Question of the Day - WHY Zero at 100yards

[GunnyUSMC]

I was doing some ELR stuff this weekend and Mike, the person coaching us, asked the question "WHY DO YOU ZERO AT 100 YARDS?"

We were a bit puzzled with the question because it was the norm that everyone followed.

Well, Mike went on to say that it was likely because back in the day, the most common range for hunting was limited to 100yards because their guns, with some exceptions, didnt shoot well at longer ranges.

Mike went on to share that with today's bullets and advanced ballistics that goes into making them, many of those bullets do not stabilize until after 100yards. For that reason, he said he gets tighter groups at 200 vs 100 yards so that is where he sets his zero.

Interested in thoughts from others???

 

[Ruff 364]

Because your line of sight through the optic and your bullet flight path tend to coincide at that distance. The environmental effects are also have less of an impact at the closer ranges.

 

[rustyinbend]

Sorry ... but from a "physics" standpoint, I'm not buying the concept that an "unstable" round going by 100 yards, magically "stabilizes" before 200 yards. If it's wobbling at 100, it'll be wobbling more at 200. I'm just sayin' ...

 

[jb0311]

Mike who?

 

[rustyinbend]

Mike who?

It's "Mike". You know ... Mike. The guy that said all that stuff. You don't know Mike? How the heck do you not know Mike.

 

[MadDuner]

100yds seems to be a convenient distance to start with.
Pick a distance - then add or subtract Mils or MOAs from there.
It's your own dope.
If I was you, I'd start with 162.5 yds and have some fun with it.

 

[Baron23]

Sorry ... but from a "physics" standpoint, I'm not buying the concept that an "unstable" round going by 100 yards, magically "stabilizes" before 200 yards. If it's wobbling at 100, it'll be wobbling more at 200. I'm just sayin' ...

Yeah, that one has me scratching my head also.

 

[OREGUN]

Classic Mike. That guy is always looking to subvert the dominant paradigm.

 

[reelserious]

it is done so at most normal human distances like 0-1000 yards you are always dialing up to get your elevation correct. Also easy to remember and most ranges have a 100 yard distance to check zero. ELR it makes sense to go for a different zero but for 99% of the time 100 works great.

 

[rustyinbend]

it is done so at most normal human distances like 0-1000 yards you are always dialing up to get your elevation correct. Also easy to remember and most ranges have a 100 yard distance to check zero. ELR it makes sense to go for a different zero but for 99% of the time 100 works great.

Agree 100% ... well ... maybe 99%. I routinely shoot out to a mile using 100-yard zero's for 300-WM, 300-PRC, and 300-NM. Maybe that's not "ELR" ... but it sure as f**k feels like it is to my old eyes and sore back.

 

[reelserious]

I have numerous 1000 yard rifles all zeroed at 100 yards. I have one rifle that I shoot out to 1 mile and I have that at 600 yard zero. Just makes it out to a mile with that set up and scope/reticle

 

[SortOfClear]

1) 100 yards/meters/whatever-minimal environmental effects due to short time of flight to minimize variables

2) Far enough to identify human input error but close enough to be repeatable results with fundamentals executed well
(Useful data)

3) bullet trajectory stays below line of sight thru entire trajectory until bullet is overcome by gravity (very useful in certain types of shots). The antithesis of this is a battlefield zero (or max point blank zero) of a rifle where the bullet rises above line of sight, then dips below line of sight at two different ranges.

 

[Taylorbok]

3) bullet trajectory stays below line of sight thru entire trajectory until bullet is overcome by gravity (very useful in certain types of shots).

This is why you zero at 100.

Also Mike has made it apparent he doesn't understand bullet flight, I wouldn't listen to that guy anymore.

 

[lash]

Sorry ... but from a "physics" standpoint, I'm not buying the concept that an "unstable" round going by 100 yards, magically "stabilizes" before 200 yards. If it's wobbling at 100, it'll be wobbling more at 200. I'm just sayin' ...

This used to be covered almost monthly on old SH under the Fudd lore of the bullet ‘going to sleep’.

ETA: this was disproven and squashed back then pretty often.

For the OP, you should ask ‘Mike’ to show you where this is written and proven. Or is ‘Mike’ smarter than every ballistician ever published?

