NB's 22 centerfire rule is the reason so many 22-250 & 223 rifles are sold there. You can't be in the woods with any rifle larger than a 22 centerfire once you've taken your deer OR after the deer season is over... There is also a restriction on the size of shot you can carry when out with a shotgun, #2 & smaller, if memory serves me correctly...
If I had to have ONE rifle in NB, I would buy a 223. I say this because it is SO UNLIKELY that you will ever get a moose licence!!! ***Just ask SuperCub... It's a once or twice in a lifetime crap shoot to get a licence for moose in NB!!! If a lightening bolt DID happen to hit you & you got a moose tag, you could borrow a rifle for the 3 day hunt... And don't get me started on that "3 day hunt"... What a joke that is!
Anyhow, back on topic... I have a Stevens 200 in 308, my wife has a Stevens 200 in 243, both with Elite 3200 3-9x40 scopes & BOTH shoot under 1 inch @ 100 meters!
So, if I were you, I'd buy the Stevens 200 in 223 & put the scope you traded for on the rifle. My last comment will be to echo what other guys are saying, USE APPROPRIATE AMMO!!!
If you don't reload & don't have access to reloading equipment through a friend... Make the effort to track down Winchester's 64 grain PowerPoint 223 cartridge that they rate for deer.
There are many guys in NB that only have one rifle. But, they commit the "Cardinal SIN" of using varmit rounds in their 223 & 22-250 rifles when hunting deer. I DON'T RECOMMEND IT!!! Hopefully someone will chime in here & comment on whether it is even legal to use a varmit bullet when hunting deer. I don't recall what the NB regs say about it.
Cheers
Jay