Bore sighters?

[M77RMKII]

I found out the hard way that my rifle was out of whack, 6.5 inches off at 25 yards. Nothing to do, so I picked up a Cabela's catalogue sent to me. Never even thought about a bore-sighter to check if I should do some re-sighting and was surprised that they are quite affordable. With the price of bullets and worst of all, missing something nice, it makes sense to have something to double check things, even at home.

So then here it goes. I'm looking to purchase for this coming season, a bore-sighter that would allow me to quickly see if anything has gone south. I would perhaps not be looking at something that would be too complicated or with many small things that may end up getting lost in the bush (If possible, don't want to limit myself) My rifle is a 7MM Rem Mag and most likely I will have a second one, carbon copy, for my son, so no need for versatility or caliber range. If you have used them and can offer a comparison between types, that's what I'm after.

Thanks for the input.

[deanmc]

Hmmmmmmmm. I suppose it is better than doing nothing but there is no substitute for shooting, shooting, and more shooting.

[twofifty]

If your rifle is a scoped bolt action, you can easily get it sighted in at 25 yards without a bore sighter.

Start by checking that your action bolts are properly tightened, and that your scope is level and tight in its rings. Apply low strength loctite to your scope ring & mount screws.

Then get your scope turrets centered, meaning that if say each turret has a 40 click range from 'top to bottom' and 'left to right', set both reticles to the half way point, i.e. 20 clicks from one side. This gives you access to your scope's full range adjustment potential.

Then set up a target with a bright 10 ring at 25 yards.

Steady your rifle in a good rest, pull the bolt, and look through the bore. Move the rifle until you can see the centre of the 10 ring through the barrel bore. Then, without moving the rifle, click your reticle up/down and left/right until it quarters the 10 ring. You want the scope to quarter the 10 ring while still seeing the 10 ring centered in the bore.

Now take a careful shot at 25 yards. The impact should be very close to the 10 ring. If it is to one side, or too low/high, adjust the reticle to bring the shot to the 10 ring. Fire another careful shot to confirm you are closer to the target centre. Close, meaning an inch or two, is close enough as this setting will get you on paper at 100.

To get your 100 yard zero, look up the trajectory of your round on a ballistics chart, with the software set for a 25 yard zero. Then simply adjust the reticle according to the +/- elevation difference of that round at 100 yards with a 25 yard zero

Now take a careful shot at 100 yards.

You will certainly be on paper, high or low, left or right, but on paper. Adjust the reticle to move the point of impact toward the centre. Now fire a careful 3 shot group. The centre of that group is theoretically where your rifle is now shooting at that reticle setting. Adjust the reticle again to bring the centre of that group toward the 10 ring.

Let the rifle cool. Fire as many careful 3 shot groups and adjust the reticle as often as it takes to get the rifle to place 3 rounds close enough to the centre that you're happy with the results.

10 to 16 rounds should be more than enough to get her done if your bench technique is good and the wind is not blowing hard.

[JM59]

Twofifty described the process perfectly. Bore sighters are really a waste of money especially with bolt actions and I definitely would not rely on one to see if the gun is off or not, just shoot the gun.

For some lever action like Marlins, its very easy to remove the bolt but not so easy with levers like the BLR. For levers and semi-auto's, I simply take a laser pointer pen(the kind used to make presentations), tape it to the end of the barrel and line up the laser with the target at 25 yrds. Adjust the scope to the laser point, remove the laser and fire the gun. This procedure actually gets me closer with the first shot to zero than the process used with a bolt gun.

[Dick284]

Originally Posted by deanmc

Hmmmmmmmm. I suppose it is better than doing nothing but there is no substitute for shooting, shooting, and more shooting.

X2 no short cuts replace being there and putting it down range,

As it should be.

FWIW: my wife's old 270Win never would bore sight, always showed low and right, but that was after plugging MOA or smaller groups at 100yds. (2.5" high)

Never knew why but that's how it was.

