Thanks for your input. I assume you were with the Illinois State Police when they used the 39 and 39-2.
Since the alloy framed 39 could handle a steady diet of the +p+, I deduce that the steel framed 539 should handle them as well.
We didn't use the Fed BPLE in our 39/39-2. It wasn't until we went to the 439 that we started issuing the BPLE. Same alloy frame tho. We also used it in when we went to 459/469, both alloy frames. I don't recall exactly when we left the BPLE and went to the W-W 115 +P+. That might have been before we issued the 5904/6904, again, alloy frames.
I wouldn't have much worry about a 539. No doubt hotter ammo will cause more wear and tear than softer shooting ammo but I'm guessing it will take a lot of rds to wear one out.
I have told this story on this forum before. When we issued the 5904 (alloy frame) and the W-W 115 +P+ some people and depts were saying the 5904 would never stand up to the use of the W-W +P+. No one we talked to tho could tell us how many rds to expect thru the 5904. Just a lot of nay sayers. So one of our full time range officers at the academy decided to document rd of +P+ thru his issued 5904 and shoot it until it broke. Somewhere around 50,000 rds he replaced the barrel as the rifling was wearing out and it was losing accuracy. He replaced the springs but I don't recall rd count on spring replacement. When he retired he had documented 80,000 rds thru the same 5904 with only a barrel and springs replaced. He bought that 5904 when he retired and continued shooting it. I haven't talked to him in a number of years so I don't know if he's still shooting it or if he wore out before the 5904 wore out.
That's not to say any other 5904 would go 80,000 rds. His was not a hand selected gun. It was the rack issued, next one in the pile, issued to him gun. Could be had he gotten a gun just before or after that one he might not have gotten 20,000 rds thru it. Or maybe his was the lemon and the others could go more rds.
If a gun could go 80,000 rds, or 1600 boxes, then a guy has gotten his money's use out of that gun. If a guy could get Federal BPLE for $25/box he would have spent $40,000 in ammo. If my gun quit after that many rds I'd stick it in a shadow box with a plaque that read I'd just spent $40,000 and 80,000 rds to tear it up.