Re: 308 vs. 243win
Well...
6 BR, 6 Dasher would be worth a look.
6.5X47L is also worth a look.
All these will give you better barrel life than the 243.
I for one think the .308 is the work horse can't go wrong versatility cartridge.
If you have specifics in mind you need to choose a caliber/cartridge specific.
Line out what your use is. Then decide.
food for thought ( copied from another site )
The 6BR -- What Does It Offer the Tactical Shooter?
Is the 6BR a good choice for tactical shooting? I think so. First of all, consider that many police "sniper" rifles are chambered in .223 Rem. Well, the 6BR beats that cartridge hands down in every respect (accuracy, energy, and long-range performance) except magazine feeding. Moreover, I've proven that, with a few simple modifications, 6BRs CAN mag-feed reliably. Next, compared to the venerable .308 Win, how does the 6BR stack up? In the "plus" column, the 6BR offers great accuracy, low recoil (55% less than a .308), high BC bullets, and the best factory ammo you can buy. The 6BR stays supersonic longer than the .308, it has a flatter trajectory than the .308, and its retained energy at 800-1000 yards is within 15% of a 168gr .308. In the "minus" column, when compared to the .308, the 6BR has much less energy at short ranges, there is no special purpose ammo (tracers, armor-piercing), and the short round makes it difficult to feed in most rifles. But again, that is just a matter of re-engineering the feeding system. There are plenty of 300m competition rifles that feed 6BR cartridges from magazine flawlessly.
Key factors, in my view, are the 6BR's low recoil and dramatically lessened bipod hop and muzzle movement. (Watch that Video to see for yourself.) Set a 6BR up with a good muzzle brake or suppressor and you can see your shot impact. That is very important for a real sniper engaging real targets. Being able to see bullet impact gives you immediate feedback, so you can correct for your second shot if necessary. When you combine the ability to see bullet impact with the intrinsic accuracy of the 6BR, you produce, in my opinion, a "better mousetrap".
But what about down-range energy? Plug the numbers in your ballistic program for both realistic .308 Win and 6BR loads and the difference narrows as distances increase. For example, at 800 yards, a 168gr SMK, launched from a .308 with 2700 fps muzzle velocity, has 769 ft-lbs of retained energy. In comparison, a 107gr SMK, launched at 2850 fps from a 6BR, has 665 ft-lbs of retained energy at 800 yards. That's only 13.5% less! (Calculations from Point-Blank ballistics software.) So let me conclude, I'm not saying the 6BR is "better" than a .308 Win, but I do believe the 6BR deserves a place in the tactical arsenal.
