I recently had a chance to shoot a super 14 223 factory braked contender barrel.
I put one round through it and that was enough.
Even with ear plugs my ears were ringing.

I've been considering buying a 15" non braked or ported 25-06, 7mm-08 or 45-70 caliber barrel for my Encore or Contender and would like to know if anyone could tell me how they might compare to the near deafning, braked 223.

I have 10" and a 14" non ported .223 contender barrels. They are both loud but I've never noticed them being so bad I did'nt like shooting them.

One thing I might add to that though is that I did a pritty bad job of beating my ears up when I was younger shooting without good ear protection so I know my ears are much less sensitive tham most people.

I know exactly what you mean I would expect the 25-06 to have the same issues.

I'd think the 7-08 wouldn't be too bad in the muzzle blast, and the 45-70 shouldn't be bad at all.

Perhaps if you shoot at an uncovered range the short tube 223's aren't so bad, but on a covered range each shot feels like a concussion grenade going off in your face.

Braked 14" Contender barrels are wicked loud no matter what round they fire. I used to clear the bench area with a 7-30 Waters braked.
Any of the rounds you listed out of a 15" will be exceptionally loud given their length. A brake will make them worse.

Race Bannon?!! I loved your work looking after the Quest family!

Of course most of us are a little deaf already from shooting all those braked and unbraked pistols, handguns, rifles, shotguns, and muzzleloaders without "ears" so be careful of our subjective impressions. These days the Peltor 6S electronic hearing protectors are so comfortable and affordable there is no excuse for an unprotected shot, even in the field.

I am not a fan of ported anything for this very reason.
I have shot a 14" bull barrel Encore in .223 without the break and found it to be a little louder than a short barrel carbin in the same caliber. I did shoot an Encore pistol 7mm-08 with a break that hurt my ears even with good ear muffs on.

I use to shoot at a range in So Cal were you could back you car to about 15' from the shooting benchs and my 14"braked 223Rem would set off car alarms. The range had to shutdown last year. The word is a couple of the city counselmen wanted to build houseing tracks near the range. It was one of two outdoor rifle ranges within 40 miles of 8 million people.