Yeah 20" will do fine, I built a 19" 300 Norma Mag ai for out to 1k.
Sending 225 eldms at 2750 is plenty fast for expansion at 1100 yards.
I also have an 18" 7-300wsm improved and get 2800 with 180s.
Run your numbers and figure the max range you'd like to reach with 1800 fps impact velocity.
There's nothing wrong with a 7mm if it's just a want, it's not going to do anything better than your 300 prc though.
If you're going suppressed recoil between the two cartridges is negligible unless you're going ultralight.
Whatever you do get the shortest barrel possible, I consider 20" too...
You're making a lot of assumptions..
I'm not against using a lighter recoiling rifle, but it's getting pretty annoying seeing everyone go with the smallest lightest cartridge combo possible just to prove some sort of point.
If you're into that well cool, but don't make stupid comparisons about...
I run a Nomad LT on a short barreled 300 Norma Mag AI and its incredible how quiet it is, I'm talking more comfortable than my 10/22 without plugs.
I shot my buck with it the other week and the doe he was tracking literally just looked around for a minute and kept eating, it was unbelievable...
In that case the 7 prc is your best choice,
I only handload so I'll never own one.
I run a 7-300 wsm improved with an 18" barrel for my suppressed light weight setup, it's good to 900 yards.
My advice is keep it short whatever you go with.
Yeah it is, I've personally shot one and it surprised everyone in the group how quiet it was.
And it's just as repeatable as any TBAC, we tested that too.
If 6 oz is worth twice the price then that's the only reason to go with an ultra 7.
Only two things matter, length and girth..
If you're looking for a 7" can don't waste your money on TBAC get a YHM Resonator R2.
If you want max suppression and recoil reduction go with a Nomad LT or CGS Hyperion.
Another to consider is the Diligent Defense Enticer L