My hunting partner recently received a new rifle he had built by a reputable builder. A 300 WM with high end componets, Defiance action, Kreiger bbl, McMillan stock. I have the rifle and have done the break in and fired several load development groups. He does not handload so I typically hook him up with this service, he buys the beer in exchange. I noticed this weekend while carrying the rifle into my shop after shooting that something sounded "loose" in the action area. I shook it around thinking it was the mag box and realized it was the bolt. I put the rifle in my vise and started playing with it. After releasing the firing Pin the bolt has IMO substantial play horizontally, front to back. To my eye it looks like @ .050 movement. When you dry fire it the bolt visibly jumps forward. I assume this to be excess gap in the lug abutment area. To verify what that gap was I started stacking small cut pieces of duct tape on the front of the lugs and closing the bolt until the play was eliminated. I ended up with 6 pieces stacked on the lugs .036 thickness. It does not appear that the tape is contacting the barrel yet but the "play" feels similar to my rifles now. I put one piece of tape on the front of my defiance 338 Edge ant it bound up when I tried to close the bolt. The rifle acts like it wants to shoot with the few groups I have fired being sub MOA. My primitive test tells me there appears to be from .040-.045 gap between th lugs and the barrel (my test could be complete crap too) If this is the case what are the dangers? Will this adversely affect accuracy, what's will it take to fix it? And lastly is this a major eff up on part of the gunsmith or is it something that happens occasionally? I want to know if this is grounds for adding this builder to the BANNED list!.... Lol.