That is true, but my renegade won't shoot a prb , if you do , it curves really bad. So sabots are the best choice for it.
Must be the 1:28 twist barrel

I shoot Hornady .40 caliber 180 grain XTP and HAP bullets with .40/.45 MMP sabots in my .45 TC Hawken with 1:48 twist. They shoot quite well. The longer 200 grain SSTs and SW bullets do not shoot as well as the shorter 180 bullets.

Therefore, I would suggest that you try the shorter, lighter bullets, as opposed to the longer heavier ones, in view of the relatively slow barrel twist.

Try using the barrel the gun came with. Mine shot 2" groups at 100yds with PRB's. Plenty accurate enough for hunting.

that is the barrel the gun came with, at least when I bought it from someone on here. Now as far as the factory barrel , well I wouldn't know about that since I am not the original owner.

I can't argue with that Muley. If I were never going to shoot farther than 75 yards I could probably live quite comfortably with round balls only. But even at 75 yards a sabotted bullet gives you more shot angle options.

The Renegade barrel should have a 1-48 twist. Not ideal for a RB, but better than what you have.

Did you make a typo?

I would guess a 1:48 twist that does that with a decent hunting load is the exception, not the rule.

Roundballs will be my first option followed by buffalo ballets, then a conical - maxihunters or maxiballs - will see what she likes and go from there

No, no typo. I bought it from a forum member and it didn't have a factory barrel. It had a GM 1:28 twist 45 cal barrel on it. I knew that before I bought it of course.

That explains why it doesn't like a PRB. Your barrel was made for modern ammo. It's like shooting a PRB in an inline. It sort of works with light loads at short distances, but fails with hunting loads.