Rifle Scopes Scope? Groups low horiz. dispersion, high vertical

[mram10]

Took my friend's savage 7mm out the other day. He was complaining of bad groups. I shot a couple 3 shot groups at 200 yds and found that it was about 1.5" side to side and 5" vertical dispersion.
Variables:
store bought ammo
Shooting off of hard ground with bipod
light gun
right hand lightly on trigger and grip
left hand in a fist under rear of stock with light cheek weld.
Is it the gun jumping?
Is the scope off?
Thanks guys.

 

[Topstrap]

Re: Scope? Groups low horiz. dispersion, high vertical

Lets see, in the order of your questions and if that could cause some of your results.

Possibly
Possibly
Possibly
Not necessarily
Possibly but not necessarily

Possibly all the above, hard to get good accuracy with the gun jumping around due to some of the above
Not usually a factor in bad groups unless scope is junk

With the questions asked this is about what to expect. With so many variables you can't get solid answers. I think initial testing to see if a gun will shoot still should be done at 100 yards to help eliminate Mother Nature as a factor. At 200 yards 1 1/2" horizontal spread isn't that bad, that equates to 3/4" at 100 yards. The verticle spread could be any of the things you listed except for the scope being off. More time is needed to eliminate so many variables so you can sort thru them and find the problems. Is that gun a 7-08 or a 7mm magnum, shooter skill also has to be taken into consideration? Hard to make a judgement on a few shots and poor prep while making an accuracy test.

Good luck

Topstrap

 

[mram10]

Re: Scope? Groups low horiz. dispersion, high vertical

Just to clarify, I only had two questions. I wanted to list the variables to aid in solving the issue. It is a 7mm mag. I shoot fairly often and do pretty well with my 300rum and 338 edge, so I don't think it is that. Side to side isn't my concern. The vertical is.

 

[billyburl2]

Re: Scope? Groups low horiz. dispersion, high vertical

Factory ammo or hand-loads? Has the rifle grouped in the past? Do you have a proven scope that you can put on the rifle? Have you checked all the connections? You have to start eliminating some of the variables...

 

[Temp9]

Re: Scope? Groups low horiz. dispersion, high vertical

Try shooting a 10 shot group or two. It'll give a whole lot more information than "a couple 3 shot groups". Also, what ammo?

 

[mram10]

Re: Scope? Groups low horiz. dispersion, high vertical

150gr powerpoint, I think. It shot great with bought ammo last year with the same scope. He said it hasnt been dropped and nothing has changed. I guess the big question is, would the scope malfunctioning cause a vertical error only? Or would it cause vertical and horizontal?

 

[mram10]

Re: Scope? Groups low horiz. dispersion, high vertical

UPDATE:
Corrective actions so far:
- Installed a EGW tactical rail (used nail polish in place of locktite)
- Installed new 30mm Warne Rings (not the best, but he doesn't want to spend more)
- Rebedded front lug area (ended bedding job 1 1/2" in front of lug)
- Filled hollow front stock areas with fiberglass to add rigidity.
- Checked action screws for correct tightness
Took it out today and shot crappy again. Handloads and bought ammo.
After all that, found the Burris Tac30 was my problem. Don't know what exactly, but ruled out everything else including trying out a Burris E1 scope. That scope shot great. Now to test Burris customer service