Thanks for all the compliments. These things are probably way more trouble than they will ever be worth, but I enjoy the process. As far as making these things there are a lot of things going on. I am running an old Daewoo Puma 4 CNC turning center with an 8 tool turret. Making a bullet uses up 5 tools.
1) Rough/finish
2) Center drill
3) Drill
4) Square punch the hole
5) Cutoff
I will see if I can take some pictures when I run some more. I wan't to shoot these for accuracy, and velocity from my Savage Model 10 (22" sporter) to see where I am at first.
The tip is machined in one pass from Delrin rod.
You can machine simple bullets on a hobby lathe, but complex curves require CNC control, unless you make a form tool for the ogive.
If you know someone with a wire EDM and can provide him with a 2-D CAD file he can easily cut one for you out of an existing carbide tool bit, or even HSS should work for low production levels. Having a custom form tool make would probably cost a couple hundred bucks, and may not be worth it depending on what you are trying to do.
Pistol bullets are actually a lot easier to make on a manual lathe because their ogive radii are usually much smaller. You can also turn bronze solids for big bore rifles the same way. The most common COTS radius bits come in 1/32 increments up to 1/2" so you can give that a try. The other option is making the ogive conical. That may work reasonably well for some bullet designs. Above all make sure you are in tolerance on the diameter (too big a bullet will raise pressure) I try to hold +/- .0002.
bernieb90, thanks for posting the pictures and information. These are works of art!
Joe Mamma
"Reliability above all else"
NRA Certified Pistol and Rifle Instructor, Life Member
Glock Certified Armorer
Beretta & Sig Sauer Certified Pistol Armorer
Colt Certified 1911 & AR-15/M16/M4 Law Enforcement Armorer
I finally got to shoot these bullets this past weekend.
Test media: Water (in 2.5, and 1 gal jugs)
Test firearm: Savage 10 .308 Win.
Unfired, 2945 fps, 2190 fps
Bullet was sprayed with HBN (Hexaxonal Boron Nitride) in order to reduce pressure, and reduce copper fouling. Fouling appeared to be minimal.
I also tested the older hollowpoint design as well.
MV 2832 fps
Overall I would say it went well. I had some accuracy issues, but I may have some damage on the crown of the gun, and I still need to do a but of dialing in as far as the bullet jump goes (right now it is too much @ .065").
why all the cannula grooves...aren't you afraid this is going to disrupt the air flow and decreses accuracy...or being such a lightweight bullet is it strictly intended for short range only?
"Get yourself a Glock, Lose that Nickle plated sissy pistol." Sam Gerard (Tommy Lee Jones)
Ignorance is Defensible, Stupidity is Not!
Someone please correct me if I am wrong, but I believe the grooves serve to reduce copper fouling. I believe Barnes did the research for this and that's why all of their bullets have similar grooves. To sustain a solid copper bullet in the market, you've got to reduce the fouling or your bullet won't sell.
Hang up and drive.
Luke 22:35-38
The grooves, or more correctly driving bands serve 2 purposes. The first is a reduction of contact area with the bore resulting in reduced copper fouling. The second more iportant function is to reduce pressure. Since solid copper is not as compressible as a traditional jacketed lead bullet there is typically a greater ammount of force required to engrave the bullet into the rifling. This results in a large pressure spike as the bullet enters the rifling. By cutting grooves into the bullet the pressure spike is greatly reduced allowing larger powder charges, and higher velocities than is typical of solid copper, or even lead core bullets.
My designs are not entirely original, but are a combination of a variety of bullets currently on the market. My biggest inspiration is Gerald Schultz of GS Custom bullets in South Africa. Barnes bullets has also been a great resource.
http://www.gsgroup.co.za/02hv.html
Last edited by bernieb90; 05-20-09 at 10:25.
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