How many rounds are put through before the weapon leaves the factory? My new M&P 10 appeared to be a little to dirty in the action bolt area. Plus a little bit of wear on the bolt itself. Seem like maybe 100 rounds went through before I got it.

Coulda been the shop you bought from?

I was thinking the same thing. He swears that no one from his shop fired it! Insisting that it came from S&W that way. I have my doubts about that.

Typically two. In states that require it, (as it was related to me by an ATF agent) one spent case is saved for tool mark information tied to that serial number, and one spent case is included in the package with the firearm.

Of course, the ATF guy could have been pulling my leg with the tool mark identification thing.

I think the retained case happens with handguns but not with M&P15s. I have three and none had a case included. My S&W revolver did have a case included.

Ya i havent bought a rifle with a case, but every handgun ive bought has had one included

my s&w 1911 had a spent casing included, i figured that was to show me that it was fired and the case wasn't distorted or damaged... though they didn't say where the bullet went.

my m&p-10 didn't come with a spent casing, and neither did my m&p-15. my m&p-15 must have been cleaned at the store as it was on display and looked pretty when I got it. I was at the store when they opened the shipping box the m&p-10 was in, it was full of heavy oil and had a fair amount of carbon in the bolt when I cleaned it. After i cleaned it i went out and put 20 rounds through it and then cleaned it again before putting it away and i don't think there was as much carbon from that as when i cleaned it the first time... but maybe it was just spread around more and harder to get rid of with all that oil in there.