I have made a couple trips to the range trying different stuff.
The VLD chamfer does help seating consistency a bit.
I could see no difference at 100 yds with the rifle bedded under the chamber, but I don't think it will show up until 1000 yds anyway.
I messed around a bit with WLRs, and was excited when I got two consecutive ES of 12, but it didn't repeat on the next range session. In fact, I got one ES of 40...........
However, I think my chrono may be the culprit. I know a chrono shouldn't "wear out", but this is the second time I have experienced something like this with a chronograph. It is getting fussy about light conditions where it didn't used to be. I don't know if there is a coating or material over the sensors that breaks down over time. I am also sure it didn't like getting rained on the one or two times I couldn't immediately grab it before the rain started.
This ProChrono is 6 years old and I have used it a lot. Two months ago its velocity average was within 4 fps of an Oehler 35p placed immediately behind it. The Prochrono was 10 feet from the muzzle and the 35p was 15 feet. I corrected the velocities by 10 fps for the Prochrono and 15 fps for the Oehler. I know the actual velcity change is an algorythm, but 1 fps per foot is very close. Most interesting was how the Oehler showed 4 fps less ES than the Prochrono for that 5-shot group.
Anyway, I need to get a new chronograph before I'm going to be able to confidently analyze my ES, and I can see no point in getting anything other than the Oehler 35p with the 4' rail. It runs $395 set up like this, and I hope to get one the end of April.
For my next match on 9 April, I am going to use my standard load of 51 grains of H4831 SC, Fed 210M primers, brass shoulders pushed back .001", necks .0155", .292 bushing, and bullets seated .010 from the lands. (This used to be right at the lands but the throat has eroded away another .010, but that depth is still where it likes the bullets.)
The only things I'm doing differently are:
- Using a newer set of fired cases, the ones I used the VLD chamfer on, and ones that I think I got more consistent necks on
- I now have the stock bedded 2" under the chamber
- I will uniform the metplats of the bullets
Also, I noticed my scope ring cap screws needed tightening a bit after the last natch. The scope wasn't loose, but I had torqued these to 37 in/lbs when I installed the scope, after lapping the rings. I had to retorque them more than I have ever had to do before. The bases screws and ring to base screws were/are still tight. I ahve never used Nightforce rings and bases before, but the rings have a very small top cap. Now this rifle doesn't kick much, but the scope does weight 2lbs. Perhaps the rings just needed to be retorqued after a few firings.
Regardless, I will check them before each match form now on. My groups at the last match were 7ish, 6ish, and then 10ish. I can't help but wonder if the loosened ring screws contributed to this.
Once I get the Oehler and tweak for ES, there won't be much benefit for me to do any more 100 yds testing unless I make a big change. I am going to try WLRs again, Russian primers again, as well as CCI BRs. I may even give H4350 another go.
