Ammunition & Hand Loading > Cartridge and Shotshell reloading
Powder Coating Lead Bullets
unfy:
Drilled new holes for the hollow pointing jig, works good now. 0.106 - 0.1.07 all the way round now :)
DangerousDrummer:
Ok, I didn't get to the range because I just ran out of time. My pin in the mold base plug was too long which made it hard to drop the bullets out of the mold, so I incrementally shortened it and also added some taper.
I checked pressing into a case and adjusting my SOCOM dies using a case guage(the SOCOM is VERY unforgiving). Then cast enough for a full PC batch. I also used my MagLight to make sure I did not see any shine through the coat. The loaded tray in the oven..
Out of the oven. This shows the semi-boatail bottom with pin hole. The coverage is good.
Ten test rounds loaded. Note the FrogLube, I use it as my bullet lube. Did you know it will not burn? I use it on my molds also. It disappears when cold and reappears when hot if initially properly applied. It ain't grease and ain't oil so you cannot mix it with either. It MUST be applied when the surface is hot so that it can absorb in the molecules of the metal.
Ready for the range. The PC bullets along with the hollow points cut with a center drill. Gonna rain tomorrow, so maybe next week I can test with the chrono.
unfy:
looking sweet, dangerous! i know folks are curious how things behave in rifle, and big bore is a noted exception to what ppl have repoted :P
my drill guide jig thing is a failure. the guide is too close to the bullet nose face, thus the material doesn't really have anywhere to go and... yeah... :(
pushing it back didn't help either.
trying a few case trimmer hollow points (3/8ths or so ?) ... they wibble wobble on the nails which aint cool.
i'm at a loss for the moment on HP jig / nail setup. i *really* don't wanna drill out all those rivits and replace the nails with something bigger-hp friendly (for when eventually getting hp molds maybe).
for now this means the wire lube groove jig.
DangerousDrummer:
--- Quote from: unfy on April 14, 2013, 10:06:07 AM ---looking sweet, dangerous! i know folks are curious how things behave in rifle, and big bore is a noted exception to what ppl have repoted :P
my drill guide jig thing is a failure. the guide is too close to the bullet nose face, thus the material doesn't really have anywhere to go and... yeah... :(
pushing it back didn't help either.
trying a few case trimmer hollow points (3/8ths or so ?) ... they wibble wobble on the nails which aint cool.
i'm at a loss for the moment on HP jig / nail setup. i *really* don't wanna drill out all those rivits and replace the nails with something bigger-hp friendly (for when eventually getting hp molds maybe).
for now this means the wire lube groove jig.
--- End quote ---
I have a saying.. "perserverance beats brilliance". It has served me well over the years while working R&D in fishing rod design, and especially software design and programming.
There are two main concerns that I have.
1. How well does the coating hold up on the lands? I should probably allow a longer curing time before loading or shooting.
2. Balance? As near as I can tell, the coating is more perfect than the casting imperfections.
So back to perserverance. When struggling with a process design, the first question to ask is what is my final goal?
Shoot inexpensive cast bullets with no leading and no gas checks.
As far as I know there are three ways to achieve this
1. Plating We are still working on this process
2. Powder coating. Our current process R&D
3. Old school sabots. Yes these will work in cartridges also.
Both 1 and 3 have more process steps so they are more complicated, which leads us to powder coating which is relatively simple and inexpensive.
So what are the process steps?
1. Cast and inspect the bullets.
2. Size if needed. I think sizing is not required for larger calibers and sizing risks adding lube to the bullets which should be removed prior to coating.
3. Clean the bullets
4. Coat the bullets. (this is the step that determines the final quality). There is one main objective of coating. Uniformity! We want 100% coverage while covering all sides the same amount. The faster the bullet and spin the more this is critical.
5. Bake the bullets. Ding! Bullets are done.
Step 4 is the critical step, and the one that is the hardest. So the problem is, how to hold the bullets while coating which allows direct transfer to the oven with the least disturbance?
Obviously a tray that fits into the oven is required. Easy decision
Now how to hold the bullets? Bullets with lube grooves seem the obvious choice. But remember, we want uniformity for balance, so can we really use the grooves and expect coating uniformity? I do not think so. The only way to achieve balance is to hold the bullets from the center because any place that the holding jig is touching the bullet will not get coated. So if you want balanced bullets, I think the lube grooves are out. So hold the bullets by the center.. There are only two ways to achieve this.
1. Some sort of clamp with pins.
2. A single pin which will require some sort of centered hole.
Which is simpler (kiss is always best for processes)? A single pin.
1. Mount pins to the tray. Relatively easy. BTW I like your method better as there is less warping.
Now mount the bullets on the pin.
2. Mount the bullets on the pins. A centered hole is required for balance. Hollow point bullets are perfect if you have a hollow point mold. Unfortunately, neither of my molds are HP, so I have to come up with a way to put centered hole in a bullet. Luckily I have a lathe, because without one you may be able to put a hole in either the base or point of a bullet but it likely will not be centered. For the muzzleloader I chucked each bullet and drilled. Hole is centered and with drilling soft lead there is no dust but the bit does tend to grab, but this is very time consuming. For my 458 mold, it had a core plug which I was able to replace with a plug that has a pin. In your case, without a lathe, you are pretty much restricted to HPs.
So you have HPs but the pins are too small for the HP holes. Two options..
1. Replace the pins. Lose all the fine work you have done installing them? I don't think so!
2. Find something to use as a bushing. Sounds a lot easier to me.
So a bushing..
A. OD matches ID of one part, bullet end
B. ID matches OD of the other. Pin end
Your nails are pointed so B is not a critical demension but a bushing that will fit closely to the largest diameter of the nail will prevent wobble on B, and an OD that closely matches the bullet Id is best.
