I just bought a very very nice AR15 all ultra hi end parts. It was supposed to be a demo piece for a shop but someone blemished the Vltor-Mur Upper on the thing the forward assist sits in and so they couldnt use it as a demo. Got a screaming deal as a result on a AR that otherwise would have been unaffordable to me. The lower is a Seekins Precision 223 SP223. The rifle was unfired During the first magazine I got multiple failure to fire. First 3 rounds went w/o a hitch. Then the next 10 attempted shots were failure to fire. I checked if the bolt was fully in battery and that stuff since as a new gun I thought at first, maybe it was short cycling , but it wasnt...... as most rounds simply had a light strike indentation. near the end of the 1st mag the gun started working a little. And during the 2nd mag it took off and worked perfect. I followed it up with another 3 mags w/o any problems (20 rds per 30 rd mag) I had not brought any more ammo than that, as I wanted to focus on zero and then maybe a little break in. Rifle got a basic clean/lube by me before I took it to the range. When I got the weak hammer strikes , at first I thought maybe they had a softer trigger spring kit in there and its too light for my ammo (Federal 5.56 mm M193F)...? But then the problem suddenly stopped occuring.... The bolt and BCG are Black Rain Nickel Boron..BTW, not sure it matters. Weird. any thoughts?