Grouping Problem

[Oklahunter1]

I am having a issue with my shooting and need advice from the guru's. I'm sorry for the long post but wanted to give all the details. I have a 6.5x284 with a Zeiss 6x24x50 scope. I have checked all the screws, scope is mounted solid. I zeroed the rifle at 100 yds. I did not have my bipod on the rifle while zeroing off the bench rest. I put my bipod on the rifle and went to shoot at a target I have set up at 439 yds. After 3 shots not hitting, I went to see where I was hitting since I have a wooden backstop set up. I was hitting 4-6" high and 6-8" to the left. There was only a 2 mph wind. I assumed it was something I was doing causing this. But decided to go check my zero just to be sure. When I checked I was now a inch low but my left and right was dead center! This is without a bipod. So I adjusted up the 1". Put bipod back on and went to shoot again. After 2 shots not hitting target I went to look and was hitting 6-8" high. I went and checked my zero with bipod on, I am 1" high! Anyone have any ideas? Any help would be appreciated!

 

[Jud96]

If you're going to shoot with the bipod in the field, then you need to zero the rifle how it's going to be shot in the field. This is a common issue when zeroing a rifle on a rest then using a bipod afterwards. It doesn't happen every time, but it's common. It can be worse if you're "pre-loading" the bipod and the stock isn't very rigid and is flexing.

 

[Oklahunter1]

If you're going to shoot with the bipod in the field, then you need to zero the rifle how it's going to be shot in the field. This is a common issue when zeroing a rifle on a rest then using a bipod afterwards. It doesn't happen every time, but it's common. It can be worse if you're "pre-loading" the bipod and the stock isn't very rigid and is flexing.

I can see that and will definitely do that. I was just wondering from zeroing the rifle without bipod and then when I rechecked the zero with out the bipod my zero changed. Has happened twice, my zero changed both times I've checked it. Only thing I've done is put bipod on and take it off.

 

[chav0_12]

I can see that and will definitely do that. I was just wondering from zeroing the rifle without bipod and then when I rechecked the zero with out the bipod my zero changed. Has happened twice, my zero changed both times I've checked it. Only thing I've done is put bipod on and take it off.

If you're loading the bipod even slightly, you could be causing pressure points somewhere in the system. You could also be doing something slightly different as far as sight picture if going from bench to prone. There are a lot of variables that could be changing.

 

[VinceMule]

Apparently, Your bi pod = po go sticks

 

[Mikecr]

An inch shift at 100yds with the same rest is not good. I would do more testing of that with disturbance/restoration of gun/rest.
It's like your stock is very sensitive to rests.

 

[Oklahunter1]

Thanks everyone for your suggestions. I put bipod on and rezeroed. When I put bipod on I was 1 1/2" high and 1" to the left. This might explain why I was shooting high and left at my 439 yd target. Weather here is VERY windy. Looks like Monday or Tuesday I can see if everything works. If it does it seems my stock is sensitive to the bipod being on there. We'll see!

 

[Oklahunter1]

Hope all of this is making sense! lol

 

[L.Sherm]

Is your barrel free floated after you put the bipod on and try to shoot it with the bipod, some forearms on stocks are not that ridged. Check the free float on your stock when its set up to shoot.
Is the rifle bedded?

 

[FireFlyFishing]

What make/model is the rifle? Is this a new rifle?

What make/model is the bipod?

What type of ammo are you using?

What is your group size at 100 yards?

I too am curious if your barrel is free floating? If it is, can you grab the fore end of the stock and flex it with your hands where it contacts the barrel? If your hands can do it, the leverage of a bipod certainly can.

You mentioned you checked the mounting screws for your scope. How? Did you apply the manufacture's recommended torque specs?

 

[old_heli_logger]

Apparently, Your bi pod = po go sticks

Hahaha, yep! A bipod on a hard surface is a pogo stick...try your bipod on a softer surface like grass or dirt.
Good luck

 

[VinceMule]

Is your barrel free floated after you put the bipod on and try to shoot it with the bipod, some forearms on stocks are not that ridged. Check the free float on your stock when its set up to shoot.
Is the rifle bedded?

Commonly known as barrel slap. I like a business card thickness free-float at a minimum.

 

[VinceMule]

The purchase of a bipod is no place to be a tightwad...quality pays big dividends.

 

[cajun]

I can see that and will definitely do that. I was just wondering from zeroing the rifle without bipod and then when I rechecked the zero with out the bipod my zero changed. Has happened twice, my zero changed both times I've checked it. Only thing I've done is put bipod on and take it off.

How many shots are you shooting to comfirm zero? One of the take aways from the hornady podcast on statistics and group size was the need for enough data to have confidence in the result. This same concept applies to your zero.