If you can do it, get the 7400 Synthetic Carbine in .30-06.
Don't worry about the 'J'-lock at the moment; it might be no big deal or be replacable.
The rifle I have has been an excellent example of this gun, and I, too, wanted a general purpose unit. It was and is a good choice.
Sure did raise some eyebrows at the range!
The guys would 'whip out' various .223 & .308's; then I'd pull out this little guy with the Harris bipod attachment and bipod on it; too big of a scope, etc.
(I didn't mess with the 10-rd. mags there. I later found out they'd make better targets than magazines...use the factory Remington mags...)
All of a sudden there was a "Little Big Rifle" sitting there! Fun? YES!
One of my favorites.
"This is the 7400 & 870 setup for "Y2K".
The 7400 is a Carbine/Synthetic stock .30-06 w/18.5" bbl.
The buttstock is a Choate for the 870...filed down a little to slip into 7400 action.
The factory Remington 4-rd. mags fit & function the best.
The scope at the time: Leupold 4.5-14x40 w/Redfield JR base and low rings. The rear sight was moved forward up the ramp for clearance.
This rifle has been totally reliable and accurate with both 180 & 220 gr. ammo from Remington.
The rifle has since been returned to standard configuration with a smaller, lower powered scope."