Question on A-Max bullets in .243

[bohe]

I bought some 105 gr. A-Max bullets to shoot in my CZ 550(1-10 twist I think) .243.I don't have a Hornady book so I was using info for the Sierra 107 gr. MK bullet.The only powder I've tried so far is Varget.I now realize that my 1-10 twist might not work for these bullets.My first group was about 7"@100,but by the time I got up to the max load(Sierra)the group shot 2.5".My question is should I not bother with these bullets or should I keep upping the powder to see if the group tightens up?No pressure signs yet.Has anyone had a similar experience?
Thanks Guys

 

[Winchester 69]

Hornady recommends a 1:9 twist with this bullet.

Your CZ has a 1:10 twist barrel.

 

[davewilson]

forget the VLD's of 100 and over.