Lefty guns and good calibers
 

I currently own a left handed ruger m77 Hawkeye in 30-06 I am looking to buy a new rifle what caliber ? And what brand. Normally I hunt deer and elk the deer around 100-400 yard shots elk more around 200

Seems to me that you already have a rifle for that ?!?!

You want one more for deer, or more for elk; or maybe bear or something to shoot dogs and cats with ??

buy a used remington 700, have it rebarreled, its what I do

or have them built



RR

Yes I own a 30-06 but have an option to buy a 300 win. Is the 300 win that much better?

Proven fact all things shot with magnum calibers stops the heart .005 seconds faster. Looked it up on the internet.

At the ranges you're talking about, you won't notice a difference in lethality, just the cost of the ammo.
Stick with the '06. It's cheaper to shoot, less recoil, making it easier to practice with. More practice will make you more successful than just upping the power of the cartridge. You can't miss them fast enough to kill them.

Ain't nothing wrong with the old '06 for your intentions. But on the other hand, there's no reason not to get another rifle if you want to. The 300WM will only give you a couple hundred fps in bullet speed and some more KE. But with a well placed bullet no animal is going to know the difference.
If you are looking for another rifle why not go down and get something like a 7mm-08? A great deer cartridge and although IMO minimal, can be used for elk.
As for production guns you have far more choices than us old timer lefties had. Almost every major manufacturer makes a left hand version of their rifles. I personally have a preference to Browning and Tikka.

After many many years of "justifying" the reason for this rifle or that rifle to the boss (wife) I have become somewhat of an expert in "justification".Now, it seems to me, that you just want a new rifle. Something different. Because in all reality, you have the perfect one for your needs. The .30/06 has more than enough "horsepower" to take anything on the North American Continent. Even the Brown Bear with the right load. Factory ammo is plentiful and also has MANY different loading's to meet different needs. My own personal opinion of the 300 win mag is that it's not needed at all. (Yes I do own a barrel for the TC and also a bolt but that doesn't in any way mean I NEEDED them) As long as you limit your range on Elk to 300 and under, a quality 160+ grain pill on top of a .30/06 cartridge is all you would ever need. But far be it from me to say NO DON'T DO IT! Because some people just love to get the hell knocked out of them at the range by the magnums. Some people love to pay outlandish prices for ammo. The .300WM is a long range cartridge. Plain and simple. People seem to think that it's some magical answer to poor shot placement. Or that it is some magical answer to being able to shoot past their limited range abilities. It isn't. I can load up a .30/06 cartridge to pretty much match any factory loaded .300WM and in 2 of my .06 rifles I can range with ANY .300WM factory rifle at 1000 yards. The .300WM is just an overrated magnum just like most of the others.

reguardless of what the naysayers post, cubic inches makes horsepower, at the far reaches of a rifles capabilities, yes the 300 winny is that much better. my overated 7mm Allen Magnum will run a 160 accubond at almost 3600 fps, that amounts to a lot less clicks up at a grand than the 280 rem, or the 7mm mag, the less you haveta spin the knob or estimate using a BDC, the less chance for a screw up. and the more energy you deliver on target, to 300 yards you will see no difference.
RR

Not very many people attempt, or SHOULD attempt shots out there past 300-400 yards RR. You know that as well as I do. Not everyone practices anywhere NEAR the amount of time they need to to deliver a kill shot rather than a gut shot at extreme range. Most people don't even have access to ranges further than 200 yards for practice. I do, you do, and a few others do. And like you said, to 300 yards, you won't see any difference at all. In general, most any rifle nowadays will outperform the person. At reasonable ranges, he was asking if the .300WM is that much better. In my mind, a reasonable range for the average, hell even better than average, shooter is 400yds MAX. 300 for most. And at that reasonable range, the answer is nope it aint that much better. More expensive to shoot? Yep. Hell on the shoulder with most factory rifles? Yep.