Originally Posted by
SAndy37
Ok, now here's a connundrum....
I'm a commercial ammunition manufacturer. (I'm also a serial lurker in this thread) Typically we load either J-word of electroplated CMJ bullets that we source from a manufacturer locally. We have bought in a reasonable quantity of Joe's Hi Tek powder some time ago to coat some of our own castings in more obscure calibers that dont require high volumes, and went through the whole learning curve. We coat using foundry lead (92-8), commercial acetone, and a commercial convection oven.
(Please bear with the long post, I'm trying to give enough detail to limit questions later)
Our initial attempts worked OK- for personal use- but the resultant product, although passing all the tests perfectly, smoked a bit more than CMJs and left a chemical smell in the air after firing. I stopped fiddling with it and carried on shipping in the plated bullets. Late last year, I followed the adventures of Petander here and his acid wash and decided to revisit Hi Tek.
Cast bullets were soaked overnight in undiluted swimming pool HC acid, and boy did they react- foul smoke coming out of a boiling bucket! The resulting bullets were a dark powdery grey that needed scrubbing to remove the powdery residue on them. I then got one of my staff members, who had previously been doing the shaking and baking to coat and bake them for me and we loaded up a batch (testing smash and wipe 100%) that were coated 2x (124gr 9mmP) and took them to test. these bullets were perfect, they shot accurately, the recoil felt softer than normal, but velocities were about 50fps faster than the plated bullets with the same loads, and there was no undue smoking. Best of all, the chemical smell had dissipated. There was no leading at all either. The reason for using 124 gr 9mmP was to test a higher pressure bullet than a 38 or a 45.
Ok, so whats the problem you may ask?
We have been casting and loading coated bullets for the last two months with no issues. The local market has been slow to adopt them over the more traditional CMJs as range ammo, but we have now developed a nice following. Last week I checked on the process my staff are following, and found that the idiot here has been baking the two coats at 110 degrees centigrade for 10 minutes instead of at 200 C. He has done two months of production like that. Everything I have read here says that there is no way that the coating would have worked like that, but- and I took 1000 rounds of 124gr 9mmP to the range this weekend and shot them through 3 different 9mmP firearms, including a MP5 with a new, tight and longer barrel- I had the same good results as earlier. All these 'poorly' coated bullets more than exceed the two tests, and its near impossible to get the coating to come off, even when hammered thin multiple times. There was no leading in any of the firearms, accuracy was superb, the smell and smoke issues are still solved... colour me stupid, but everything written here by smarter people than me tells me that this should not be the case?
I'm not a chemist by any means, but the acid wash step has really worked for us- the foundry lead we get here is all recycled lead, and still has traces of other unwanted elements in it- the acid sorts that out and leaves a pockmarked surface that implies a great coating surface.( Thanks Petander, for the clue to solving the problem!) It may be that traces of the acid have helped the adhesion (??) and made up for the mistakes of my staff member- I dont know. Its a mystery to me. Future bakes will be done as per the instructions, but- and I dont know why- what should have been a horrible failure has tested to work as if it had been done in accordance to the instructions. the only additional step we have put in the process is the acid wash (Which, unlike Petander's wash, uses undiluted acid for 18 hours) In addition, about a hundred thousand of these 'mistakes' have been shot by satisfied customers this year already, with no complaints and nothing but compliments.
Amazing stuff, this Hi Tek!