I bought this rifle about a year ago and have loved it. I've bedded the stock, stiffened it with epoxy and fiberglass fibers, and weighted the back end. I've also lightened the trigger down to about 14 oz and put an Athlon Midas BTR 4.5-27x scope on it.

With the exception of the first 50 or rounds, it's only ever had my handloads run through it. I went through the whole process of developing my loads with ladder tests out to 400 yards, COL grouping tests, etc. Generally 1/2-3/4 MOA were standard if I did my part but realistically the worst I ever got was around 1 MOA before any kind of load development was done. Lately however, the best I can get is like 2-3 MOA using the same bullets and handloads. My rounds do shoot around 3300 fps and I shot around 1500 rounds through it before the accuracy went to crap and the last 500 shot over 6 days have been total garbage.

Things I've checked and determined to not be the cause:
Swapped on a friends scope to rule out any scope issues
Checked torque on the rings and bases
Ran the same brand cases after being freshly prepped
Tried Sweets 7.62 copper fouling remover
Checked the torque values on the bolts holding the action to the stock
Checked to make sure the bedding and stock hadn't cracked
Checked to make sure the barrel is still free floating
Weighed all powder charges to within 0.05 gr of each other
Shot my rounds out of my friends gun and they grouped well

I'm at a loss as to why my accuracy went to absolute crap. Surely I haven't burned out my barrel already...or have I? Any suggestions would be appreciated.