I have an Apex trigger and springs on my 5" M&P 9 Pro and I really like its performance, but I could stand to do a little better at 25 yards.

Right now, the majority of my grouping is around 5" and the flyers generally stay around 8 or 9". The target has a 2" bull, a 4" 10 ring, and an 8" 9 ring, so I'm keeping most of them in the 10 ring with some 9s and the occasional 8. Of course, I'd love to be getting all bullseyes, but 2" at 25 yards is pretty tough. I think 4" to stay in the 10 ring is realistic though, and something I could do.

This is all timed at 10 shots in 15 seconds, so I can't stand there getting the perfect sight picture for too long. In untimed events, I'm generally all in the 4" ring.

Anyway, I've noticed a decent amount of wobble in the barrel, and was thinking of getting a "match grade" barrel to see if that helped reduced my group size any. I saw Apex is making barrels now, but I guess they just started in December and I haven't seen anyone reviewing them yet.

Has anyone tried an Apex barrel in their M&P?

You forgot to do a search before posting ?? There been apex barrels discussions on going .

Link-
Accuracy is coming: Apex M&P Barrels

You got me, I did not search. I did read this thread back in November, but I guess I missed the updates after the barrel came out and a couple people talked about installing them.

I also found this thread while reading that one:

Accuracy is here: Fitting the Apex barrel myself.