Thread: Tikka 300win mag - poor grouping 180gr Hornady Whitetail

It will likely be at least 1:11 twist which will absolutely stabilise 180's.

If it's that hot, you'll be getting mirage off of the suppressor and that will mess with your sight picture. Give it two minutes between shots to let it cool down. Get a fan pointing at it if you can.

Tikka's Sub MOA guarantee, for all it's worth, is a 3 shot group with premium factory ammo (which whitetail is not). Are you a capable of that? Have you got a good bit of glass on the rifle in a good set of rings? Do you have a good rest? When was it last cleaned? Have you tried any other 180gr ammo?