So I've been working my way up with some 308 loads using imr 4064 and Sierra 175gr SMKs. I feel like I'm getting closer to a nice accuracy node as I approach 43.5gr. Groups have shrunk about a half inch. However, at 43.2 I'm getting some fairly heavy CHS although ejection is right at 3 o' clock. In my bolt rifle I get zero pressure signs with the same load. I read in a few places that most AR 10s will do that with heavier bullets. Since I don't want to install an adjustable gas block I was thinking about adding weight to the buffer. Does anyone have any experience doing so and/or do y'all think it will help ?
I'm going to start by swapping just one steel weight for a tungsten one which will add roughly .9 oz. If it runs well I may even swap the other steel weight too adding almost 2 oz to the buffer. Here is a picture of the CHS marks from the 43.2gr load.
I'm going to start by swapping just one steel weight for a tungsten one which will add roughly .9 oz. If it runs well I may even swap the other steel weight too adding almost 2 oz to the buffer. Here is a picture of the CHS marks from the 43.2gr load.