bore laser sighting

[wittmeba]

I'm trying to learn about bore laser sighting. I want to sight my S&W .40 and my .308 bolt action rifle with its scope.

Can you see them at all during daylight hours?

Pistol and rifle:
Does a bore sight have a polarity (up/down/left/right). It being round if it happens to point high by 1" or so at 10 yards can you mark the sight and rotate it in the cylinder 180° reinsert into the chamber and retest?

Rifle:
Is it appropriate to sight the rifle at some shorter distance (25 yards) and use the moa to zero for 100/200 yards?

Are there a single bore sights that might fit a 9MM and .40 cal?

[MarcSpaz]

I have used bore lasers before. They are mostly designed the same, but there are several types. I have never seen one that had orientation that was adjustable though.

They basically all suck... The concept is good, but the only real purpose I could find is to generally get the scope in the right direction at no more than 25 yards. And more-so windage than elevation. In well light areas, the lasers I have used all maxed out at 20-25 yards with the exception of one that was about $130 and used a green laser.

My honest opinion is, save the money and just zero the weapons via live fire. A few bullets are a lot cheaper than a quality bore laser sight.

[skeeterss0]

I think the purpose of the bore laser is to get you on paper at 25 yds.........any finer adjustment needs to be done on the range.

[FiremanBob]

With respect to your second question, you can definitely sight in at a smaller distance and know that you are also zeroed at a longer one. There are two zero points in a bullet's trajectory. At the near zero, the bullet is still rising because the sight is adjusted to compensate for the height of the sights above the bore. The bullet continues to rise for a distance, then naturally falls and the far zero is where the bullet's path crosses the line of sight on the way down towards the ground. In between, the highest point of the bullet's trajectory is called the maximum ordinate.

For example, a standard AR with iron sights can be near-zeroed at 25 yards to give a far zero of 325 yards.

The actual trajectory including near-zero, maximum ordinate and far zero depend on:

The height of the sights above the bore;
The muzzle velocity of the load;
The ballistic coefficient of the bullet.

The closer your near-zero, the higher the arc that the bullet will make and far-zero will be at a greater distance. The farther out your near-zero is, the flatter your trajectory, with a closer far-zero point.

[wittmeba]

Thanks for the comments and thorough explanation. I do understand the flight path of the bullet and why there are two points of intersection of the sight line.

I will likely avoid them as this seems the general consensus on value but I thought it might be fun to tinker with them. Without a sight pusher for the pistol it would be useless.

[AlanM]

Most bore sighters that fit the muzzle have different, changeable, plugs for .17 up to .50 cal.
I've checked my .22, 9mm, .40, and .45 with the same unit. (mostly to insure side to side alignment).
Iv'e used this sighter on my .22lr CZ452 out to 50 yards on a cloudy evening with no problem.

I have a 7.64x54R laser sighter for my Mosin-Nagant that I haven't used yet. It's actually fits the chamber and points, literally, down the centerline of the bore.

OBTW - both units are red light.

If you want to check to see if the sighter is off do what I did.
I installed it on my CZ452 and aligned and zeroed my scope on the dot.
I then rotated the sighter 180 degrees and checked again.
The scope was still on the dot, so I know the sighter is pointing concentric with the center of the barrel.

[jdonovan]

I've never found a factory pistol that needed sight adjustments. Found plenty of shooters who needed adjustment, but the sights were just fine =).

I've got a magnetic one that sticks to the muzzle of the firearm. I find the bore laser bore sight tools are a great way to get on paper at 25 yds the very first shot. It has easily saved me its cost in ammo.

But that depends a lot on how many scopes you mount etc....

[Ironbear]

Bolt actions aren't too bad to get on target if you have a bench and sandbags or a rest/vice, since you can remove the bolt and look down the bore!

Put a round target out at 25 yards, pull the bolt out and look down the bore and adjust the rifle up so that the target is lined up with the bore. Then with the rifle held still, adjust the scope to match. That should have you on paper.

Then take one shot at the target, and with the sandbags lock the rifle in place pointing to the same point of aim. Keeping the rifle still, adjust the scope to where the hole in the paper is. At that point, depending on how steady you were able to keep things, you should be pretty close to zero'ed at 25 yards.

From there on it is just a matter of figuring out what over-under you really want and fine-tuning it.

The visual bore sighting works surprisingly well, because your eye is pretty good at aligning the concentric circles of the bore and the target; similar to an aperture sight.

[MarcSpaz]

It has easily saved me its cost in ammo.

But that depends a lot on how many scopes you mount etc....

I would think that the expense of ammo would play into it as well. All of mine were used in 308 and 556. $120-$130 for the quality magnetic unit turned out to be a massive waste for me. Comparatively, if I was sending $7 projectiles down range, I may have been more prone to keep it. LOL

[jdonovan]

you also use an indoor range, when you have the option to put the first target at 5yds, to ensure on-target. You get to an outdoor range with fixed target points, sometimes with the 'rifle' side of the range having nothing closer than 50yds. And there were a few days I saw people shot 2-3 boxes and never found the paper.

[MarcSpaz]

Wow... that stinks. Yea, I could see a benefit there.