Originally Posted by BrentM
Is bolt lift your only indicator of max charge? I guess people have different methods but to me that is only 1 of several indicators.
If you have time take a pictore of the base of a case at max load for us, with spent primer, etc still in place. I would like to see how much if any brass flow you have.
No. With 4831 the primers have been flat since about 49 grains. At 52.7 the bolt lift gets firm and you can see a light ejector mark and scraping of the back of the case from lifting the bolt. The primer is NOT puncuted or cratered though. Other than being pretty flat the primer is ok. All these together tell me I really don't want any more 4831. I did zero it at 200 yards today and one shot had what I would call "nearing heavy bolt lift" but the others were just firm. Again all these factors tell me I'm very near max for 4831.
Retumbo is different. I haven't messed with retumbo since switchiung back to 4831 a few weeks back. Before going out to zero it today I took 6 rounds that I had previously loaded with 57.3 grains of Retumbo at different lengths. These were shot left over from when I was shooting test groups. If the first three did not group at all I didn't bother to shoot the other two. So i took 6 that were leftovers, all with 57.3 grains. I gave them a good whack with the bullet puller and seated them back with the seating die set at my current length. Now, a couple of the rounds came completely undone and a few pellets of powder fell out of the bullet puller. I reseated these anyways to shoot because I wasn't going to reuse the powder anyways. Like a dummy I did not keep these rounds seperate because I was in a hurry. After zeroing at 200 with the 4831 load I shot these 57.3 grain Retumbo rounds. I'll explain the pic. 5 of the shots I know I was center of the bullseye when the trigger broke. 1 shot I was tiring and when the trigger broke the crosshairs were about 1/2" low and a 1/4" left. 3 shots grouped well. Approx. 1/2" ( have not measured YET and rember this is 200 yards so that's 1/4 MOA roughly) and one shot is 1/2" lower and a 1/4" left of the group. ( just like the one shot broke) and 2 shots hit high. I'm assuming those are the 2 rounds that lost a tiny powder. Remember also that these are rounds I knocked out and reseated so neck tension is probably not as uniform as ussual. The recoil is less with the Retumbo and bolt lift is very easy, near no scuffing of the brass on bolt lift.
Now. I did not measure or take a picture of the 200 yard zero with the 4831sc because I was zeroing and making adjustments so it appears to be a terrible group. In reality If I moved the turrets a 1/2" the bullet moved 1/2" on the money. After the adjustments the shots stacked at about 1/4" at 200 yards. I am super happy. This will be my hunting load for now, but the Retumbo showed great promise.
I will take a picture of the 4831 52.7 grain brass and the Retumbo 57.3 grain brass later and post them for you. I was so happy with the grouping that I forgot earlier. *NOTE* This picture should be rotated 90 clockwise.