I just put a scope on my 6.5x55 (it is built on an Argentine Mauser M98 action) and I could not get it to shoot with any consistency. As I was packing up and getting ready to leave, I noticed that there was a slight "give" to the scope, meaning that it was slightly loose in the mount somewhere. I didn't have any tools to tighten everything up with me and I was out of ammo anyway. I was wondering if the mount being slightly loose was probably what caused the irratic shooting?
I am also a new member. Looks like a nice site.
joe

For sure the loose screws is the first place to look. Check your bases mounted to the rifel as well. Then chck your scope. There are certain inch pounds you should tighten too, so dont just go cranking away, you can shear off screws and crush scope tubes.

When you remount, EVERYTHING, use blue locktite on all the screws and get a Wheeler torquing screwdiver.

I found the problem. The objective bell end of the scope (I don't know what it is called, but the end opposite of the end you look through)was actually loose and had some play in it where it attched to the housing where the recticle adjustments are located. So the scope itself is defective. It is an older scope so I am not surprised. Thanks to all who responded and I will carefully and tightly install the new one. Really, I am surprised it shot at all as I did get one MOA 3 shot group. But the rest were awful.
joe

Glad the fix was an easy one. Hard to spend too much on a scope, easy to spend too much on a rifle.

Joe--Welcome to the site. A good lesson to be learned from your experience. You didn't say what type scope, but I'm guessing a lower priced one that saves one money. You are now out the cost of some ammo and a trip to the range and you got nothing accomplished. The scope will probably need to be sent off for repairs--more cost. Get a Leupold (and yes they do give problems too on occasion), and for the most part they are reliable.

Thanks carpetman1. The scope was a Tasco World Class. I believe it can be repaired. The web site says it will cost about $48. That's a lot cheaper than a new scope, but I think I will get a new one anyway and send this one off for repair and keep it as a spare. The repair time is several months, they say. The ammo is not a big deal as I reload anyway.
joe

Joe--You often hear Tasco's called Trashco's, but my late gunsmith had a Sweeny Collimator for setting up scopes. He said Tasco World Class were amongst the few other than Leupolds that held their zero through the variable range. Was a time when Tasco World Class and Leupolds were about same price. I do have one on my 22-250 and it has not given me problems. Understand about the ammo not being a big deal when you reload and were going to shoot anyways. But add in those $48 repair bills, postage and trip to post office etc and sometimes a cheaper scope really aint.

The older World Classes (from the eighties) weren't bad for the money. Still I'd get a new one and keep it for a spare.

Back in the late seventies I purchased a Tasco World Class scope. Cost was about 1/3 the price of a Leupold. Mine was a3-9x40 and I paid around $60.00 for it, IIRC a new Leupold3-9x40 was $150-$160. It was a satisfactory scope, I wound up giving it to my brother-in-law. I think it would be stretching things quite a bit to put it in the same class as a Leupold, and for sure it wasn't in the same price range. Later on, early 90's IIRC, I purchased another World Class scope. It was a piece of @#$%. Tasco had been bankrupt and sold or re-organized and the new World Class scopes weren't near as good as the original. I got rid of that one ASAP.

That was almost exactly my experience. The newer ones are crap.