Test Data on Annealing / ReHardening
Been busy with some other projects. Finally got back to this one.
Goal: compare seating forces between
a) new out of the box Hornady .308 match cases FL sized to 7mm08
b) used many times, annealed many times, annealed, shot, resized; initial and after successive resizings
c) lightly annealed new Hornady .308 match cases FL sized to 7mm08 (2 cases)
d) overannealed new Hornady .308 match cases FL sized to 7mm08, initially and after additional successive resizings (2 cases)
e) A commercial loaded round disassembled and tested.
I attempted to use a bathroom weight scale, the Wilson 7mm08 inline seating die, and an arbor press to measure seating pressures. Getting the stuff inside the gap of the arbor press was problematic. Using my weight directly on the inline seater, I reached 120 lbs. and STILL could not seat a bullet.....I gave up and went back to using the homemade spring strain gage at right angles to the Lee handle, crudely calibrated. (See photo)
Group B was one of my many-times used cases that shot low in a recent test. I re-annealed it to maroon, tested, then resized/re-colleted, measured seating force, and repeated (3 total sizings and measurements)
Group C was annealed to maroon and tested.
Group D was intentionally "over-annealed" past "maroon" to definite RED (but not orange) color. This is how I might have annealed cases when unsure of whether I'd seen the color change. You'll see these results are DEFINITE
Group E was a Fusion 120-grain commercial loaded round, with a cannelure, kinetic disassembled, deprimed, lubed, sized, chamfered, collet sized (my standard procedure at every point), and then bullet seating pressure measured.
======================================================
RESULTS -- APPROXIMATE SEATING PRESSURE FOR FLAT BASE SIERRA 120GRAIN SPIRE POINT BULLET AT END OF HANDLE OF LEEE PRESS
Group......................A.........B.........C.............D..........E
..........................NEW......TYPICAL.ANNEAL...OVER,,,,,,COMMERCIAL
..........................CASE.....ANNEAL..NEW.......ANNEAL...ROUND
TEST #
Initial....................5#........3#........5#,5#......1#,2#.....2#
2nd......................X..........4-5#.......X...........3#,4#.....X
3rd.......................X..........5#..........X..........4#,6#.....X
X means test not done
=====================================================
My Conclusions:
1. The commercial round appears to be softer than I would expect, maybe that is because they are using cannelured bullets and likely crimping.
2. ANNEALED TO RED CASES ARE DEFINITELY SOFTER AND AS SHOWN BEFORE, SHOOT LOW IN MY GUN! Re-sizing them multiple times appears to bring them back to reasonable hardness -- big result!! -- at least three times needed in my test.
3. Annealed new cases to just barely color (maroon) appears to have minimal effect; annealiing multiply used cases gave an intermediate effect (3#) -- probably shows inconsistency in either brass, or more likely, mytecnique. Re-sizing one more time returned those cases to the range of "normal".
P.S. My TempiLaq has arrived. Another opportunity to learn!