 

[rustyinbend]

This used to be covered almost monthly on old SH under the Fudd lore of the bullet ‘going to sleep’.

It's like it goes by the 100-yard marker and says ... "Oh shit, I'm supposed to be stable. I'd better get on that." Then after successfully going by 200-yards with great and new-found stability, it smiles with satisfaction and says ... "Now I'm ready to make the rest of the trip out to a mile."

Um ... I don't think so.

 

[MadDuner]

This used to be covered almost monthly on old SH under the Fudd lore of the bullet ‘going to sleep’.

ETA: this was disproven and squashed back then pretty often.

For the OP, you should ask ‘Mike’ to show you where this is written and proven. Or is ‘Mike’ smarter than every ballistician ever published?

Is there a compiled book of Fudd lore that can be acquired?
I need to be sure I'm doing it right.

 

[lash]

On the positive side, as already mentioned, it is perfectly acceptable to zero a rifle only used for ELR shooting(1500yds/meters plus), if you have device (rail, rings, mount) that allows you to use the addition elevation in your scope. Otherwise it’s just a waste and you’re kidding yourself

 

[lash]

Is there a compiled book of Fudd lore that can be acquired?
I need to be sure I'm doing it right.

that would be a fun booklet to write and read.

 

[Mike Casselton]

It's "Mike". You know ... Mike. The guy that said all that stuff. You don't know Mike? How the heck do you not know Mike.

I swear to God it wasn't me.
I'm not in SC and haven't been for at least four years, maybe more. I have no reason to even go through there again.

But yeah, those Mike guys. Sheesh!!

 

[GunnyUSMC]

Love the responses...

You are a tough crowd. Didn't expect anything less...

3) bullet trajectory stays below line of sight thru entire trajectory until bullet is overcome by gravity (very useful in certain types of shots). The antithesis of this is a battlefield zero (or max point blank zero) of a rifle where the bullet rises above line of sight, then dips below line of sight at two different ranges.

Referring to near/far zero (50/200)?

 

[Taylorbok]

It's like it goes by the 100-yard marker and says ... "Oh shit, I'm supposed to be stable. I'd better get on that." Then after successfully going by 200-yards with great and new-found stability, it smiles with satisfaction and says ... "Now I'm ready to make the rest of the trip out to a mile."

Um ... I don't think so.

And at the same time says "Oh shit I deviated from the other bullets, I better get back over there."

On the positive side, as already mentioned, it is perfectly acceptable to zero a rifle only used for ELR shooting(1500yds/meters plus), if you have device (rail, rings, mount) that allows you to use the addition elevation in your scope. Otherwise it’s just a waste and you’re kidding yourself

In theory that would be fine if that's the closest target you ever shoot but in reality most ELR matches start at 800-1000 and go out from there.

 

[canezach]

That myth of "bullets aren't stabilized until after 100 yards" has been disproved for a while now and "tighter groups at 200" is bullshit. I remember reading that crap years ago about the "bullet going to sleep" or something ridiculous. I would find a new coach

 

[lash]

Love the responses...

You are a tough crowd. Didn't expect anything less...

Referring to near/far zero (50/200)?

Correct.

 

[lash]

In theory that would be fine if that's the closest target you ever shoot but in reality most ELR matches start at 800-1000 and go out from there.

That is correct and I should have been clearer. When I said (1500 yards plus) I meant that is what I consider to be ELR ranges, not the zero for the rifle. I consider under 1500 yards/meters to just be Long Range. You can attend regular PRS/NRL matches just about anywhere that have at least one stage in the 1000-1500 yard range.

 

[isofahunter]

Please give to Mike to explain stability

 

[rustyinbend]

That myth of "bullets aren't stabilized until after 100 yards" has been disproved for a while now and "tighter groups at 200" is bullshit. I remember reading that crap years ago about the "bullet going to sleep" or something ridiculous. I would find a new coach

Maybe Mike is an excellent golfer, and the coaching relationship can be salvaged.

 

[david walter]

I zero at 100 at the range for reasons stated by others (minimal environmental impacts, etc.)

All my dope baselines off of a 100 yard zero for center fire rifles.

