just put a bubble level on my scope to make sure im not canting for the long shots.(350 to 500yds with my 22-250) thats as long as i can shoot acuratly. how i got level: used small level on the action and locked it in place in a rest. next hung a plumb line in a door way and lined up the vertical crosshair of the scope with it... once that scope and gun were level simply put scope level on scope tightened everything up.. rechecked and everything was level.. my problem... when i look thru the scope the cross hairs dont seem level.. when the bubble level says its level it looks like the scope is canting pretty bad. is it possible that it just looks that way to me?? how can i make sure evetyhitng is really level?
First place I can see a problem coming into play is the leveling of the rifle action.
If the action isn't truly level you've made everything plumb to a canted action.
What kind of rifle are we talking about?
Could also be that you naturally cant the rifle and now with everything level it looks and feels awkward.
One way to check (I think this will work) could be by firing some rounds at a large target at 100 yards. First shoot a group at your 100 yard zero setting. Then adjust the elevation up about 20 MOA and shoot again (same Point Of Aim), then run the elevation down to about 20 MOA below (if possible) your 100 yard zero and shoot again. The center of these groups should be plumb, check BEFORE taking the BIG target off the backer. If they're not plumb with each other there's something canted.
The way I like to use the level is this. I put the scope in a padded vise, with the cross-hairs trued-up on some vertical or horizontal reference, and attach the bubble level to the scope, showing level. Then put the scope on the rifle, get into a position that feels good with yours eyes closed, and have some body else turn the scope until the bubble reads level. Then tighten the rings up.
I like a little inboard cant in my prone and sitting positions, and this method lets me get the cant consistent.
I use a bipod and a bubble for the initial adjustment of the rifle, making the rifle sit level on a level workspace.
Then I use a Leupold collimator (and a plumb to level the colli) in the muzzle to adjust the scope level as well. (You can use the collimator to roughly check level later on.)
That pretty much makes it level -but you do need to check things the way Dave described.
I just got back from the range and my .22 LR fun gun was behaving strange. When I dialed for the wind at 150 meters it moved the POI up and down as well, I took the bubble to make sure I´m level - and I was. 100 meters was no problem at all but 200 (about 32 moa) was nearly impossible, the "Dave-Test" verified the problem when I got to our 50 yard range and dialed up and down, left and right...
The rifle had been zeroed while canted. Not exactly the best thing to do , it was windy yesterday and I got a new batch of Super-X...re-zeroed... well, no level. [img]images/icons/rolleyes.gif[/img]
These 22s are quite educational things really, just put targets all over the place and hit them in windy conditions while really thinking what you are doing. Use your tables and an anemometer, good practise to keep your wind reading skills in shape.
I place a 3' target board down range at 200yds. I use a 3' level to draw a plumb line right down the center. A thin magic marker works well.
While on the bench I carefully level the rifle using a small level on the flat of the scope base. While the rifle is level, I peer through the scope to see if the verticle crosshair is perfectly parallel to the plumb line down range.
When this is accomplished I add my scope level and make sure that the bubble is centered when the crosshair is still parallel to the plumb line.
The shooting method DOES sound like a good way to confirm that everything has worked as planned.
Just reading all the responses it is pretty obvious that the biggest problem in the whole leveling conundrum is the initial leveling of the rifle. Leveling the scope is a snap once you get the rifle level and get it to stay there. If you are counting on the flat top of your rifle (if it has a flat top) to be level, you are beginning with a mistake. It probably isn't. Same for putting either scope or rifle in a vise. Close, but no cigar, as they say. Our goal here is to be sure that our rifles are shooting level. That does not necessarily mean the rifle and scope have to be level in relation to each other, although ideally they should be. I really like Dave's idea of shooting a group, drawing a reference line, then shooting above and below the line and see how the upper and lowers line up with the initial center. Shooting groups (as Dave said) would allow you to throw out "flyers" in your calculations. This method, assuming you can shoot the groups (no offense to anyone meant with that statement, it includes me) is foolproof. You would have to choose the right day...no wind, etc., but in the end you would know exactly how your rifle is shooting and you could make the appropriate adjustments. Ignore what any of your levels say about your gun and your scope, just pay attention to HOW YOUR RIFLE SHOOTS! THAT IS THE WHOLE POINT ANYWAY. Thanks for the idea, Dave. I will put it to the test as soon as I get my new knee and can get back on the range.