1Shirt
07-30-2013, 02:00 PM
I am a firm believer that the hollow point version of a boolit is potentially and inherently more accurate when properly cast than is the non HP version of that boolit. I have for a number of years weighed all of my HP's of all cals and weights for rifle boolits, from 22's thru 45's. The little ones 22's & 6MM's, I segregate on a small digital scale to exact weights, and store them accordingly load per exact weights. For 6.5' thru 7MM', I segregate to within .2 grain, and for 30s to within .3 gr. For my .375's for hunting within .3gr, but for target I want exact weights. For 44's .3 gr. is fine, and for big heavy 45 cals to .5 gr for plinking/target work, and to .3 for hunting. I have always preferred to use a bottom pour 20 lb pot, rather than hand dipping, and have have a 20 lb pot or two for well over 40 years. Now to the issue, of pressure casting from a bottom pour pot:
Over the years I have just used a non pressure method of casting, and carefully inspected boolits prior to sizing and lubing, discarding and remelting the culls. However, with HP's visual inspection is far more of an issue, due to the nature of the casting process. As a result, and over the years, I have learned that pressure casting with a rhythm for consistency produces far closer weight tolerances for HP's than non pressure methods. My method of pressure casting HP's is to insure the cavity is full, then drop the mold a bit to allow a small sprew to form. I have found that this produces the most consistant weight of boolit. Using this method, on smaller boolits, I seldom have a variance exceeding .5gr, and often on batches of 100 or so, .3 gr. is not uncommon. Little 22s in my experience require exact weights for consistant accuracy, and due to the small amount of lead going into the mold requires that you develop a technique just for them. I also recommend that you stir the melt frequently to maintain consistency, at least ever 40-50 boolits.
Anyhow, just thought I would pass this on!
1Shirt![smilie=l:
Over the years I have just used a non pressure method of casting, and carefully inspected boolits prior to sizing and lubing, discarding and remelting the culls. However, with HP's visual inspection is far more of an issue, due to the nature of the casting process. As a result, and over the years, I have learned that pressure casting with a rhythm for consistency produces far closer weight tolerances for HP's than non pressure methods. My method of pressure casting HP's is to insure the cavity is full, then drop the mold a bit to allow a small sprew to form. I have found that this produces the most consistant weight of boolit. Using this method, on smaller boolits, I seldom have a variance exceeding .5gr, and often on batches of 100 or so, .3 gr. is not uncommon. Little 22s in my experience require exact weights for consistant accuracy, and due to the small amount of lead going into the mold requires that you develop a technique just for them. I also recommend that you stir the melt frequently to maintain consistency, at least ever 40-50 boolits.
Anyhow, just thought I would pass this on!
1Shirt![smilie=l: