Big bore for hunting

I’m a very ethical hunter I’m not going to use a small caliber on large game and I’m not taking a shot over 100 yards. I want a 45 or 50 caliber which is plenty ethical, my buddys dad is a taxidermist and this year alone has had at least 10 larger bucks taking with air rifles. I just wanted some advise from people who own one that could point me in the right direction of a quality large bore. Just to add, in my state it says .30 caliber air rifle or up is legal for deer which in my opinion seems a little small but I’m not sure.
 
its really whatever you want .. id look for at least 900ft/s for long shots and if i was an avid deer hunter which im not, id likely get a 45cal .. but for your situation i hunt his as down with my bulldog and waste him .. id be comfortable on a head shot to 60 or so with it with a regular pellet .. i bought it to execute deer at close range, i hate the f'ers .. make my life dangerous on my bike and yes theyve cost me 1000'S in damaged property and broken bones .. no sympathy for those tick ridden parasites ... but with a donnyfl emperor and hill depinger its about the sound level of a stock prod ...
 
The word “Quiet” in regards to big bore airguns is somewhat relative. There’s a lot of sound from the hammer hitting the valve. And there’s a TON of air being moved. So it’s best to manage your expectations from the beginning. You might see videos on the Youtube showing a very quiet big bore being shot but that’s not how it sounds in reality. Silent they are NOT. “Quiet“ in terms of big bore airguns really means you don’t need ear protection. It’s still obvious to anyone nearby that something is being shot.
I’d say check out the TexanSS in .45 with the carbon fiber tank. It has as much power as my full size original Texan and it is a lot easier to carry through the woods and maneuver in a stand or blind with. And you are going to need a scuba tank and access to high pressure air. You are going to go through a decent amount of air and slugs learning your hold over for particular distances and getting the feel for your rifle. You do not need a massive scope. 3x9xWhatever is going to be plenty for normal deer hunting distances which are rarely more than 100 yards, and in my experience usually 50yds and less if you are in a tree stand waiting for the deer like you already have been doing for bow hunting I’m sure. 
You can’t go wrong with the Texan, but don’t underestimate the power. I wouldn’t shoot it anywhere near or in the direction of a neighbors house. The 3 or 400 gr of lead you are shooting carries a lot of power a long long long way.
Good luck on getting your deer and congratulations on deciding to go the most expensive route possible to do so. Hahaha