Group issues

[Rem81]

Today I was fireforming brass for a new 25-06ai. Been using nosler box ammo all have fired fine and look good. First 20 shots 2 weeks ago shot great to properly break in barrel and was cleaning with a couple patches. Went out to shoot this evening first one in bullseye and next 2 were straight down 2 inches and 1/2 inch group at 200 yards. Let barrel cool down and shoot anther 2 groups and same results. Do you think it is from fireforming to ai, just does not like ammo, need cleaned, something lose, have not shot any fireformed ammo!

 

[WildBillG]

It could be just different environmental changes causing it. A little more wind can cause bullets to drop but there are are things too. Might even be it takes a few more shots to get your barrel properly fouled.

 

[Tiny Tim]

Try leaving the barrel fouled and see if it does the same thing with your cold bore shot. If you only have twentyish rounds through it, give it another 50-75 and see if your barrel "settles down". Also see if it does the same thing with loaded and fireformed cases. If it doesn't do it with the fire formed cases, its likely a load/powder issue. Seems strange for that though.

 

[KY_Windage]

I've been known to bump my beam powder scale, not realize I had moved one of the weights and load some with too little powder.

Also, scope might have shifted due to a loose ring screw.

If it liked those bullets before it is unlikely it suddenly started to dislike them.

 

[Hatrick]

If you had it apart to clean it (remove from stock) make sure the barrel has no pressure point and the screws are tightened to specs.

 

[RT2506]

Are you shooting the same lot number of ammo on your second outing as you were in the first outing? Changing lot numbers means they were not loaded with the same batch of components and that will cause differences.

 

[Rem81]

I've been known to bump my beam powder scale, not realize I had moved one of the weights and load some with too little powder.

Also, scope might have shifted due to a loose ring screw.

If it liked those bullets before it is unlikely it suddenly started to dislike them.

They were nosler box ammo shot 2 and 3 group but first cold shot is always 2 inches higher. Have not shot any reloads yet

 

[Rem81]

If you had it apart to clean it (remove from stock) make sure the barrel has no pressure point and the screws are tightened to specs.

I am 99.9 percent it is not a scope issue, took action out of stock and had the action screws marked with a fine sharpy after torqued, mag box is loose also barrel is free floated 2 one dollar bills together probably more

 

[Rem81]

Are you shooting the same lot number of ammo on your second outing as you were in the first outing? Changing lot numbers means they were not loaded with the same batch of components and that will cause differences.

They could of been accidental move for one box from another, also they are from the older red box nosler ammo which they have been in the black boxes for years now!

 

[tnek13]

Is this a new rifle or a new chamber or a new barrel? If it is a new barrel talk to the maker.

 

[Rem81]

Is this a new rifle or a new chamber or a new barrel? If it is a new barrel talk to the maker.

Rifle is completely new.

 

[mwkelso]

Might be worth repeating the test again. Perhaps just a rough day at the range?
I know I have had those before...
I don't know how far you're wanting to chase the issue, but there are the little things like inconsistent ignition from a sticky / light firing pin or a rough trigger that may be worth looking in to as well.