Well I finally got a chance to shoot my .300 today and break the barrel in. I somehow misplaced a round in my shooting bag and only fired 9 shots instead of 10
. I did my standard procedure of firing one or two, then thoroughly cleaning the barrel and repeating the process. I cleaned using a copper brush, Parker Hale rod, Hoppes Benchrest solvent, and ever absorbent paper towels, to dry the barrel and apply the solvent.
I only got the chance to shoot 50 yards because my range was packed with fools spraying away, and I was crunched for time. I wanted to sit up at 100yds after sighting in, but just decided to leave it at 50 since I was only breaking the barrel in and wasn't too concerned about a group. It isn't the tightest group, but for the constant stop and go with cleaning and some varying mirage, the rifle is showing promise. I just used the minimum load listed in the Nosler manual since I wasn't looking for velocity or accuracy. Also, I used 10 old 180 SMKs I found in a box downstairs, they were all blemished and dirty, but they worked and shot good.
My load:
-180gr SMKs
-69.0gr IMR 4831
-Remington LR Magnum Primers
-Winchester Military Brass
-C.O.A.L. 3.520"
The far right hole was my very first shot and was 8 clicks off, not bad for bore-sighting! The next 8 rounds landed inside one ragged hole. The group measured .557", not very tight for 50 yards, but with a brand new barrel and all the variables that went in with breaking the barrel in, I don't think it's too bad. Overall pretty happy with the results and excited to report that the rifle is showing promise!
I have 20 rounds loaded up with IMR 7828 and IMR 4831 with 190 SMKs for load development, I plan on shooting them for group and measuring their velocity over Dad's chronograph I got him for Christmas. I will try to get them shot and report back to you all as quick as I can. If these two powders don't get me to at least 3050fps safely, then I will be getting some RETUMBO or H1000 to try!