[KOOZ]

Bore Sighting is only designed to get you to hit paper at 100 yards.
It sounds like you are trying to find a quick substitute to checking your rifle prior to hunting with it.
By using the method discribed above, you can save your self a few bucks. But this is usally only needed if you remove and replace your scope.
I've had guns sighted in then put away in the safe thinking that they were ready to go but when I went to the range to verify before the hunting trip, I found out that the rifle was shooting a few inches out. I think it has to do with temperature and humidty levels when the scope is initially mounted. After the slight adjustment in colder dryer weather, and a check of torque on the scope ring screws, the rifle usually holds for good, but I still check it before I use it. Especially if it hasn't been shot for a while. I believe in using a good quality scope, rings, and bases. And I mount everything myself. That way I know it has been done correctly. If asked, I'm sure a few guys on this board can share a few stories of horror relying on the local gun shop to secure thier glass correctly only to find out that is was not done right. A loose base screw, missing pieces, ect. ect. Not to say that I know more, but this way I have no one to blame. And besides I take pride in doing it my self.
As already stated, shoot your gun lots and lots, 'cus its fun. You owe that respect to the game you are chasing!!!!

[Jason Balesdent]

Personally I use a Bushnell laser boresighter, great tool to get you close when you instll a scope. However it has been said before and here it is again, the ONLY way to be 100% certain is to shoot the rifle. Aboresighter will only get you close.

[M77RMKII]

When I posted the original question, I decided not to go into details as to why my rifle was so far out of whack.

I have this rifle for some 12 to 14 years. I sighted it in at the range when I changed scopes after the first season (the first scope had a problem) then used it for the rest of the time without there ever being any problem or deviation. Even when I thought I had really jarred the rifle, upon checking, it always stayed true.

This last season, I went from one quad to two, so my Son and myself could get around. This meant that we went to the Kolpin side mounted cases, as opposed to the horn style gun holder on the front rack or over the shoulder. This was my first experience with the Kolpin case, never heard any input or caution from anyone.

We went through some rough terrain, I didn't like the way the rifle was rattling on the case, then when a shot presented itself, it was waaaaayyyy off, the 6.5 inches at 25 yards. A T-rex at 100 yards would have been a clean miss :-).

Now the funny thing or interesting thing about this is that my rifle went south while the rifle that my Son is using, nothing changed. We rode front to back on the same lines.

Our rifles are both Rugers. My Son's an older wood stocked 30-06, mine the synthetic stocked 7MM. Scopes are both Bushnell, his a 2.5X10 mine a 4X12. I believe mine is the "Trophy" line, cost $250 way back then.

So then why would my scope go so far out of whack and not his? Just luck? any tips, tricks to prevent this re-occurring.

This is why I started thinking of a bore-sighter. I know that there is no substitute to shooting the rifle. I would also imagine that any cheap bore-sighter would be able to detect that something moved? I'm not looking to replace target shooting, looking for something that would be able to tell me when otherwise not possible, that something is off.

[Jason Balesdent]

Possible something may have broken in your scope from the rattling? Might be worth taking it to the range, fire a group, hit your rifle HARD with your hand a few times and fire again. Might show if something is loose inside your scope. After 12+ years it may simply have had enough.

[M77RMKII]

Could try roughing it up when quadding in the spring. I should have mentioned that the 6.5 inches were straight off to the side, just like the shaking on the quad. No movement up or down.

[KOOZ]

It could be that the recoil from your 7mm might have finally taken its toll on the Trophy. Or the base screws might be loose.

[elkhunter11]

Kolpin gun boots have been responsible for many scopes being knocked off zero,and for a few damaged scopes.They have a serious design flaw,in that the scope bottoms in the case before the barrel,so the scope supports the entire weight of the gun,and takes all of the abuse over rough terrain.

[igorot]

Not an expert, I used the Leupold boresighter on my new Rem 700 BDL 7mm Rem mag with no problem. The gun was first boresighted where I bought it but it was way off the paper.As everybody else who have use it, the instruction is not that clear but once you figure it out everything would be OK.


Peace

[9mikemike]

Get the bushnell laser sighter, it takes about a minute to sight a gun in roughly. I think thatt I paid $40 for mine.

Way less time than trying to remove the bolt and look through the bbl and TRY not to move it while you put the bolt back in and load a round...

THE BEST BORE SIGHTER EVER MADE: look down the barrel at your intended target at 50 yards and match your scope to it. Fool proof, cheap and no warranty needed. I have a bore sighter, it's got dust on it, wannay buy it cheap?

[elkhunter11]

My boresighter is a bushnell unit purchased many years ago.It consistently gets me on the target within a few inches of bull at 100 yards.Over the years,it has paid for itself many times over in the amount of ammunition saved.