Laser Bore Sighter - Any good?

[Commando]

Bob I think your getting a bit confused mate. When you zero a rifle, you adjust the sights/scope and MOVE the MPI onto the correct zero position (CZP). The CZP will vary dependant on calibre and the distance you will expect to shoot at.

 

The CZP will give u shot placement in your kill zone over differing distance and allow you to engage inside these variables and your shot should be inside that kill zone. Faster calibre's/ammo will give a flatter trajectory over variable distance.

 

With a scope that has ballistic turrets you adjust the elevation drum to the given/estimated range to target. This should give you point of aim-point of impact at all ranges.

 

Bullets don't fly in an arc horizontally but are affected by variables such as wind.

 

When you zero, dependant on the range you zero at, the bullet will cross the line of sight in two places. These ranges will be dependant on the height of the scope above the barrel. For example if you correctly zero your rifle at 100yds, point of aim point of impact (point blank) you will also have point of aim point of impact at perhaps 30yds. If you know this, you can accurately use a laser bore sighter to 'check zero' at 30yds before you go shooting. We have all had the frustration of a poor shot due to loose scope mounts or knocking the scope.

 

The laser boresighter is not a replacement to zeroing but certainly a handy aid, for initially setting a rifle/scope up and checking zero.

 

The military use a similar system with a collimator. This is used to check zero before firing and also on operations. It is deemed accurate enough to be used in court as admissible evidence that a weapon was correctly zeroed.

 

👍Cdo

[Commando]

Matelot- Some good info and reviews here...

 

http://www.reloaderaddict.com/best-laser-bore-sighter-review/

[Duncansimpson]

I bought one this year (uttings were the cheapest) it cost around £40 and probably saved me a couple of rounds at most. If you are fitting sights all the time it would be useful but I doubt I'll ever use it again now I'm set up. Interestingly I put it back in once rifle was sighted and the laser was miles off centre. At least an inch at 25m!

[matelot]

I bought one this year (uttings were the cheapest) it cost around £40 and probably saved me a couple of rounds at most. If you are fitting sights all the time it would be useful but I doubt I'll ever use it again now I'm set up. Interestingly I put it back in once rifle was sighted and the laser was miles off centre. At least an inch at 25m!

 

Thanks for your comments everyone

 

Duncan, when you put the laser in do you find the laser is consistently an inch off in the same direction?

 

If it is surely it would make a good check that your scope is zeroed in?

[Bob The Dog]

Commando - yeah, the adjustments are made on the scope to bring the cross hairs to the point where the bullets are hitting the target, and then settings can be obtained for distances greater or lesser than the zero range. Bullets do fly in an arc horizontally when fired from a weapon with a rifled barrel. It's called spin drift. The bullet rotates and causes it to bend it's course, a bit like a curved football shot. Granted, it probably won't affect things hugely, but over distance, it can make the difference. Again, I would never trust a laser sight for accuracy of shot. There really is only one way to guarantee consistent shot placement, and unfortunately that will cost you a few quid! Cleaning regimes will also affect shot placement, as pressure within the barrel will be affected. Wet days, dry days, air pressure - it all has a bearing.

[Stubby]

And just to throw something irrelevant on the ranges you are talking .......If you you are firing long , ( Barrett 50 cal stuff ) The rotation of the earth will affect target position . If firing with the direction of rotation the target will drop from the point of aim . If firing against the rotation the target will lift from the point of aim .........

[Commando]

Bloody hell, the OP asked about whether laser boresighters were any good, and got a lesson in internal/external ballistics! Ha ha.

 

Spin drift and coriolis effect, I doubt they will come into effect at normal zeroing distances???

[Bob The Dog]

You're probably right cdo! I just worry that there'll be a poor set up and zero, and whatever is being aimed at will be missed, or worse, badly injured and has a slow death. Destruction of animals needs to be quick and clean, and that'll never happen if the set up and variables aren't all properly considered.