04-13-2017, 09:55 PM
Lastrites Wrote:I just had the opportunity to quickly look over a co-employee's 16" Grendelhunter upper he just received, the one that was on the close out sale. I noticed right off on this upper that the gas block appears slightly canted, coupled with the barrel possibly not being centered in the Strike Industry rail as it appeared to my eye. Also on that rail it uses 4 set screws to either lock the rail to the receiver or they assist in timing the rail square to the upper, doesn't appear have any lock-tite on the screws which I felt was odd as I certainly would have used it on those screws.
Bwtn the gb being possibly canted and likely the rail needing adjustment I am certain my future holds a tear down and reassembly of his upper. But I suggested to him to simply give it a complete cleaning, toss a scope and some irons on it and boresight it and we are going to run some ammo through it at the office.
Dgunnut, besides checking the obvious of loose screw/nuts and although you've only shot 100 rounds or so, do you think it's possibly you've had a build up of copper in the barrel? While a copper build up is a stretch with such a low round count, it's something to consider.
Mine was also on the close out sale awhile back. I will take a closer look at it to see if the rail is not aligned or gas block is canted.
I thoroughly cleaned it between the first and second trip. Don't recall if I used a copper solvent or not. Then I cleaned just the barrel between the 2nd and 3rd range trips. I specifically used a copper solvent at that time. Similar results during both 2nd and 3rd range trip.
I'm looking at swapping the scope back to another upper shooting that upper to make sure the scope and mount combo is Ok. I have the scope in a Burris PEPPR mount with the quick detach features. I haven't had an issue with the scope and mount before, but who knows...