Couple of threads on barrel life this running in the Everyday Sniper section. For AR type rifles, (from my experience and research) range seems to be 2500-5000+. My first 224V gas gun barrel went to 2300 solidly at +-.75MOA, 300 more tossing occasional flyers here and there, and finally quit at 2800+ (turned into 4MOA almost overnight). BUT I ran hot, suppressed rounds for over 2000 of the 2800 rounds fired. Some estimates say suppressored gas guns can reduce barrel life by as much as 50% (which I tend to agree with).
On a bolt gun, I'd hazard a guess that barrel life would be much closer to 4000 min to 6000+ rounds. No gas port to erode, chamber/throat and barrel stay cleaner, so less crud to push through barrel each shot.
If you don't already have a trainer in 223 or 223AI, I think the 224V is a solid idea: cheap practice ammo from 75gr AmEagle is $10-13 a box (some getting 1/2 to 1MOA with this round), 88 ELDs can be purchased for .18-19 each for reloads and the other match loads are still around or under $1 per round. A 223 Wylde or 223Rem could be slightly cheaper to shoot but might be slightly more difficult to push to 800-1000yds.
My handloads (88ELDs @2750-2850) very closely match my 6.5CM drop/drift to about 700yds and, after that, I need to focus on much better wind calls. That makes 6.5CM feel significantly easier in same conditions.
So yes, a 224V bolt gun trainer can be a great tool: better performance than a 223, slightly better than 223AI and better barrel life than other larger case 22 Cal hot rods (22-250, 22 Creed, etc). I'm planning to build/buy one within the next few weeks for the reasons stated above and to compare bolt vs semiauto in this cartidge.
@reubenski beat me while I was typing; totally agree with him on brass and costs.