Need help

[Beekeeper]

OK heres the senerio.
Old man, had cataract surgery , still have trouble with iron sights.
Mostly impatience I guess!
Decided to try hand at scopes, using not mounting.
Bought one of the BSA old style boresighters from a friend.
You know the kind with all the spuds and the optical thingy on the end.
Look through the scope and see the grid, lineup the crosshairs and you are supposed to be on at 25 yards.
Says the squares are each 4 inches so how much rise do you give ( how many sguares) to bring it reasonably on at 100 yards, 200 yards?

No data supplied with unit and BSA only says 25 yards.

Any one got any ideas or data they will share or is this some more of the voo-doo that only Master gunsmiths are privilage to!



beekeeper

[oneokie]

Not a gunsmith, but if your scope centerline is the standard ~1.5" above the bore centerline, you should be reasonably close using the 25 yd zero at 100. The boolit is rising when it gets to 25 yds and will continue to rise for some distance beyond before it starts dropping. (depends on velocity and boolit weight)

[Bren R.]

The easiest way would be to go out in stages... sit down on a bench rest - use the collimator at 25 yards, fire a few (take the collimator out!)... move the target out to 50, fire a few... out to 75, fire a few... out to 100, fire a few... adjusting as you go if necessary.

Then always final sight-in offhand on your hind legs to account for that one leg shorter than the other, or that bend in your neck from the time you slept out in the rain... whatever your body has that the sandbag doesn't. :razz:

Bren R.

[gandydancer]

get you rifle punching holes in the center at 25 yards then try 50 yrds & adjust as needed out to 100 yards. or get you rifle punching holes in the center at 25 yrds and set your cross hairs 2" high at 25 yards on your target and then try 100 yards. you should be close. GD

[Wolfer]

I've found with most modern guns with jacketed when I get them dead on @ 200 most are dead on @ 40 yds

[scrapcan]

one can look up point blank range and get a good idea of where you can sight in close to get you on out to Point blank range for your cartridge at normal jacketed velocities with standard bullet weights.

Since you are on the cast boolit forum, you probably already know that the trajectory tables mean naught if they are not for the cast boolit you are shooting.

[CATS]

Don't forget that some scopes take a few or a "more than few" shots to settle in any time that you change the zero. So that means that you get to shoot more just to be sure that it hits where you aim.

[Wolfer]

On bolt guns I take the bolt out. Set the rifle into the sandbags pretty good and without touching the gun look through the bore and line it up with something far away. Then without touching the gun look through the scope. Then adjust till their both looking at the same place. This won't be dead on but it will be on the paper usually.

The scope will adjust backwards as you are moving the scope to the boreline instead of the bullet to the scope line

[Jim]

On bolt guns I take the bolt out. Set the rifle into the sandbags pretty good and without touching the gun look through the bore and line it up with something far away. Then without touching the gun look through the scope. Then adjust till their both looking at the same place. This won't be dead on but it will be on the paper usually.

The scope will adjust backwards as you are moving the scope to the boreline instead of the bullet to the scope line

Been usin' that procedure for many years. Saves a lot of ammo, time and "Where th' heck is it hittin?".

[Bren R.]

Don't forget that some scopes take a few or a "more than few" shots to settle in any time that you change the zero. So that means that you get to shoot more just to be sure that it hits where you aim.
And also, go past the mark you want and come back to it. That is... if you need to go 12 clicks left... go 17 and come back 5. I've always given the scope a sharp rap after changing zero as well to "set it".

Bren R.

[looseprojectile]

one of the 30 caliber mirrors that fit in the chamber to boresight machine guns. Stole it from the US Navy.
Don't know where it went. I still use a small mirror in closed breech guns and just look through the bore on guns with a bolt or removeable breech to boresight them.

Also, when you shoot any gun the boolit/bullet never rises, it starts to fall the instant it leaves the barrel. Adjusting the sights so the boolit hits the target while it is falling is the plan.
Most times it is easier to shoot at very close range and adjust while increasing the range. I get to do a lot more shooting this way.


Life is good