Hey guys - this probably seems like a silly question, but bear with me.

I've been wanting to dip my toes into some medium-range / precision shooting (my club has a 300-yard range and another nearby range has a 600-yard range). My natural inclination was to go with a platform I'm very familiar with, the AR15, and pick up a 6.5 Grendel upper for it.

HOWEVER, I then realized that I already have a Savage model 11 in .243 Win sitting in my safe that's been there for probably 15 or more years. It was a rifle I bought to introduce my kids to shooting when they were younger. It wasn't anything special - just a package deal that I picked up from Bass Pro. It has a mossy oak camo stock and cheap Simmons 3-9x40 matching scope and a thin (standard?) profile barrel. It does have the accu-trigger, which I always liked.

My question: should I go with the 6.5 Grendel upper for the AR or am I better off putting a little money into the Savage in the form of a new stock (not a fan of what's on there now) and some decent glass? I'm not looking for 1-hole groups at 300 yards, but I definitely want something with good accuracy. Is the thin-profile barrel going to be a weakness or am I overthinking it?

I'll be reloading as soon as components are available again (I reload my handgun calibers, but haven't reloaded rifle in many years, so I don't have any components or tooling for it).

I appreciate your opinions. It's a new area for me, as I've spent most of my shooting experience with handguns, PCCs, or AR/Tavor platforms.