Bore sighter question

Depends on the bore sight. Almost all of the cheaper ones I have would have to be installed exactly the same way with no tolerance issue or inconsistencys vertically or horizontally. Most I’ve seen cannot do that.

I use an older Leupold Zero Point magnetic boresighter in this very manner:

https://www.leupold.com/gear-and-accessories/tools/zero-point-magnetic-illuminated-boresighter

Short Demo



It works like a charm for this purpose. I keep a binder with blown up sigther grids and the zeros recorded by rifle and load. When going on a hunt, I take a copy of that gridsheet with me and the boresighter just in case. It also makes it very easy if you have to remove and reinstall a scope. The precision really depends on the scope magnification, more zoom = more exact, but even with the low powered scopes it's always put me within a couple clicks.

The only issue I've found with it is with a rifle that doesn't have a square crown, IE a flashhider etc.

Unfortunately it looks like Leupold discontinued it, I honestly have no idea why. It's a great little tool.

Chuck

If you dropped the rifle and caused a shift, what makes you think there wasn't damage which will allow a subsequent shift?

Run a bolt into a nut. Put the nut over a hole. Hit the bolt with a hammer hard enough to make it slip... Not so different than what we're talking about with a zero shift caused by a drop.

Bore sight tools will only get your POI within 2"-3" of POA at about 50 yards. Even if this method worked it wouldn't guarantee the kind of zero I'd want. I've taken a few hard falls when hunting and hit the ground pretty hard with rifles. I've never had one lose zero and if it did something is broke or I'm using cheap optics. It isn't like I can just re zero the rifle and keep hunting. If I'm hunting more than an hour from home I carry a spare rifle. Never needed one yet.

I have yet to find a use for these tools. I can zero a bolt gun at 100 yards with 3 rounds of ammo in 5 minutes without one. Any other rifle type requires 4 rounds. I'd save the money and buy more ammo.

I use the Leupold Zero bore sighter a lot.

I do use it to visually check my zero before a day of shooting. I use it more though to adjust my scope for different loads. I tend to use 165 HPBT, 168 SMK, and 175 SMK through my Rem 700 5R. My baseline is the 165 grain load. The 168 SMK has a different point of impact. Let's just say it is down one square and over one square looking through the bore sighter at 200 yards. I have this differential in my rifle data book. So when I change the loads, on goes the bore sighter, and I adjust the scope. Then I loosen the turrets and zero them.

It works like a flippin' charm.

I've tried them and actually think the old look down the bore and adjust the scope works better. I go across the basement and put the rifle in the cleaning rest with bolt out pointing at an orange target on the wall. If its a slug gun i take the barrel off and look down the barrel and adjust the scope. semi auto i'm not sure as i usually just put a large piece of cardboard up at 25yards and fire one shot then chase the bullet.

If such happens, after 'bore sighting', IF one can safely manage, test fire the rifle at 25 yards. Bullet impact may be a bit high or low, but SHOUD be on for windage. Elevation will vary depending on long range zero. There are calculations for ranges depending on caliber, muzzle velocity, ballistic coefficient, distance of muzzle below line of sights and phase of moon, but one usually doesn't have all that information handy. Having windage on and elevation correct at 25 yards will give most common calibers fairly close hits at visual distances. (Not for 700 yard shots across the valley.)

So I have an inexpensive laser that fits into a cartridge case shaped adapter. I place an old red truck reflector out at the distance I'm interested in (usually 50 yds) and get the best reflection I can. That means the primary laser beam is not bouncing off the lands. Bring the scope to bear on that point. Then I'm usually on paper within 4" or so at 100 yds. Enough that I could "kill" something deer sized with that if I had to ... But I'd never hunt that way. I'd tighten it up on paper.

The issue for me is what happened to the rifle in the fall? Yeah, the scope got knocked loose... But what about the crown? Just a tiny ding in the crown and your laser POA is worthless. It might still be a consistent rifle, but will not be near laser point of aim ...

I look down the bore like other guys here... I took a little Maglite flashlight and taped a piece of cardboard over the entire lens with only a very small opening in the center. It will show you a pinpoint of light when pointed at you. I set this about 50 yards away and that's what I look at down the bore. Works fine even in bright sun. Been doing it this way for decades and it works just fine. And it's pretty close to free.

Maybe 2 shots to ensure you're on the paper at 50, then right out to 100 or whatever. It has never failed me.