Farmer Roy
I know exactly where you are coming from. I have been through this dilemma myself and reckon a T3X Superlite (synthetic) in 308 would answer your needs. I have a T3 243 stainless Varmint (topped with a swarovski 4-12X50)which I carry in the ute all the time, mainly for roos but the odd pig if it pokes it's head up. I love the gun and it shoots like a laser. The only drawback is getting it out of the window in a hurry when you need to get a shot off quickly. I recently got a T3X Superlite (which is stainless fluted in a synthetic stock)'
The T3X is shorter and lighter and I find a lot easier to handle in the ute or walk about with. The 10 shot mag from the 243 fits straight into the 308 which is another great advantage. I have a 3-12 X 50 Zeiss Conquest on the 308 which gives plenty of options for shooting at long ranges and snap shooting up close. I find the 308 a bit heavy on roos as they tend to hop off a bit, not realising they are dead, when I hit them using Buffalo River ammo with the 135gn projectiles. However they still end up dead, just have to drive a bit further, and no I don't bother head shooting them. The dogs don't care if their roo meat is head shot or chest shot
I reckon it is a great rifle for the job and I would shoot at something least 5 days out of every week so it is about functionality,accuracy and durability.
Hope this helps
Col