Need help diagnosing group problems

[Prairie605]

This is from a buddies new Remington 700 sps. 20" barrel 10 twist. We can't seem to figure out what is causing the poi change from shot to shot. We replaced the factory houge stock with a stockeys brand bench rest stock. We have tried shooting off a bipod versus bags with no change. The original stock wasn't very stiff so I thought a better, stiffer stock might make the difference, but it didn't help. We did get .5" groups the first day he shot it, but we haven't been able to get a good group again since. The target shows the bullet drop. The lines indicate the first shot then the poi drop for the second. Some groups were factory hornady match. The others were hand loaded Bergers. I shot some and he shot the others. So I don't think the shooter is the problem.
He did adjust the trigger down from the factory setting after the first shooting session. Could this cause the erratic grouping? I have a timmney I'm going to put on and shoot this evening. That's all I can think to do at this point. The barrel is floated and the scope is a new vortex. Rings are tight and so are the action screws.

 

[Barrelnut]

Those are some pretty big POI changes. Since the rifle was fine the first day out, I would suspect the scope. Even good scopes go bad sometimes. Maybe try a different scope or try the suspect scope on a different rifle.

 

[Prairie605]

Yep, forgot to mention i got a leupold ready to put on at the range if the new timney doesnt help. The vortex he has was bought new with the rifle, so i was hesitant to think it was already bad, but i guess stranger things have happened.

 

[shaughn]

I would remove the scope and check to make sure all screws in the base are tight or none are broken off.

The other would be the placement of the rings in the base, make sure they get a good consistent grip when tightened.

The scope is a good possibility, duds do make it out from time to time.

 

[BountyHunter]

1. Check the base screws.

2. check the action screw tension for correct torque and for binding in the barrel channel

3. change scopes.

4. Does it do the same with different shooter?

 

[HammerB1]

+1 on scope being the culprit. I've had several go bad, even a nightforce. But to start, check all base and ring screws.
Brian

 

[Prairie605]

Looks like everyone was spot on about the scope. We took off the vortex and put on a Leupold and it started hammering out .75 groups.

Thanks for all the help and suggestions guys.

 

[jaybo]

I have had two brand new scopes that were bad when I bought them. One was a Zeiss and the other a Swarovski. It makes a very frustrating time at the range and makes you question your capabilities.

 

[Prairie605]

I know this is an old post, but felt the need to update.
The original scope I posted about( Vortex viper 4x18 ) I believe, went bad the second time we went to the range. It was replaced on the spot at scheels the day we discovered it was defective. My buddy upgraded to the 6x24 viper vortex for a little extra money.
We mounted the new scope and zeroed a few days later. The very next time out the second scope went south. I've spend 3 months trying to find a load for this rifle and all the time it was a bad second scope.
This was 2 bad scopes in a row. Both were 700-900 dollars. I would expect much more quality for this price.

At one time I was considering buying one of these scopes, especially with their 40% veteran discount. But at this point my opinion of vortex is they are pure junk. I know many thousands of people swear by them, but I for one will never buy one. I can't fathom putting one of these on my rifle with a $650 elk tag in my pocket and being in Colorado or wherever and it break. I've owned many Leupold's over the years and never have I had a bit of trouble with them.

Vortex may have excellent customer service, but I truly believe that's because they get a lot of practice.

 

[jaybo]

I understand how you feel. It is very frustrating to buy something brand new only to find out it is bad out of the box, especially when you pay top dollar for a product attempting to buy quality. I don't own any Vortex scopes but have read good things about them. With most brands, sooner or later someone is going to get a lemon. You were just unfortunate to get more than your share. I have Night Force, Swarovski, Zeiss, Leupold, Nikon, and Burris. Out of all of them, one Swarovski and one Zeiss bad out of the box plus a couple of Leupold that went bad.