't find an outdoor range to shoot at 100 or 200.  Isn't there any around?  I just saw you live in Illinois.  If you are interested in coming up to SE Wisconsin to join an outdoor range,  IM me and we can talk.  I'm not sure where to tell you to go in Illinois though.  I would think if you live in lower Illinois somebody has got a farm somewhere you could shoot on......

JJREA,

I am near the I-294 toll road. I can get to WI easily, but I cannot afford to shoot often, hence my firearms are mostly safe queens. Perhaps once I get everything done, we can arrange a zeroing day at your range. Another idea would be a retro rifle match (or a retro class within an overall military rifle match) patterned after a military competition. If you only have 200 yards available, targets can be scaled down to represent longer distances. That should prove to be a good, friendly competition for folks of all ages.

My range puts on those kinds of comps.  I shot a Garand match one time there.  200 yards.  Our range goes all the way out to 600.  The Garand matches will allow anybody to shoot whatever in the spirit of friendliness.  It's just the scores don't get sent to the CMP if you're not using an approved gun for that type of match, or something like that.  But they do HiPower matches and Long range scoped, is that F class?  Etc etc.  

But yeah, if you want to zero at 25 or 50 and shoot at 100 or even longer distances, let me know.  Would be fun.  FWIW, my Dad and Grandma live in Spring Grove.   And then others on my Dad's side of the family are in IL. Waukegan, Greys Lake, etc.  So I'm not anti Illinois people.    In fact I'm even a Bears fan.  Not rabid though.  How can you be?  LOL.

If you don't want to wait for me, you can always go to Bristol Gun Club off of 45 and C.  Very close to the border.  But the downside is they only allow 1 round in the gun at a time.  Blaaaaaaa.  100 yard max.   There is also McMiller in East Troy, WI.  Would be a much farther hike for you but they go all the way out to 300 there.  But more strict on shooting positions.  The 100 yard range only allow bench sitting and Standing.

JJREA,

I will PM you later this week. I am WAY out in the future for zeroing my rifles and carbines. I just want to see what I need to learn more about to ensure accurate zeros.

Now Maybe, just maybe, you might be able to set up an ARF.com Retro Three Gun Match, or just an NRA-type Retro Only match. Could be an idea to run past your club "elders" to see what the would wish to do and handle.

Personally, that Retro 3-gun would be cool, but I would need to get a retro shotgun ASAP. I can slap together a retro 603, but with an A2 lower for now.

Else maybe set up a postal match, meaning set a course of fire at 25 yards (or whatever), then folks mail in their targets (certified by someone else as properly doing the course), along with $2.00 per target set. Top Three get a small plaque, and all shooters get immortalized on a sticky post here each year.

I hadn't thought about twist rate with regard to zeroing, how would a 1:9 differ from a 1:12 in this regard?

Sounds good.  Let me know when you're ready.  I'll look into if they do a "retro AR" type shoot yet.