Hardness question

[Calehedron]

Greetings,

I water quenched some Lyman 429421s that are cast from WW and 2%ish Tin on Saturday and I pulled them out of the water tonight. I have a Lee hardness tester and measured the dimple in 3 spots: nose, front band, and rear band. I got a .050 on the nose (20.9 BHN), a .064 on the front band (14.x BHN), and a .052 on the rear band (19 BHN I think).

I am leaning toward the 19 more since its on the rear band and almost the same as the nose, but how important if at all is the much lower front band hardness? Not too worried about since I normally just shoot AC bullets that are about 11-12 BHN most of the time. But I was just wondering...

Ken

[454PB]

Heat treated boolits need to age for a while to attain full and even hardness. Wait about 10 days, then repeat your test.

[MtGun44]

+1 on what he said.

Bill

[Calamity Jake]

There is also a correction factor involved for checking hardness on a convex/cylindrical surfaces from 1/4" to 1.5 inches dia. The correction factor number depends on type of material, diamater and hardness of test material.

[454PB]

The Lee tester instructions tell you to file a flat area on the boolit side for the test. I usually use the nose area, which requires less filing.

On heat treated boolits, I've filed deeply, up to 1/3 of the diameter, and found the hardness the same inside as outside.

[curator]

+1 on what 454PB said. Also when testing on a flat surface (not the rounded sides) you should do several (3 or more) tests without moving the slug. Testing for hardness compresses the other side of the bullet while you are making the test-dimple. If there are irregularities on the opposite side they will need to be compressed to give an accurate reading. I take several readings, throwing out the first few then taking an average of the others. The dimple-measuring system is sometimes difficult to interpret as well. I have a Lee, SAECO, and LBT hardness testers. The LBT is the most accurate, repeatable, and easiest to use IMHO.

Water drop-quenched wheel weight alloy with 2% tin added (what I use) has about 80% of its eventual hardness after 24 hours and a slow gradual increase in hardness for about 8 or 10 days. Sometimes an additional 2 or 3 BHNs

[Calehedron]

Thanks all for the replies. I have read anywhere from 2 days to 10 days for water quenched boolits to reach peak hardness. As I said before, its not a huge concern since I usually just shoot air cooled in my Redhawk but I was wondering about the front band being so much lower than the nose and rear almost matching ( almost exact if I was to take the CF into effect for the curve of the rear band). The Lee tester serves all my needs for now but when and if the hardness becomes a critical part of my shooting I will upgrade to LBT tester.

Cheers and happy casting!

Ken

[357maximum]

Thanks all for the replies. I have read anywhere from 2 days to 10 days for water quenched boolits to reach peak hardness. Ken




You do understand....the "WAIT" (cure) time begins after the boolits are removed OUT OF the water right? not saying you do not...but something raised my eyebrow a bit in your writings.



FWIW....I remove my boolits asap after casting and push through size them while still wet with the soapy quench water....then I can lube them in a .001 larger H&I die at my convenience. It takes about 1.5 weeks for my wd'ed 50/50 ww/pure to come up to full hardness.