I'm running a 20# Lyman bottom pour, casting straight WW + as little tin as is possible for fill out. 700 degrees seem to suit my brass and iron molds well, but Lee's aluminum is 20 degrees cooler. I use my casting rate to keep mold temperature so that the puddle of sprue hardens in 3-5 seconds, then open just after the 'color' change. I use the time waiting for this to happen by dropping the previous sprue cutoff back into the pot. I flux with straight sawdust, using a piece of pine cutoff to vigorously stir the pot, every 50 boolits. I also very rarely skim off the dross, and keep a 1/4" - 3/8" thick layer of sawdust charcoal on the surface which I believe helps minimize tin oxidation. As a result, I use very little tin whatsoever, and get good fill-out with more or less straight WW's.
Rod
Last edited by Rodfac; 02-20-2015 at 09:06 AM.
So I got my thermometer yesterday and fired up the pot at the usual setting that I have been using. I was surprised to see my setting of 775 on my lyman pot yielded a 600 degree reading on the thermometer. Which every time I add lead it drops about 20 degrees for a couple minutes. From what I am reading on here looks like I need to bump my temp a little. My easiest mold to fill and get decent frosty bullets with COWW is a lee 230GR TC/TL in 45, a little more temp may help fill some of the other molds I have more consistently.
"Yes or no will almost always suffice as the answer"
Quote: I was surprised to see my setting of 775 on my lyman pot yielded a 600 degree reading on the thermometer. Which every time I add lead it drops about 20 degrees for a couple minutes. From what I am reading on here looks like I need to bump my temp a little.
Or better yet, find some one with a PID controlled pot and compare the reading of your thermometer and the PID. If not that, melt "pure" lead and as it just starts go become solid it should be about 621 F. Then note the difference in readings.
Since you were casting at your setting 775, which the thermometer showed as 600 degrees, I suspect the thermometer is off or the lead would not flow.
I was thinking of the doing the pure lead melt to check the temp...don't know anyone that has a PID so that isn't an option
Thanks for the help
"Yes or no will almost always suffice as the answer"
... Different calibers with iron and aluminum molds - Cast between 710 to 730. If high lead content - cast at 680. The key is a 5 second pour and a 5 second sprue puddle frost = filled out bullets than are not frosted
Regards
John
BP | Bronze Point | IMR | Improved Military Rifle | PTD | Pointed |
BR | Bench Rest | M | Magnum | RN | Round Nose |
BT | Boat Tail | PL | Power-Lokt | SP | Soft Point |
C | Compressed Charge | PR | Primer | SPCL | Soft Point "Core-Lokt" |
HP | Hollow Point | PSPCL | Pointed Soft Point "Core Lokt" | C.O.L. | Cartridge Overall Length |
PSP | Pointed Soft Point | Spz | Spitzer Point | SBT | Spitzer Boat Tail |
LRN | Lead Round Nose | LWC | Lead Wad Cutter | LSWC | Lead Semi Wad Cutter |
GC | Gas Check |