I have a Remington Model 740 in 6mm Remington (aka .244 caliber). Yes, that's .244 and not .243. Remington goofed when manufacturing their original .244 when making it in a lighter 75 or 80 grain bullet. The lighter bullet was not as effective in dropping whitetail here in Texas and by the time Remington could retool and remake the .244 in 100 grain bullet, customers had fallen in love with the .243.
Now the .244 is called the 6mm Remington. It's faster, flatter trajectory and packs a better whallop than the .243. I've had a .243 and ended up giving it to one of my daughters for her children to shoot (after my youngest son grew up and 'graduated' to the .270). I've knocked a 2 yr old doe over with the 6mm and spun another around when trying to shoot a little late in the day and hitting her in the hindquarters. The round passed through leaving a tiny little hole going in and a quarter sized exit wound coming out. I can only imagine the damage done on the inside on its way through.
I'm just glad that I don't have to carry the rifle very far. Solid wood stock and forearm, its a heavy rifle for such a 'small' caliber. But I'm not complaining in the least. The rifle was my grandfather's and he bought it the year I was born. Let's just say that was more than just a couple of years ago.
My $.02 worth.