This is hardly scientific so DO NOT do this and try to use the case afterwards.
I read a few threads about annealing and over annealing in last few weeks. A few posts got me thinking if it is possible to over-anneal a case head and if yes then how long does it take.
Just so we are on same page : different cases, different manufactures and even different lots will act differently so take this info with grain of salt.
I didn't wanna use a socket coz that would act as a heat sink plus I wouldn't be able to see when tempilaq melted. Also I wanted to create worst case scenario. I used 650 deg tempilaq coz I believe (just me, some people say 600)that's where brass starts to anneal. So I put case in Lee case holder and spun it with drill in the propane torch flame set to max with center blue flame just touching the case at neck shoulder junction.
First I did it with Lapua 308 case, I videoed it too. I'll try to upload but no promises as I have never uploaded video before so it may not work.
The picture is setup with tempilaq along the side & just above the case head (around the case)starting at 0.350" and finishing at 0.500" from case head(roughly). This is where I believed it's still supported by chamber but close enough to the head where if annealed I wouldn't fire that case again. I'm gonna call it "tempilaq belt"
Result: At full blast of "my" torch it took about 7 secs to melt tempilaq inside the neck(usually I'm done here) about 16 secs where case neck started glowing and 38 secs when I first noticed top of tempilaq belt staring to melt. I took 58 total secs where complete tempilaq belt was done.
I repeated the test with Winchester case, times were only couple seconds less compared to lapua.
Verdict: You guys come up with that. IMHO, this was worst case scenario where there was no socket acting as heat sink So unless you keep heating the case for another 15 seconds or so after case neck starts glowing(case is already not useable for precision work at that point) it is hard to dangerously anneal a case. Please don't quote me on that coz someone is gonna come along and prove me wrong.
Once again don't reuse such case, short cases will overheat faster and if you blow up your gun don't blame me, blame Mr Obama for that.
There you have it, don't over anneal cases and be safe.
Link to crappy video, if it works at all
I read a few threads about annealing and over annealing in last few weeks. A few posts got me thinking if it is possible to over-anneal a case head and if yes then how long does it take.
Just so we are on same page : different cases, different manufactures and even different lots will act differently so take this info with grain of salt.
I didn't wanna use a socket coz that would act as a heat sink plus I wouldn't be able to see when tempilaq melted. Also I wanted to create worst case scenario. I used 650 deg tempilaq coz I believe (just me, some people say 600)that's where brass starts to anneal. So I put case in Lee case holder and spun it with drill in the propane torch flame set to max with center blue flame just touching the case at neck shoulder junction.
First I did it with Lapua 308 case, I videoed it too. I'll try to upload but no promises as I have never uploaded video before so it may not work.
The picture is setup with tempilaq along the side & just above the case head (around the case)starting at 0.350" and finishing at 0.500" from case head(roughly). This is where I believed it's still supported by chamber but close enough to the head where if annealed I wouldn't fire that case again. I'm gonna call it "tempilaq belt"
Result: At full blast of "my" torch it took about 7 secs to melt tempilaq inside the neck(usually I'm done here) about 16 secs where case neck started glowing and 38 secs when I first noticed top of tempilaq belt staring to melt. I took 58 total secs where complete tempilaq belt was done.
I repeated the test with Winchester case, times were only couple seconds less compared to lapua.
Verdict: You guys come up with that. IMHO, this was worst case scenario where there was no socket acting as heat sink So unless you keep heating the case for another 15 seconds or so after case neck starts glowing(case is already not useable for precision work at that point) it is hard to dangerously anneal a case. Please don't quote me on that coz someone is gonna come along and prove me wrong.
Once again don't reuse such case, short cases will overheat faster and if you blow up your gun don't blame me, blame Mr Obama for that.
There you have it, don't over anneal cases and be safe.
Link to crappy video, if it works at all