Accuracy Issues... Cant figure it out

[Braunschweiger]

In my opinion... if these are custom rifles... they "should" shoot factory match ammo fairly well. I would start with buying a few boxes of ammo and seeing what happens. The obvious other points are to make sure that your scope base and rings are torqued to spec. I would then make sure your action screws are also tight and torqued to spec.

When at the range I wouldn't worry about trying to adjust your point of aim to match point of impact. Shoot the exact same place every time so that you are taking the optic out of the equation (other than to see your target)

 

[Tank308]

I brought a 300 Win mag and 7wsm, both very good custom guns which have always shot well to the range the other day. Neither would shoot accurately. I went home and cleaned them both very well. Went back to the range and no difference. The only thing I can think of is the heat is causing some sort of problem??? Handloaded ammunition . Any thoughts??? I need to figure this out .

I'd measure free bore. And have throat erosion checked. My magnum shot great and then one day didn't.

 

[CaptnC]

Are you running a 130 grain pill? What's the charge? I'll guess 53.5?

Yes sir, 130gr Nosler Custom Competition...
IIRC it was 54.3gr...I'd have to double check to be sure.

 

[MNbogboy]

I brought a 300 Win mag and 7wsm, both very good custom guns which have always shot well to the range the other day. Neither would shoot accurately. I went home and cleaned them both very well. Went back to the range and no difference. The only thing I can think of is the heat is causing some sort of problem??? Handloaded ammunition . Any thoughts??? I need to figure this out .

Another thought concerning weather could be a change to your rest/bags.
The heat will affect the material on your bags (depends on the type & how they are adjusted). The plastic material on some cheaper bags gets real "sticky" in hot weather, hindering a "free" recoil. Inconsistent recoil could possibly cause a problem, especially when it happens with two rifles at the same time.

 

[ThrdKllr]

Develop a list of what the two rifles had in common on the day the accuracy fell off. Everything. Are they both loaded with the same powder or primers? Environmental issues. Difference between temperature and humidity when loads were developed and when they gave bad accuracy. Different bags/rest. Shooter not on his A game. How long since Both were cleaned. Mirage maybe? I don't see how it can be mechanical with both rifles doing it.