Hey everyone, sorry for all the questions so early on, but I just got a scope put on my .375 this weekend, and when the guy was boresighting the rifle, he told me I better shoot it at 25 yards before I go out to 100, because anything over .32 caliber was a crapshoot when it came to boresighting? After I went to the range, I hope he's right, because it's either that or he just did a piss poor job of boresighting it. Just wanted to see if that was true or if there's some special trick to it, thanks again!

I don't believe it. I just bore sighted my 416 Rigby at 50 yards using a 50 yard pistol target. Fired one round adjusted the scope and was in the 10 ring. Moved it back to 100 and did the same thing. Remember the purpose of bore sighting is just to get it on paper. At least that is what I use it for. You need a big enough target so that you can accurately center it in the bore of the rifle.
Peter.

I suspect he used a "bore sighter" tool and he probably doesn't have the right collet.

If you are having trouble getting on the paper, the easiest thing to do (assuming its a bolt action rifle) is to remove the bolt from the rifle and then set the rifle on the bags and make sure it'upright and not canted and won't move easily. Use the scope to get centered on the 50yd target. (or 25yds target, I like 50yds) Look down the bore and move the rifle gently until the bull is centered in the bore. Without moving the rifle at all once the bore is centered, adjust the scope so the reticle is centered on the bull. Shoot the rifle and you will be on the target. Proceed to sight the rifle from there, move out to 100yds when the rifle is shooting dead on or an inch or two high at 50yds.(dead on if your using the 25yds target)

Another set of hands is useful to keep the rifle from moving after you've centered the target in the bull and while you're adjusting the scope, but this can be done solo. If the sope is so far off that when it is centered at 50yds you can't find the target through the bore at 50yd, do the whole thing at 100yds to get the two closer, then do it at 50yds again before shooting and proceed as above.

There is never a really any reason to bother with "bore sighting" with a so-called "bore sighter" with a bolt action rifle unless you have the equipment or had a gunsmith mount the scope in his shop. Even then, using your bore to double check to bore sighting will often save time and ammo.

Actually bore sighting the rifle as I descibe is what Peter did regarding his rifle int he post above, I think.

JPK

quote:

...because anything over .32 caliber was a crapshoot when it came to boresighting

Bullshit. The guy doesn't know what he's talking about.

The chances that the scope will be off paper has nothing to do with the bore diameter. It has more to do with the straightness of the barrel, scope, and mounts than anything else.

As JPK said, the guy might have only had a .30 caliber spud. Follow his instructions on sighting through the barrel, and you should be okay, unless the scope, rings, or barrel are off.

George

Just follow the procedure JPK outlined. Works perfectly.-Rob

There are really two different procedures involved here - bore sighting and sighting in.

Bore sighting is simply lining up the sight with the bore. This can be done at any convenient distance. Anywhere from the minimum focus distance of your scope, to infinity. Once this is done you can be fairly confident that your first shot will be relatively close to your point of aim and, if your target is big enough,the paper will catch it.

Sighting in involves having to know your bullets trajectory and your desired "point blank" distance. For most high intensity cartridges, a scoped rifle can be sighted in at 25 yards and you'll find that your shot will cross the point of aim the second time at around 200 to 225 yards. For iron sights, sight in at 12 yards.

You then shoot at the longer distances to refine the sight setting.

When sighted in using this method you'll find that your first shot on paper will be surprisingly close. In an emergency or if you are not able to shoot at the longer distance, it will probably get you close enough to save an otherwise ruined hunt.

This sighting in procedure was touted by the likes of Jack O'Connor and Col Whelen back in the 20th Century. It worked then and works today.

JMHO

Ray

Thanks, guys, I was lucky because the piece of paper I had was 36"x36". At 25 yards it was probably not much more than 3-4" from the left side of the paper and probably 6 inches low. It took a few bullets to get it close enough there before I moved out to 100 yards. The couple of rifles I had bore sighted before were much closer than that, and I was hoping for the same with the .375.

Kind of off topic but this reminds me of an experience from days gone by. This guy shows up at the ranch to go deer hunting with us with his new outfit and rifle. We take him out and there is a buck standing at about 150 yards. he proceeds to blast away with all of his shots hitting about 10 feet to the left of the deer. After said deer departs over the next ridge, I told him he should check his zero. He says no, it's right on, my gunsmith bore sighted it for me just last week.

" He says no, it's right on, my gunsmith bore sighted it for me just last week."

Reflecting that there is a vast common misunderstanding of what a simple "bore sight tool", of any type, can do, or what it should be expected to do.

When ever I put a scope on a rifle I bore sight it in. And I come real close to with in where I want to be at with the rifle at 100yds.

A thing I've noticed is to eye through the bore a bit far back (say about one meter) I think you are less likely to be "out of parralax" in terms of your eye to the centre of the bore.