Much depends on the measurements/constrictions and where they are situated. It sounds as if everything should fall back to the breech.

Ross' rifled sections sounds to me to have a bore of .690"(bore of the rifled choke) and the groove diameter of .736". That's how I understand it - right or wrong. I'd like to know for sure, obviously.

The Paradox muzzles I've seen appear to have very deep rifling which would match my supposition on bore and groove diameters - lands of .023" height/depth. .736" - .690" = .046" divided by 2 = .023".

I can't see the point of having a smooth choke section ahead of the rifled section (which must be tighter yet). If the choke was .715" for instance and then .690" for the 'bore' of the rifled section, the depth of groove would be only .715-.690" = .025" divide by 2 = .0125" depth of rifling, which does not sound sufficient to spin a 1,000fps 700gr. bullet, but maybe it does.

The smooth choke section merely makes the bullet to reduce in overall diameter by drawing down in size which causes lengthening and lead flashing off the rear edge - before it hits a futher reducing in rifling, but only by the lands. A bullet collected from a 'trap' might be quite interesting to measure - for it's 'major' diameter. Is it the original bore size (.736"), or a smooth choke size -(whatever that is)? how 'deep' is the rifling at the muzzle. That should tell whether the bullet is drawn down before it hits the rifling or not.