Yesterday I received my mould for my new Bob's Boattail Airgun Bullets from NOE.... It is a 2-cavity aluminum mould with a Lyman style HollowPoint pin in one cavity.... I am absolutely delighted with the quality of the mould, and the bullets it produces.... First, some pics of the mould....






I conditioned it according to the enclosed instructions, used a film of Sprue lube, preheated it to about 400*F, and with my lead at just over 720*F I started casting.... I was using pure lead with about a 1.5% tin content (I had mixed roughly equal parts of 1% and 2% that I had lying around).... I discarded the first 10 bullets, and once the quality settled down I cast about 20 more.... The HPs were not filling out well, with a few wrinkles and rounded edges on the base, but the FN bullets were good for the most part, just a few with rounded corners on the base.... I dropped those bullets back into the pot, and increased the temperature to just over 760*F, and the FN bullets were then perfect, but about half of the HP still had rounded corners on the base.... You could observe this after cutting the sprue and before you opened the mould, as a slight line between the bullet and mould.... By this time I had found a tempo and method that was working well, but I still needed more heat.... I gradually increased the temperature until every bullet showed a completely filled base with a square corner, and found that required just over 800*F for the HP bullets.... The FN bullets were still casting perfectly, so that is what I found works for me.... The temperature was measured with an Infrared Digital thermometer, my dial thermometer, which I know to be out by 100*F, said just over 900*F.... I did find that overfilling the sprue on the HP moulds was necessary to get perfect corners every time.... I ended up with a sprue puddle nearly dime-sized on the HP side, but just larger than the sprue countersink on the FN worked fine....

When I sorted and examined the bullets, I ended up discarding about 30 of HP bullets, presumably the ones first cast where the temperature was not high enough.... I ended up with 115 FN and about 90 HP bullets that are virtually perfect in every way.... I then weighed and measured them and got the following results....

The FN bullets weighed an average of 50.8 gr., varying over 20 bullets from 50.6 to 51.1 gr.... The nose diameter was 0.2515", the midbody was 0.2415", and the driving band was 0.2535", with all bullets being within 0.0005" of those dimensions.... This places them 0.0015" over the design size, just about perfect to allow for sizing, IMO....

The HP bullets weighed an average of 47.8 gr., varying over 20 bullets from 47.7 to 48.1 gr.... The diameters averaged 0.0002" less than the FN bullets, so still 0.0012" over design.... I am delighted with these results.... Here is a photo of the bullets....



I am very pleased with the results of this casting session.... and look forward to seeing how they fit the magazines and barrels, and whether they need sizing.... and of course how they shoot....

Bob