100 yard zero

[grauhanen]

Doesn't the length of a barrel affect the bullet velocity?

Bullet velocity doesn't have a consistent relationship with barrel length. Two barrels the same length can yield different MVs for the same lot of .22LR match ammo.

In any case, barrel length is irrelevant when it comes to ballistics calculators or bullet trajectory. Once out of the muzzle it is what it is. The MV, whatever it may be, is one of the inputs put into the calculator. Ballistics calculator don't have or require an input for barrel length.

 

[Meroh]

That's a good reminder that ballistic charts show the trajectory - depending on certain conditions. Barrel length for one, and other things may very well add up to noticable differences from a chart.

Theory vs experience.

Very, very true; however one can "improve" rather than "reinvent" the wheel, and use an ammo manufacturers chart as a starting point from which to generate your personal dope.

 

[Tokay444]

If you're sighted in at 25 yards, you very nearly have a zero at 50. A ballistics calculator shows that a CCI SV round that's zeroed at 25 will be just over 1/2" low at 50 yards; a CCI Mini-mag 40 grain round will be about .15" low at 50. This is with a scope that is 1.5" above the center of the bore. That may be close enough for gophers.


Ballistics charts show how a trajectory should be when the bullet behaves according to known inputs such as MV, scope height above bore, and even wind and temperature. The barrel length is irrelevant. Why? Once a bullet leaves the muzzle it's flight is unaffected by the length of the bore it passed through on its way to flight.

With .22LR ballistics charts can't account for things that can't be given as an input. For example, any imperfection or irregularity in the bullet shape (particularly the heel, which is always unseen by the shooter), center of gravity, or weight usually remain unknown to the user but they can affect trajectory. Imperfections such as these are among the reasons for .22LR bullets not always behaving as ballistics calculators predict.

As for bore sighting at 100, next time anyone is shooting at 100 yards, take the bolt out of the rifle and look down the bore. A 8.5 X 11 paper wouldn't be all that easy to make the center of what is seen through the bore. Perhaps it can be done but it wouldn't necessarily be a simple thing. That's why a lot of .22LR shooters sight in at closer distances before moving to 100.

LOL. If a half inch is "very nearly zero", then you keep on keepin' on. We're on not in the same arena.

 

[grauhanen]

LOL. If a half inch is "very nearly zero", then you keep on keepin' on. We're on not in the same arena.

No, I guess we aren't in the same arena. Perhaps you have higher standards.

 

[Tokay444]

I at least want my zero to be zero. That's why there's truly only ever one.

 

[grauhanen]

I at least want my zero to be zero. That's why there's truly only ever one.

When a shooter shoots five rounds that are 1MOA at 50, which one of them represents the truly one zero?

 

[Tokay444]

When a shooter shoots five rounds that are 1MOA at 50, which one of them represents the truly one zero?

None of them if his zero isn't at 50 yards.

 

[grauhanen]

None of them if his zero isn't at 50 yards.

Assume that the shooter, like you, believes he's zeroed at 50.

 

[Tokay444]

Assume that the shooter, like you, believes he's zeroed at 50.

I don't zero at 50.

 

[grauhanen]

I don't zero at 50.

This is like pulling teeth that don't want out. At what distance do you zero your .22LR -- 25 yards?

 

[Tokay444]

This is like pulling teeth that don't want out. At what distance do you zero your .22LR -- 25 yards?

Zero at 25 yards. Dial your elevation for every other distance.

Reading is hard.

 

[22forever]

Wow! Who pissed in your corn flakes?

 

[Longstud]

If you have to make, “clicks” you’re not sighted in at 25 and 50.
There’s nothing voodoo about boresighting. I’m just calling bull#### on boresighting at 100 yards with a 22 and being on paper first shot, unless the berm is “paper”.

This just shows how little you know about rimfires. Both my competition guns are sighted at 50 yards and at 25 yards shoot 1/4" high which translates to 4 clicks down with an moa scope. 4 clicks at 100yards are 1" and 4 clicks at 50yards are 1/2" and 4 clicks at 25yards are 1/4". Simple enough that anyone should be able to follow but theres always exceptions. Not everyone needs to go to a range, some of us can shoot on our own property. I guess my idea of accuracy and yours are vastly different but hey 2 litre pop bottles are still fun.

 

[Longstud]

I at least want my zero to be zero. That's why there's truly only ever one.

NO actually theres two so once again your wrong. The hole just keeps getting deeper

 

[Tokay444]

lol.

 

[snooker]

Yup, 2 zeros.
Your bullet path crosses the line of sight twice. Two zeros.

 

[Tokay444]

Yup, 2 zeros.
Your bullet path crosses the line of sight twice. Two zeros.

While technically true, the one further along the trajectory is subject to atmospherics and is never truly zero. Same reason you don’t choose 100 yards as your primary zero.

 

[Meroh]

Well, that was a good. on topic discussion of "terminology", Now I will take it up a notch. In the winter, the outdoor range at our club is not always easily accessed due to snow. Therefore I zero at 20 yards; it is all we have indoors. When I go outside, I "dial up" to 100 yards, or farther as required. With the zero stop, 20 yards is the real zero. 50 is a slight hold-under 100 a 6 MOA dial up. (+- 1moa, depending on ammo)

 

[OkayShooter]

And you may have to zero at different clubs.

One club is open. I can zero Friday. Then goto another club Saturday for a shoot. That has baffles and side berms and narrower. My gun would be off a inch or two, because its like a wind tunnel.

 

[grauhanen]

LOL. If a half inch is "very nearly zero", then you keep on keepin' on. We're on not in the same arena.

You laughed when it was suggested that half-an-inch difference at 50 was "very nearly zero". You insist that only a zero obtained at closer distances such as 25 yards is "truly zero".

While technically true, the one further along the trajectory is subject to atmospherics and is never truly zero. Same reason you don’t choose 100 yards as your primary zero.

You say that it's only a technical triviality that there are two zeros in a bullet's trajectory, that the further supposed zero is never truly a zero.

That's not correct.

It's quite possible to truly zero at longer distances. In the different arena you say you're in, whatever you think it may be, you must understand that the "atmospherics" affect trajectories at every distance. At closer ones such as 25 yards they are still there but are simply less obvious.