I noticed that Noveske is using CMT bolt - and it comes with blue insert and a rather normal looking spring like the typical CMT offering ( i didn’t count the coil so here is just an assumption). Do you guys find the need to replace it with black insert and colt spring? It seems to work fine but the ejection doesn’t appear to be as vigorous as the LMT.
All of John Noveske’s rifles are GTG from the factory. Don’t sweat it! 
I have left mine stock.
May depend on the barrel gas system as well. Mid-length gas systems are fine with the blue insert.
YMMV.
No, I don’t feel the need to replace it at all on the onset. I do feel a need to base my maintenance on round count and how the weapon runs. When in doubt, I’ll change out quality parts, but I wouldn’t worry about swapping them out when new. Everything wears out eventually.
If it makes you feel any better I ran my Noveske N4 low profile carbine (complete factory gun) at Pat Rogers’ 3 day carbine course this weekend, fired approximatley 1,200 rounds, I went into the course with a round count of approximately 400 rounds on the gun, the gun has never been cleaned (just add lube) and I have never had a single malfuction with the gun of any sort.
From 1997 - 2006 ALL of my guns had a Wolff extra power extractor spring and blue insert (no Defender thingy or black O ring) and I never had any extraction problems (97 - 01 I shot on average 5,000 - 7,000 rounds (.223) per year…from 2001 - 2006 my avererage was over 10,000 rounds per year).
And the N4 carbine wasn’t “babied” in class:
My suggestion is to shoot it until it needs to be changed (5,000 rounds) and change it out with one of Bravo Company’s spring packs (5 coil spring, black insert, and black O ring).
Just my .02
S/F,
Jeff
I am fairly certain that Noveske does not use Stag bolts.
If you want to upgrade the extractor components, get the BCM upgrade kit.
C4
I left the blue insert and factory spring in my N4, and I don’t have any extraction issues at all. I get a nice neat pile of empties at about 10’.
It doesn’t fling the empties like a Valmet, but that’s ok, I don’t have to look as hard for them.