A couple months ago I picked up a 200 round container of HSM linked 7.62x51 tracer. I am having second thoughts. Will a tracer round do harm to the barrel of a M1A if these were unlinked and run in it?
He's right...your typical distance that the magnesium alloy ignites is around 150-200yds. If you don't shoot that far, you won't even see it, but it will light after it impacts your target (something to take into consideration when you determine your target and 'what lies beyond'). Just read your range rules, and if you don't have any of those, just make sure not to shoot them into a leaf pile in the middle of August. If you want to be safe, just save them to shoot after a heavy rain.
One REALLY neat thing about tracer rounds is you can SEE your ricochet! When I was at the night fire machine gun range in combat training for the Marine Corps, they gave us each a belt of 200rds (lasted about 30 seconds of bursts)...but probably the most fun I've ever had with my clothes on watching the sky lit up with tracers flying upward and every which way with 20 Marines on the firing line.
I was coincidentally just going to put up a WTB ad for 7.62x51 tracer rounds to belt up for a 1919a4 project I'll be riveting together this winter. If you decide not to shoot, please consider putting me at the top of your list of potential buyers. I think this is is sellers market for ammo right now, lol.