Bore sighting

[5wixy]

Another sniper and I had to show to the rest of the infantry sergeants course guys how snipers communicate and take shots.
We didnt have time to zero it properly so we decided to bore sight it straight to the target which was 500m.
From what I learnt about exterior ballistics is that a bullet never goes straight but in a curve. So me and the other guy discussed it and I said that it won't be close to the target and he said it will hit because the barrel is on target.
Well it was right on target and im not sure why and it seems to me like the bullet has a straight path.
Explanations are welcome.

 

[longgunJR]

Something great is about to unfold here... tagging for great knowledge.

 

[Alabusa]

I'm in....

 

[atepointer]

Who really zeros a rifle these days that's so 2018. It's all boar citing these days with the secret new ammo some of us have. Sounds like your buddy has some too.

 

[Bradu]

So you have time to teach others but no time to zero? I'm not going to touch on the other part...

 

[atepointer]

So you have time to teach others but no time to zero? I'm not going to touch on the other part...

He's a 'sniper' back off!

 

[alpine44]

Optical axis: A straight line that goes from your scope/irons to the target you see in the crosshairs/irons.

Bore axis: A straight line that goes through the center of your bore.

Bullet path: A parabolic curve that originates at the muzzle. I initially, the bullet path (almost) coincides with the bore axis but as distance increases, the bullet drops away from the bore axis due to the gravitational field on this planet.

To make the bullet impact the point of aim at distance, we need to tilt the optical axis towards the bore axis. When we then aim at a distant target, the optical axis will intersect the bulls-eye but the bore axis will intersect the target plane above the bulls-eye.

As the bullet leaves the barrel, it will be below the optical axis. At some point it will intersect the optical axis for the first time (first zero), then be over the optical axis for a while, and finally intersect the optical axis at the point the rifle is sighted in for (second zero).

I think you guys got lucky by really bore sighting over the target but not realizing it. Especially when the sun shines it is not that easy to eyeball the bore center.

If you need to bore sight you should do it at the first zero according to your ballistic data. I have a tennis ball hanging in a tree about 25 yards from my shop vise. That will get every rifle's first shot on a coaster @100.

 

[longgunJR]

For the bullet to travel in a straight path and hit a target at 500y with an non zeroed rifle he must have been shooting a .308, that's why snipers shoot that caliber. best there is period!...

 

[5wixy]

Optical axis: A straight line that goes from your scope/irons to the target you see in the crosshairs/irons.

Bore axis: A straight line that goes through the center of your bore.

Bullet path: A parabolic curve that originates at the muzzle. I initially, the bullet path (almost) coincides with the bore axis but as distance increases, the bullet drops away from the bore axis due to the gravitational field on this planet.

To make the bullet impact the point of aim at distance, we need to tilt the optical axis towards the bore axis. When we then aim at a distant target, the optical axis will intersect the bulls-eye but the bore axis will intersect the target plane above the bulls-eye.

As the bullet leaves the barrel, it will be below the optical axis. At some point it will intersect the optical axis for the first time (first zero), then be over the optical axis for a while, and finally intersect the optical axis at the point the rifle is sighted in for (second zero).

I think you guys got lucky by really bore sighting over the target but not realizing it. Especially when the sun shines it is not that easy to eyeball the bore center.

If you need to bore sight you should do it at the first zero according to your ballistic data. I have a tennis ball hanging in a tree about 25 yards from my shop vise. That will get every rifle's first shot on a coaster @100.

Thanks for the serious answer, usually we would bore sight on a fist sized object from 50 meters.

As for the other dumbasses, we had no time to zero in properly because we showcased different weapons. Negev light machine-gun, FN MAG, mk19,m24 sws, m72a9 law, so the hits werent important.
Please have a life

 

[2aBaC̶a̶]

As stated above bore zero at 100 and bore zero at 500 are on the same horizontal line. Visually.

I imagine you still had to dial the dope to hit at 500.

 

[Bradu]

 

[IronmanDaremo]

Physically impossible to use only bore sighting at 500m and make the shot with no other adjustments. Physics doesn't work that way. The bullet starts to drop the second it leaves the barrel.

You'd have to hold a good bit above target. Unless you had a scope on there that was somehow perfectly dialed for that elevation without having to do anything else. i.e. - pure luck the glass was already off the exact amount you'd need for a 500m shot.

 

[spife7980]

 

[2aBaC̶a̶]

Makes perfect sense.

 

[ShadowBear]

I don't know- I'm still back on "Another sniper and I " apparently with no knowledge of ballistics. Or, did they eliminate that from qualification?

 

[atepointer]

Thanks for the serious answer, usually we would bore sight on a fist sized object from 50 meters.

As for the other dumbasses, we had no time to zero in properly because we showcased different weapons. Negev light machine-gun, FN MAG, mk19,m24 sws, m72a9 law, so the hits werent important.
Please have a life

If hits were not important why spend time bore sighting? Are you and your buddy by chance doing any civilian courses? I have level 12 Omega-tactical super 2x secret clearance and can bring some of that new ammo.

 

[Dthomas3523]

@TheGerman

 

[TheGerman]

So please, do go into detail as to your military and sniper experience.

Also, we usually require a picture of (can block out your face) you in what you're wearing while you're out doing sniper things.

 

[AIAW]

View attachment 7205640

Holy shit that's the same SPERM mount I use!

 

[spife7980]

Holy shit that's the same mount I use!

 

[AIAW]

View attachment 7205794

Oh my.... setup perfect for Grimace.

 

[TheGerman]

So what happened to our snipery friend?

 

[ShadowBear]

So please, do go into detail as to your military and sniper experience.

Also, we usually require a picture of (can block out your face) you in what you're wearing while you're out doing sniper things.

Me? Usually rocking a little hot pink lacey number with a plunging bodice and thong undies, 6" spikes. You REALLY want a picture of that?

 

[isofahunter]

So what happened to our snipery friend?

Secret Squirrel Squad was called up he had to go.