1:8 5R progressive gain twist is the best. Cyphertext knows.
I'd like to know that my choice would be more than a weekend toy.
1. Determine your overall budget. AR-15's can become a never-ending $$$ black hole. Make sure you include:
- Base price of rifle.
- A case. You'll need something to transport to and from the range.
- If the rifle does not include them, old fashioned "iron" sights.
- A sling.
- Extra mags.
- Ammo. Pointless to blow your wad and not have anything left for ammo.
- Cleaning kit.
This gets you to the range and plinking. There are lots of options to fit your overall budget.
2. Close your eyes and envision the AR-15. Purchase a factory complete rifle that is equipped as many features you envision that fits within your budget.
3. Purchase a factory complete rifle from a well known large manufacturer, that is financially stable, who has the resources to back up their warranty. S&W, Colt, Ruger, Sig, BCM, etc.
Optional / Eventual:
A.) Trigger upgrade. This is one of two of the most useful upgrades to a rifle.
B.) Red Dot Optic. Since your goal is "not a weekend toy", you'll most likely mount an optic. This means Aimpoint, EoTech, Trijicon. A proven quality optic is one of the two most useful upgrades to a rifle.
Cleaning Supplies:
Cyphertext can validate. I was an obsessive cleaning nut-job. I bought every darn tool, solvent, lube, grease, etc. Nowadays, I use an Otis flexible rod cleaning kit, a bore snake, Breakfree CLP, cotton patches, and rags. I learned my lesson. I keep it quick and simple now.