Is this cold/warm bore shift normal

[Vandy321]

What do ya'll make of this?

Rifle was zero'd initially after a few shots, not a cold bore zero. Wanted to fix that...

Targets 1-3 are cold bore, 10 min between shots.

Target 5 I dialed down .4 mil...shot 1 was cold bore to test new zero. Next shots were with shorter wait, warmer barrel. 3 minutes between shots 1-2 and 2-3. Shifting down and right as barrel gets warm.

Target 6 was shot inside of 1 minute from target 5...about 15-20 seconds between shots...hot barrel, group solidly down and right.

Normal? Shooter error? What's the deal?

Barrel is fouled, at least 50 down it since last cleaning.

It is a hunting rifle. I'm happy with the single cold bore shot/zero...but this makes me want to build another rifle and zero it warm for banging steel.

 

[antithesis]

Were the rounds chambered during the wait time? Letting the round cook in a toasty chamber can change things.
Was the barrel clean or just cold?

I don't know jack about what is actually going on so just questions that I would consider. If it was me I would have shot 5, 5 shot groups and then gone back another day to test a cold/fowled bore. I also don't really believe in cold bore. I regularly get shifs with a clean bore but not always with a cold bore - says it is more me than the rifle.

 

[Vandy321]

Dirty barrel, rifle shoots better fouled. Targets 1-3 were cold borex then brought it down .4 mils for a new cold bore zero.

Target 6 was a hot barrel, after cold bore zero. Just very surprised at the larger shift in POI cold to hot.

 

[Maxduty]

If it's a thin barrel hunter, honestly, that's normal. Heat stresses showing up in the barrel. You'll notice that shot three is roughly were the group center on the next target is. But there is a lot that could be going on here too. Show me a pic of your rifle.

 

[Vandy321]

It's a proof sendero.

I guess I'm ok with it as long as the cold bore shots stay consistent. But may have to find the issue or build another rifle for running warm/hot for steel, since I want this rifle cold bore zero'd for hunting.

 

[Vandy321]

If it's a thin barrel hunter, honestly, that's normal. Heat stresses showing up in the barrel. You'll notice that shot three is roughly were the group center on the next target is. But there is a lot that could be going on here too. Show me a pic of your rifle.

 

[Quest1000]

What caliber is it?

 

[Vandy321]

What caliber is it?

300wm

 

[Maxduty]

I'd guess the barrel is heating and moving if you're not flinching. The verticals can be ammo, the horizontal is gun, shooter or wind. Try turning the scope down to about 6x and reshooting it. This should eliminate one variable.

 

[Vandy321]

I'd guess the barrel is heating and moving if you're not flinching. The verticals can be ammo, the horizontal is gun, shooter or wind. Try turning the scope down to about 6x and reshooting it. This should eliminate one variable.

Rog..but what does turning the scope power down eliminate as far as (I'm assuming) shooter error?

Those 3 cold bore shots, when measured from POA are about touching. Just trying to understand why when I re-zero'd after those cold bore shots and reduced cooling times, POI shifted low and right by almost 1" each direction

 

[Maxduty]

Your pic shows your scope at 20x. I think your crosshairs may be dancing when you try to shoot and you're pulling the shot. Fundamentals can play a large part here too. if you're left of the gun, it will jump right. But I think there may still be heat stress influencing your barrel.