doublegunshop.com - home Forums General Discussion DIY Gunsmithing @ doublegunshop.com Scope Dope

What is the 'redialing the knobs to re-dead zero a mounted scope. I have an older Weaver USA mfg. 1" tube 2X7 vari-power that is locked at about 7 sclicks low and 4 clicks rt. and there is no more adjustment left- I am used a Lazer colimnator-bore sighter. This is on my 1950M70 in .220 Swift cal. ammo for that rifle is scarce and pricey, so prefer to to the rough adjustments with a bore scope- final targeting will be a 200yds. on our range "on paper" later on. RWTF

If you are trying to center the cross hairs,,run each adjustment all the way to it's limit (doesn't matter one way or the other).
I think you have done this all ready.

Now reverse EACH adj and go all the way to the end of it's limit the other way,,,AND count the 'clicks' when doing this.

Then go back the other way once again with each adj...BUT only go HALF the number of clicks it took above.


That should get the Xhairs just about centered.

You probably know this but once you center the scope as Kutter has described. Use the rear windage screws on the rear mount to get the scope windage as close as possible. Then use the scope windage adjustment to fine tune. You should have plenty of adjustment after that.

I don't own a "bore scope" or a laser for sighting in rifles. I set the rifle up on sand bags, remove the bolt and adjust the rifle until the bullseye is centered in the bore. Without allowing the rifle to move itself I then move the crosshairs until it is on the bull. Then, test fire one round. If you're certainly it was a good trigger pull and the crosshair was "on" when the trigger broke, keep the rifle immobile while you adjust the crosshairs to be dead on the bullet hole. Another round or two will verify the zero. Very little ammo used. I've done this for other people and they were amazed, but it's really very simple. You're just adjusting the scope to where your rifle is shooting that load.

I do similar, but don’t worry about keeping the rifle steady. It’s easier for me to bore sight at fifty yards, then just move whatever the scope clicks claim to be to put that shot a bit high at a hundred, based on the drop charts. I think one still has to burn up some ammo to adjust and verify. Careful with old scopes, some need a shot or two to settle into the adjustment, so I wouldn’t necessarily adjust on every shot.

I've used the exact same method as Stan for years, and it saves a lot of ammo and aggravation. It's more fun to use ammo shooting small clusters than walking holes around a target. I'd prefer to never use a collimator spud in the bore of any rifle that I was able to remove the bolt and see through the bore. I feel this way for the same reasons I'd avoid running a cleaning rod in the muzzle when cleaning from the breech end is possible. I just don't want to risk any unnecessary wear or damage to the crown and muzzle rifling. For my muzzleloaders, I have made nylon bore guides on the lathe to use when cleaning or shooting at the range. If I'm careful, I can typically bore sight to within a couple inches of the aiming point at 100 yards. Without even firing a shot, that's as close as a lot of guys seem to manage after burning up a whole box of ammunition. Two shots using the method Stan detailed will usually get the rifle dialed in, and the third shot erases any doubts.


Agreed, except I have found that simply tapping on the reticle adjustment knobs with the end of a fired brass case after each adjustment seems to take care of any reticle movement lag, without firing extra shots. A couple light raps will do, and the brass is non-marring.

I am presently working on the zero on a 22-250. I have it at the top of the X in the bullseye at 50 yards with three rounds that can be covered by a dime that cut off the left top of the X. Now out to 100. Should I just adjust the scope reticle up before firing a shot group? If so, where do I want the crosshairs to be at 100 yards? I anticipate shots at coyotes at 200 or better. I have never been much of a rifle and scope guy as many can tell by my question.

I would shoot at 100 at see where it's at

Perry, I'd just shoot it at 200 and see what adjustments are needed. I use a similar round for crows, a .220 Swift with 52 gr. hollow points. I want mine sighted in at 200, no more than that, as the bullet rise (in comparison to the line of sight) has caused me to miss crows at closer distances when I forgot to hold low. With coyotes that shouldn't be near as much of an issue, as the vital area is so much bigger than that of a crow. With my .22 Magnum I sight in at about 100 yds.

Because I don't shoot them enough to remember the drops I like to keep a tiny cheat sheet taped to the top of the ocular bell of my scope, with holdovers (and unders) from 50 out to about 350 yards. Handy and quick to check.

Interesting generality: Most "hunting cartridges" (high powers in general), if they are dead on at 50 yards, will be 1-1/2"-2" high at 100 yards and then be back at 0 somewhere past 200 yards (230-240-ish). There are cartridges which will not fit that description, of course. The .45-70 and other BP cartridges are "too slow" and your Swift (I haven't looked) may be "too fast" for that particular curve. We have an indoor range with a 50 yard backstop. I'll sight rifles in to be dead on at that range and then move to greater distances when we get to opportunity. Of course, I'll make any tweaks at the longer range if needed.

Edit: I meant to add there are a number of ballistic calculators available on the 'net but they often need data that isn't readily available or must be assumed.

Thanks keith, yes I’ve tried different tricks, I’ve even had some luck with running a couple of clicks past, then coming back, but Ive heard it so many times that, such and such a rifle is a bear to sight in, but once it is, it’s a tack driver.

Yah, if the ammo’s pricey, I like to fiddle for a few minutes, looking through the bore and adjusting the glass, then commit to the first shot. I don’t steady the rifle much, just move the cross hairs till they look centered and a bit high at fifty. I don’t like shooting at my point of aim.

If I don’t need to, I also prefer not to turn and old scope to its stop. Even with a light touch, I’ve had a couple somehow get off track, and be far from worth thinking about having them fixed, so they just sit with the rifle, broken. Anyway, minute of deer vs 220 swift, I think in the end it’s probably better to shoot the swift for group, and stretch it out a bit.

I read today that there are bullets available now that will let the ol' Swift be loaded effectively to 4500 fps. That's smokin', and puts it in rare air, as far as centerfire varmint calibers go. Of course, the depleted uranium rounds that are used out of the M1 Abrams smoothbore gun leave at somewhere between 5700 and 6300 fps, according to who's talking, but that's another class of varmint gun, eh?

Eighty-eight years old and still outrunning the bunch. Pretty cool, IMO.

I read this trick somewhere on how to recenter a reticle.

Go to a bathroom mirror and put the objective bell up flat against the mirror. When you look through the scope you should see 2 reticles, adjust the knobs until both reticles are aligned.

Don't know why but it seems to work fine.

Cantankerous fellow that I am, I may just try that with a living room mirror.

Years ago when I owned a 22-250 and I wanted to zero it in, looking at various books I read that all bullets cross the path of your eye twice. I forget now what the 22-250 was with a55 grain bullet but I believe it was 27 yards and 104 yards.
So as Stan stated if the gun is a bolt action remove the bolt and set a target at 27 yards and with the rifle rested look through the bore to set the rifle to hit the target then look through the scope.
Again if I am not mistaken a chuck at 400 yards aiming at his head the bullet would drop 4" at 3810 fps.

I own 2 Bushnell collimators. One puts the gun close to zero and the other 4" high. They still save a bunch of money on ammo.

That exact distance has to do with the measurement that the exit pupil of the scope is above the centerline of the bore, among other things. I always liked to keep my scopes as low as possible. "See-thru" rings, and other very high rings, exaggerate the numbers and caused me more problems than they were worth. JMO, OMV.