More testing today... with an interesting note that I didn't even think of. I loaded up some of the 124gr Lead RNs with 4.2gr WSF like I mentioned above, and I also loaded up some 147gr with 3.5 WSF to 1.12" OAL and tested them as well.
The unintended aspect of the test though... it was 82 degrees today at the range, however I left from work and my ammo was in a sweltering hot car all day. Easily over 100 degrees in the car. When I got the range I noticed several of the rounds had blue lube melting down the nose of the bullet (they were stored nose down / primer up in retail boxes).
After inspecting the rounds, and discarding the rounds with shown lube, the rest seemed normal and I continued to document everything.
So the report: May 1, 2012, Friday afternoon, 3:00 pm CST, mostly sunny, outdoors, 82 degrees (ammo left in 100+degree car for 6 hours prior to shooting). All rounds fired sitting, two-handed grip, with sandbag from 10yds range to target with ProChrono Digital in line of fire approximately 4yds from muzzle.
Atlanta Arms & Ammo: 147gr FMJ RN, 1.15" OAL
~ Used these as a baseline both through the chrono and for group on the target to compare the reloads.
~ One 10rd String, 1.60" Group
~ High Vel = 910; Low Vel = 841; Ave Velocity = 878; Extreme Spread = 69; Standard Deviation = 19; PF = 129.07
Batch 4: 124gr LRN, WSF 4.2gr, 1.10" OAL
~ Great feeling round, little smoky but not too bad, no failures to slide into battery.
~ One 10rd String, 1.52" Group
~ High Vel = 1048; Low Vel = 1004; Ave Velocity = 1029; Extreme Spread = 44; Standard Deviation = 16; PF = 127.60
Batch 5: 147gr LRN, WSF 3.5gr, 1.12" OAL
~ Great feeling round, little smoky but not too bad, no failures to slide into battery, excellent accuracy.
~ One 10rd String, 0.90" Group
~ High Vel = 878; Low Vel = 851; Ave Velocity = 868; Extreme Spread = 27; Standard Deviation = 9; PF = 127.60
The 147s handled GREAT, I LOVE them. They were super accurate, soft recoiling, great for watching the sights lift and return very smoothly. Depending on how the heat affects the speed of the powder, I may need to adjust the powder charge up a grain or so after running another batch through the chrono with better controlled temps.
So the questions... WSF is reverse temp sensitive, we know that as a fact. However, how much will it slow down from 82deg when heated up to 100+ degrees? Will it slow back down once cooled or is the powder damaged/slowed permanently? I will obviously need to reload a batch with the same settings and shoot them in better controlled temps to get an accurate reading on the speed / PF.
Thanks to everyone for all the help in developing these loads. I greatly appreciate it!
Very good thread!
This is good results and good record keeping. You are tright it is a entire hobby onto itself. The beauty is because of your other hobby this one just keeps on being important!
Good luck be safe.
RCG
