Hi everyone,
I have noticed something very peculiar with my rifle and I need your help. I have been reloading my own bullets for my Sako Finnlight 75 .300 Win Mag for about 6 years now, but lately I've noticed something that has me concerned. Ever since I changed from loading 165gr Nosler Paritions to loading 180gr Nosler Partitions it seems that if the same shell is cycled in and out of the chamber enough times that eventually there is a specific orientation that causes the side of the bullet to contact something in the chamber or barrel of my rifle and it "scuffs" the bullet. If I simply rotate the shell a tiny bit it will no longer hit anything and the bolt closes smoothly and easily as it should.
I've tried seating the 180gr bullet at various depths with the help of my RCBS Micrometer Set to resolve this issue, but this weekend I noticed that it's not the ogive that is hitting (which is what the micrometer measures), but rather farther back on the bullet not too far in front of the top of the casing (maybe 3/16") where the bullet is pretty much flat on the side.
I have made sure that the casing isn't hitting, and I never had this problem with 165gr Nosler Partitions which were seated much farther out of the shell such that they were only 0.010" off the lands. I am now about 0.050" off the lands and having this "contact" issue, so I'm certain it's not the bullet contacting the lands of the barrel but rather something else in the chamber/barrel.
Any advise or insight would be greatly appreicated.
-Trevor