go .223 fast twist if poss .with the right load sub inch at 250 will be far better than factory ammo.more data and more reloading dies etc. top tip bite the bullet and get good gear first time round if possible.lapua brass is not cheap until you realise you can load it 20 times if the right dies are set up well etc.powder is not cheap untill you realise how many of those .223 bullets a 1 kg tub can make. as said already its as much a hobby as shooting if not more so.