I have no intention of hot rodding this new Uberti 1886 rifle. I do not load myself, but do have some Buffalo Bore 45-70 +P ammo (as I also have a Siamese Mauser 45-70).
Uberti says 29,000 CUP is max, but I thought the newer Winchester and Browning 1886s exceeded that. Does anyone know if the Uberti is as strong as the newer Winchesters and Browning 1886s?

I don't know for a fact but the Uberti's should be every bit as strong actions as the new Wins + Brownings. I know that my Uberti Hi wall in 45-70 certainly was;but as you say,you are not going to hot rod it right out of the box. I have an original 1873 Trapdoor that I load for + I do load it light but I feel confident that I could increase somewhat,just never found it necessary.Again in answer to your question,I believe you will have no worries providing you are expecting this calibre to perform over what it is designed to do.You should start reloading;it is a lot of fun + thought provoking + the best part is that you get to "roll your own".Welcome to AR!

Actually I am not a new member. I was on for 10-15 years as WJM. But recently it said I didn't exist. I was never a big poster, just read and learned a lot. I am 70 and probably "fat fingered" myself out of existence.

hah, you ain't got to be 70 to pull that off.

I'm sure Uberti is using pretty much the same materials as Winchester is using in their rifles.

why not ask Buffalo Bore?

Actually I contacted Buffalo Bore and I just heard back from them (on the weekend!). They said it could easily handle all their 45-70 +P ammo. I asked them what I could expect in velocity in my 26” barrel for their 405 gr jacketed round that they say hits 2,000 FPS for a 22” Marlin. They said to expect 2,100 FPS. So it would have a ME of 3,967.

Great! Sounds like you are ready to go hunting!

BYW, how about a picture of the rifle?

First, I don’t pick it up until about Thursday

I will not receive it until about Wednesday or Thursday. I will try to post a picture then

Looking forward to a range report.

BTW, my latest boar was taken with my .45-70 double rifle and a Remington 300 grain JHP at 1545 fps. The first owner used the rifle for 10 years and shot many deer with that load.

Recoil is almost nil and accuracy excellent.
So, heavy bullets at high speeds are not needed for all game.