What causes a 30gr bullet to tumble from a 22 hornet

[Fassteel]

For a couple years I thought I had a super good load with the Berger 30gr bullet in 22 caliber.
last time I was at the range I'm getting a key hole at 100 yards.
Perhaps I should test all my loads for tumbling...?
thanks FS

 

[Longwalker]

On Bergers information site: "Recommended Twist Rate: 1 in 15" or faster" If your rifle is 1-16" twist, like most are, perhaps you were fortunate before and things just reverted to normal?

 

[Fassteel]

perhaps it needs to be heavily fouled, to shoot well in a 16 twist, thank you Mr Walker

 

[joehunt]

Temperature and altitude will make a big difference as well.

 

[Ganderite]

Differnt lot of powder and slightly slower?

Try 1/2 gr more powder.

 

[sfp]

Had a 22-250 that would key hole when it needed cleaned.

 

[nowarningshot]

Its obviously not stabilizing the bullet. Too slow a twist rate in barrel, too long a bullet......long bearing surface. Not remembering the op, is it a monometal or other long length target bullet?

 

[mbogo3]

Is it an older Hornet with the .223 groove instead of .224 ? I had a Sako that would pattern .224 bullets all over the map.As suggested maybe up the velocity a little and see if it smartens up.