View Full Version : Did I sight it in correctly ?

December 28, 1999, 11:32 PM
I got a Tasco World Class 3-9 x40 for christmas. Put it on my Mini-14 and took it to a friend who is a gunsmith and asked him to boresight it. Well...he must have done a very quick (sloppy) job, cause when I went out to shoot it, I wasnt even hitting the target (at all) at 50 yards. So, I moved in real close (20 yards) just so I could see where it was shooting...5-6 inches high and 5-6 inches to the left. Started turning the windage and elevation screws and started getting closer to the bulls eye. Then moved back a ways and did it all over again. Well after about 75 rounds and 5 different targets, I got it dead on at about 70 yards. (the maximum distance I could get from the target) I will go to a real range at some point in the near future to fine tune it a little more, but I was getting 2 inch groups at 70 yards. Not bad for a Mini-14.
Did I use the correct procedure to sight in the scope ? I have never done it before, so I just followed the directions that came with the scope. By the way, I think the Tasco is an OK scope for the Mini-14, since it is an inexpensive gun, I just couldnt see putting a Leopold on it. Opinions....

George Hill
December 29, 1999, 04:24 AM
Sounds like you did pretty good.

The way I sight a rifle in is a little different.
I use sandbags and bench the rifle very tightly in there so there is minimum movement.
At a target of know range I fire a single round. If I mounted the scope correctly I should be on the paper. Then I adjust the recticle so that the cross hairs cover the hole. Thats what I call a Fast Zero. It is not a really good method - but its fast and pretty close if you bench and bag the rifle right. After getting my Fast Zero I will then tune it. Firing groups of 3 and adjusting it accordingly.
The Fast Zero - or as its called in the "Ultimate Sniper" Manual - a 1 Shot Zero... will not be a true zero. I dont know any snipers who would ever do a 1 shot zero. I call it Fast - because after that shot - adjustments are quick and easy.

"A fear of weapons is a sign of retarded sexual and emotional maturity." - Sigmund Freud

December 30, 1999, 11:05 PM

George Hill did a good job explaining his method and covered some good points. Here is another similar procedure I use.

The steadier the rest is, the better and faster results you will get. A steady shooting bench with a rifle front rest and rear rest, work the best, but if not available there are alternatives, like the prone position using sand bags for the front and a good shooting shoulder position for the rear. You are looking for consistant stability each time you fire and attempting to elimenante the humun factor as much as possible.

For most guns that have a scope mounted about 3/4" high (most common) set your target at 25 yards. Follow George's suggestion and fire one good shot (big paper will help here also, as you first expereinced it is difficult to make an adjustment if you can't print on the paper). Make adjustments on one plane at a time, windage then elevation or elevation then windage.

For example, you shoot at 25 yards holding dead center and bullet impact is 3" high and 5" right. If the shoot was good (meaning the shooter did not jerk the trigger or push it off), I would then adjust the windage in the direction of LEFT 80 clicks (assuming the scope afjustments were in 1/4" MOA. Then I would shoot another round. If the second round is within 1" of 12 O'Clock, I would then adjust the elevation in the down direction 48 clicks. You need to adjust and shoot until you are within 1" of center in any direction, ideally dead center.

In most centerfire calibers this should put you about 2" high at 100 yards and about dead zero again at 200 yards. As you know, 25 yards is not a good test for a 100 or 200 yard zero and beyond. You now need to take the target out to 100 yards and make fine adjustment to get your zero reliable.

When you start fine adjustments at 100, you are better off shooting a three shoot group before making any adjustments. If you are not getting a good group at that range it is going to be difficult to establish a reliable and fine tuned zero. Your gun should hold 3" groups at 100 yards and many do 1.5 - 2" groups. A few do MOA, but those are normally the one's that have had some accuracy work perfromed.

One other little hint I would like to pass on. Most scope adjustment mechanisms are one-sided screw adjustments with a spring load from the opposite side. Sometimes you can make an adjustment and the crosshair will not actually move or not move the entire adjustment. I rap my knuckle againt the housing to jar the crosshair mount to seat into the new adjustment before I shoot the next round.

OK, and one more thing, the less expensive scopes do not always follow the adjustment scale as perfectly as do the higher quality models, so 4 clicks on a 1/4" MOA adjustment might not give you exactly 1" at 100 yards.

I'm sure you are aware of all this, but I hope it helps....

Best Regards.....
"Train to Defend, Train to Survive, Train to Win"