First, the rifle and ammo
Rifle: Norinco M14S
Ammo: 168gr. SMK over 36 and 36.5 grains of IMR4895, CCI no.34 primers, once fired full length resized Hornady 308 Win brass, COL of 2.800''.
Now, pertaining to the fired brass, I noticed a ridge that forms on the shoulder of the case that forms a ring going around the shoulder. Should I be concerned by this? Is it indicative of a chamber cut with poor or worn tools? Is it something else? Will this stress the shoulder more during resizing causing cases to be good for less firings? I now M1As/M14s are hard on brass to begin with and damage brass in 3 to 5 firings. Here's a picture. None of the cases are cracked.
I have noticed the primers seem somewhat flattened? This is weird because those are basically suggested starting loads for IMR4895 over 168gr SMKs. Pictures:
Could it indicate head space issues?
Also I'm getting wildly inconsistent groups. I thought I was pretty consistent in brass prep, powder measuring and bullet seating. Cases were trimmed within 1 thou of the 2.005 recommended in my manual, all charges were spot on on my digital scale so + or - .1 grain and I used a Redding competition bullet seating die. Here are four groups shot with 36.5gr of powder.
Is this typical of working up a load or do I just have a bad barrel? I'm no Todd Hodnett or Chris Kyle but I'm not that bad a shot either. I could get consistent .75 to 1 moa groups with my Rem 700P with commercial hunting ammo. Now I understand this is no bench rest rifle either but I figured using quality components assembled in a consistent manner would yield better results.
So what do you guys think?