What comes to mind first is a pellet from a pellet gun. It is lead so resizing may be possible, and it has a hole which could be used as a center hole for drilling if required. Another thing is a spent shotshell primer. Maybe some brass beads used to make necklaces.. Brass tubing from Hobby Lobby.
I think tubing will be best. OD of B, ID of A.
1. Shorten your nails so it does not take as much.
2. Purchase OD to match ID of HP.
3. Wrap nail with wire to match tubing ID.
Solution! Hope this helps. My bullets are perfect and I am sure will shoot well as both calibers are shot at fairly slow speeds. All that remains to be seen is how much they prevent leading. I am not worried about vaporized lead as even paper patching prevents vaporization, so all that remains is lead on the lands. Will know for sure next weekend. I still intend to persue plating now that I have a good power supply.
unfy:
Well, i did a round of wire jig with lube grooves. Went fine.
Then decided to just go with the holes-drilled-in-cookie-sheet jig. Seeing as how it did just fine at the range last time... and allows 3x as many bullets coated at once.
I've noted I have a fair amount of powder on my lazy susan and 'paint hood'. Will fetch a small brush and attempt to recover it. It's been out in the moister, so I imagine after recovery it'll need some very violent shaking for an extended period so that it's broken back up etc. I'll keep it separate from regular powder so can see how it affects things.
Now, as for DD's awesome breakdown on suggestions....
I too was thinking along similar lines. Powder coat is definitely easiest and seems to work wonderfully on the single bullet type I've bee able to test it with. I've been pondering plating some more, but trying to avoid getting too involved in it... too many complicated things at once is bound to mean a mess up... and already wanna get my air compressor box built. It's funny, my box is gonna end up costing more than the compressor ... sigh ...
I will note, for pistol rounds, I don't think the lube groove weight imbalance is such a concern. On rifle from 100-300 yards, it undoutedly is.
The original design of the rig that became lube-groove-wire jig... I think is a plausible concept. This would be two needles/nails pinching the bullet on from base & nose. Maybe not in the vertical form that it was done in... it prolly needs to be horizontal... and then there's the obvious trade off of losing bullet density per tray. For human simplicity, it would prolly also need to be a spring loaded design. The wire-groove stuff has been through the curing process twice, i'll try spinning bolts to see if they move at all, i'm willing to bet they don't :).
But, the hollow pointing approach really does seem to be the ideal way to go.
My HP jig appears to be a bust.
A) For some reason there's a fair bit of play in the guide hole now.
B) The lack of being able to eject removed material is a huge problem
C) The bullet will still spin in the cavity, even with a decent amount of force applied downward on the jig.
D) You *can* use some vice grips (set to not be very tight) to hold on to the bullet base without deforming it
E) Lead is harder to drill than I thought.... the amount of force required really does hint at wanting to use a drill press to avoid snapping bits and getting better holes
F) If using a drill press, there'd have to be something done to grip bullet bases. Bolts pushing on a ==( shaped thing come to mind.
G) All of the hollow pointing drill guide jig stuff really wants to be made out of metal rather than wood, thus it's beyond me (darn lack of tooling).
-----------
So. Hollow point molds. Bought reconditioned lee/lyman/rcbs molds or from-factory-with-hollow-points will all have large HP cavities for their terminal characteristics.
Yes, the nails are too small for typical hollow point cavities.
So you're right
A) tear apart jig
B) bushings
C) tubing ideas
Tearing apart the jig is a valid solution, and possibly the 'most proper'. Having proper spindles is just 'correct'. Buutttt.... it doesn't allow for much in the way of modularity / re-use.
Bushings are an easy work around and do offer some modularity. While more permanent ideas include DD's most interesting pellet idea... to wirewrap .. to... etc... Aluminum foil might quite possibly make for a just fine temporary one ;).
And now for the idea that I really like, and prolly wouldn't have come up with on my own, the brass tubing.
6D nails are 1-7/8ths of an inch in length. I like that height - makes getting the lower portion (nose in this case) easier. That said, a point doesn't exactly lend itself to very much given that I have to toss my current HP jig idea. A pair of bolt cutters to snip off some ends might be in order.
But the thought of being able to take different brass tubings that have been designed to fit different HP cavities is down right awesome. There's extra work in having to tool up all of the tubes for each style... but... one jig and a box of sheath tubes is so much better than a half dozen jigs.
I'll have to measure the 6D nails again to figure out what their diameter is... if it's a really weird size that doesn't have a matching tube size.... euhhh... we'll deal with that later (tearing apart jig anyway, or even something as simple as good ole aluminum foil again heh... or a wire just to fill up space, etc).
So... for sizing up.... I imagine a center punch or cold punch could get minor sizing done easy enough.
I dunno how ductile brass is. Could the tip get a cross cut put in it, then the 4 sections folded back over itself (much like how a HP 'flowers' on impact) ? This way you could adjust size and possible conicalness via the 'petals'. Maybe it'd have to be annealed first ?
Lets go an opposite direction for just a second.
Take one of your cast HP bullets.
Make a plaster of paris mold of it's cavities (doing proper negatives first, edit: or by removing the hp pins if easy enough).
You should now have a tiny lil thimble sized mold that when filled should match the cavity of your hollow point.
Drill some holes / cut some slits in the end of some brass tubing.
Drop some lead into 'thimble' plaster of paris mold, stuff slitted/holey end of brass tubing in mold, let freeze. Wallah, a lead ball semi-perm attached to end of brass tubing that perfectly matches your hp cavity.
Sizing down shouldn't be a problem. Some of the tiny high speed rifle bullets might require fixing a thumb tack to the end of the tube hehehe (can prolly solder it on).
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