Shoot both barrels 500 times and then video them. You will be surprised that any barrel that is fire-cracked (both will be) will shoot well for a while. They do!
We have been randomly playing around with factory Remington rilfes for a couple of years. It started out as an attempt to see how thriftly we could get satisfactory performance. So far we have tuned new ones and used ones. To date, each and every one shot under .3 using tuned factory ammo. The only thing we did to the ammo was change the seating depth and boy what insight it was.
Using handloads with the sendero rifles, we got all the senderos under .2 except for one finnicky used one that remained stubborn at .375 (rifle bought used and had an unknown number of shots down the tube).
The point is if you are going to compete against fellow shooters that are using custom barrels, then you probably need one to stay competitive. However, if you are hunting and you are the adventurous type, you could tune a sendero to shoot better than most shooters are capable of shooting. Not to mention saving some bucks for gas and to go on some exclusive hunts.
All my guns are custom guns with custom barrels........... Except for one. It is a 24" Sendero Special 300 win mag with a muzzle brake that cost under $600.
Had I known that the Senderos would shoot so good when properly tuned ammo is used, I could have saved myself:
$12,000 on custom barrels alone.
$16,000+ on four custom long range rifles.
$7500 on scopes
I have probably spent way over 40K designing cases and generally tinkering around with stuff trying to squeeze all the juice out of cartridges and custom offerings in the last six years. If I could keep the knowledge I have and then hit rewind, I would buy factory senderos and bed them followed by good load developemnt and then go hunting.
Now, if you want a switch-barrelled gun then going with the custom action is a must. But after you factor in the cost of a custom barrel, chamer, crown and barrel threading, then you could have bought almost another sendero.
Lastly, if you are desiring a case that the remington action does not offer a bolt size to fit, then go the custom route. And, if you go the custom route, get a custom action that is more than just a remington clone that accepts remington parts. Get one that has some mass to it (A Bat would be my choice) and that is a custom action from the ground up. Also, if you decide to use a bullet that a sendero twist will not stabilize, then go the custom route as well.
But, I did have a good time tinkering with all that stuff.