22LR at 50 yards.

 

[jb0311]

Is there a compiled book of Fudd lore that can be acquired?
I need to be sure I'm doing it right.

We need a thread just dedicated to the shit people hear at classes from some of these guys. There's been more than a few head scratching bits of "advice" shared on here over the years. Especially from some of the ex-military and LEO instructors who lean heavily into those titles to attract new students that don't know any better.

 

[rustyinbend]

Seriously though ... I use 100 yards for three reasons ... (1) fewer variables like wind and angle and humidity and (blah blah blah), (2) I have 20-MOA rails and 30-MOA scope rings on all of my distance rifles and I use Leupold Mark5HD scopes that have a ton of up-clicks available, and (3) I'm lazy and don't want to walk 200 yards to place and retrieve my targets.

 

[rustyinbend]

We need a thread just dedicated to the shit people hear at classes from some of these guys. There's been more than a few head scratching bits of "advice" shared on here over the years. Especially from some of the ex-military and LEO instructors who lean heavily into those titles to attract new students that don't know any better.

Hey ... whose military titles are you talking smack about? LOL

 

[Bacarrat]

I would ask for a refund. This Mike guy sound like he is full of shit.

And I think Bryan Litz or someone else has a challenge on if anyone could prove the whole the bullet is more stable at XXX yard then 100 yards.

 

[jb0311]

Hey ... whose military titles are you talking smack about? LOL

I just assume they are all 2nd Lts and it makes more sense in my head.

 

[rustyinbend]

I just assume they are all 2nd Lts and it makes more sense in my head.

Old joke ...
Q: What's the difference between a 2nd Lieutenant and a PFC?
A: The PFC has been promoted once.

 

[ACard]

Old joke ...
Q: What's the difference between a 2nd Lieutenant and a PFC?
A: The PFC has been promoted once.

Also dont forget the PFC wont get you lost in a land nav course

 

[Dogtown]

“I’m not trusting PFC Suffy to shoot a back-azimuth to resect and find our location…get the LT!”

 

[sirhrmechanic]

Wow… “bullet going to sleep” in post 1!

The reason you zero at 100 is because it takes 100 yards to achieve its full spin rate…

The barrel just starts it spinning, but Newtonian physics proves that it won’t be fully spinning until after 100 yards, then it gradually slows down until it goes to sleep.

I can run the formulas here… but it’s hard to type calculus and fractal geometry on a phone.

Cheers, Sirhr

 

[rustyinbend]

Wow… “bullet going to sleep” in post 1!

The reason you zero at 100 is because it takes 100 yards to achieve its full spin rate…

The barrel just starts it spinning, but Newtonian physics proves that it won’t be fully spinning until after 100 yards, then it gradually slows down until it goes to sleep.

I can run the formulas here… but it’s hard to type calculus and fractal geometry on a phone.

Cheers, Sirhr

Yes ... please explain to us non-believers how a bullet spinning at a specific rate, and on a particular trajectory ... speeds up the spin "after" it leaves the barrel. What force amplifies the spin and stability (a) after it's left the barrel, and (b) over time when atmospheric forces are doing nothing but "degrade" that spin and trajectory. I don't understand how the fastest spin, and truest trajectory, aren't at the exact point where it leaves the safety and stability of the barrel.

 

[jb0311]

Yes ... please explain to us non-believers how a bullet spinning at a specific rate, and on a particular trajectory ... speeds up the spin "after" it leaves the barrel. What force amplifies the spin and stability (a) after it's left the barrel, and (b) over time when atmospheric forces are doing nothing but "degrade" that spin and trajectory. I don't understand how the fastest spin, and truest trajectory, aren't at the exact point where it leaves the safety and stability of the barrel.

Pretty sure he's joking. Right?

 

[OREGUN]

Yes ... please explain to us non-believers how a bullet spinning at a specific rate, and on a particular trajectory ... speeds up the spin "after" it leaves the barrel. What force amplifies the spin and stability (a) after it's left the barrel, and (b) over time when atmospheric forces are doing nothing but "degrade" that spin and trajectory. I don't understand how the fastest spin, and truest trajectory, aren't at the exact point where it leaves the safety and stability of the barrel.

C’mon Rusty.

 

[rustyinbend]

C’mon Rusty.

C'mon What ??? I'm honestly struggling with this idea that spin increases and stability improves "after" the projectile leaves the barrel. It's like spinning that top in the photo above, and saying that after the hand leave the top ... it'll spin faster and be more stable. I'm not a physicist so if someone is saying that, I'd love to understand why.

 

[sirhrmechanic]

Pretty sure he's joking. Right?

It’s sooo simple!

Sirhr

PS. Ya think?

 

[OREGUN]

C'mon What ??? I'm honestly struggling with this idea that spin increases and stability improves "after" the projectile leaves the barrel. It's like spinning that top in the photo above, and saying that after the hand leave the top ... it'll spin faster and be more stable. I'm not a physicist so if someone is saying that, I'd love to understand why.

He’s joking bud.

 

[sirhrmechanic]

He’s joking bud.

Sirhr

 

[Tokay444]

Don’t give Mike anymore more money, and ask if he gives you back the money you’ve already given him, if you’ll automatically forget everything he’s said.

 

[Aftermath]

Here's the real deal.

If you are a hunter and want to have a quick to aim without much thought rifle, determine an acceptable point blank zero and zero there. For example, I have a 280Ackley that I have zeroed at 272 yards. With that zero, the bullet is high of my line of site by 3" about 175 yards and low of my line of sight at about 350 yards. I do have the exact rise/drop, along with yardages for 3 different zoom levels of that second focal plane scope taped to the stock for easy reference in case I can take more time or want to venture a guess.

If you are more of a target shooter, or a hunter that can afford to take more time setting up for the shot, then zero at 100 and dial. For example, I have a 300WINMAG zeroed at 100 yards. I can use my laser range finder to determine a pretty precise distance to the target. I can use my Kestrel to determine the wind, at least where I am at that moment and I can use my ballistic solver to determine how much to dial my scope for both. This rifle also has DOPE taped to the stock.

 

[jb0311]

PS. Ya think?

I don't give people credit anymore so to answer your question, 50/50 on you being serious. Much dumber things have been said with much greater certainty. Use your sarcasm font next time.

 

[Aftermath]

I was doing some ELR stuff this weekend and Mike, the person coaching us, asked the question "WHY DO YOU ZERO AT 100 YARDS?"

We were a bit puzzled with the question because it was the norm that everyone followed.

Well, Mike went on to say that it was likely because back in the day, the most common range for hunting was limited to 100yards because their guns, with some exceptions, didnt shoot well at longer ranges.

Mike went on to share that with today's bullets and advanced ballistics that goes into making them, many of those bullets do not stabilize until after 100yards. For that reason, he said he gets tighter groups at 200 vs 100 yards so that is where he sets his zero.

Interested in thoughts from others???

Mike is a retard

 

[FredHammer]

If one does not have access to 100yds, they can shoot at 50 yards and make sure the point of impact at 50 yards corresponds with a 100yd zero. For example shooting a 308 Win would require the impact at 50yds to be .9” low.

 

[Bender]

I was doing some ELR stuff this weekend and Mike, the person coaching us, asked the question "WHY DO YOU ZERO AT 100 YARDS?"

We were a bit puzzled with the question because it was the norm that everyone followed.

Well, Mike went on to say that it was likely because back in the day, the most common range for hunting was limited to 100yards because their guns, with some exceptions, didnt shoot well at longer ranges.

Mike went on to share that with today's bullets and advanced ballistics that goes into making them, many of those bullets do not stabilize until after 100yards. For that reason, he said he gets tighter groups at 200 vs 100 yards so that is where he sets his zero.

Interested in thoughts from others???

I smelled this post all the way from over here. The universe called me here.

 

[jolofree]

I'm going to sleep reading these bullet bedtime stories Again
Unless said projectile is rocket propelled, maybe like an old TOW missile, nothing will happen to enhance/improve performance.
It looses velocity, looses RPMs & gyroscopic stability deteriorates, and it begins to drop/fall to earth, the Instant it leaves the muzzle. Understandably the increments are very small at short range and increase as range increases.
All undeniable laws of physics. Regardless what your LGS expert says