Project - Machine Turned Solids

[Dimitri]

As it is the mass production economics are already intimidating and questionably as to whether folks would be willing to buck up in that magnitude.

Well it wouldn't be too expensive to make them even in a mass production sense. Atleast in my mind. Let me get back to you on this with a drawing or 2.

Still if you can make a bullet that will give decent performance not only on game but target wise. I will buy into it even if its the cost of Sierra's Match Kings.

Dimitri

 

[Brobee]

BigUgly: Did not do a real BHN test, but did do some poorboy testing which consisted of making a steel baseplate with .310 hole to hold bullet, encapsulating with pipe (sleeve), dropping heavy steel rod from known height down sleeve onto bullet tip, observing and comparing deformation between annealed and non-annealed). All this served to do was to give sufficient confidence to mix up the gelatin required to do the terminal ballistic test detailed above. Results from that test indicate definate difference between the poorboy-annealed vs the non-annealed, giving me enough confidence to spend real money doing a proper annealing test. The next batch will have a bunch of post-annealing materials testing done on them as well as some microscopic comparision/analysis. Same tests will be performed on a non-annealed control group to allow meaningful comparison. Tests will be performed by material specialists using real science gear, not my poorboy-bubba-land-garage.

Bottom line, while the poorboy tests were admittedly very crude they were a great in that they very cheaply demonstrated that annealing was something worth investigating more thoroughly.

 

[Brobee]

Not sure what happened last night, but above two posts needed some serious fixing.

 

[Brobee]

update:

Finally got the next set of bullets spun up and sent off for annealing...woohoo!

First up was a professionally annealed revised hollow point with a delrin tip (first batch were made from nylon). Reports from the machine shop were that the delrin was much easier to machine and then sort tips from chips....tips also fit much tighter into the hollow point cavity. Hollow point was finished with a little ball mill, drilled 0.130" deeper than the previous batch, and hex broached to the same depth as the last batch. Bullets were then sent out to a heat treating shop and carefully annealed. Performed BH tests afterwards and confirmed significant softening of material.

After receiving them and checking for tolerance acceptance I made up a big batch of gelatin and a week later headed out to the range once all the blocks had set and stabilized. Bullets were fired from my 18.5 inch barrelled Remington 700 scout and chronographed at ~2675fps. I budgeted 4 blocks for testing this design and was very surprised by the results as they all fragmented to a much greater extent than those in the previous test runs. Gelatin blocks pretty much all looked like this:

One bullet held together long enough to penetrate a little into the second block, but the other two rounds fired fragmented not only as their petals tore off but also down their longitudinal axis and wound up deflecting all over the place within the first block. I only recovered one partial fragment of the bullet shank - all of the other large shank fragments deflected enough to exit out the sides of the gelatin block and were lost in the range somewhere (I looked everywhere to no avail! Cr*ppy!). I have not had the time to set up the camera for macro photography to show you the recovered fragments but will do so when time allows. As it stands the first iteration of the self-annealed and non-annealed bullets are, IMHO, significantly superior.

The other test candidate was something a little different, inspired by the dangerous game bullets used by some african hunters. When trying to settle on the geometry I wound up monkeying around quite a bit with my hobby lathe to come up with a metplate/ogive geometry that would still reliably feed in my M1A but remain true to the flat metplate design of the dangerous game style bullets. The result was a bullet with a 0.26 diameter flat metplate that then flares out in a straight tapered wedge ogive (straight line, no eliptical shape at all) to .308 finished diameter. These were also professionally annealed. Gelatin testing of this bullet also surprised me quite a bit in that it completely penetrated two blocks of gelatin and then had enough energy to travel 40 yards downrange and audibly strike the steel deflection plate in the range's bullet trap. I was choked to not recover the slug as I wanted to see to what degree the metplate mushroomed out. I was also quite surprised that a bullet with such a large flat metplate would penetrate that deeply. Also interesting was the geometry of the hole in that it was clearly crushed/cut for at least 30 inches. Based on this one test I'm thinking that if I ever had to hammer at close range something big that might have 12 to 18 inches of muscle and bone inbetween the skin and the vitals this would be the bullet I want. Finally...more fuel for the next bear defence thread!

I'm currently whipping up some more gelatin for another test next week where I'll use three (maybe even four) blocks to make sure I can recover the projectile. I'll also try to get out to the range for some long range chrono work to try and get a feel for trajectory and how crappy this puppy's BC may or may not be. Afterwards I'll also try to carve out some time for macro photography so I can post pics of the unfired and fired projectiles.

Next iteration from the machine shop will be ball nosed hollow points cut to exactly the same depth as the first batch as well as a second batch where the hollow point is 0.100 more shallow....will be trying to manipulate only one variable this time to understand effect of cavity depth on fragmentation.

Cheers,

Brobee

 

[ATOM]

Very cool. Congratulations!

As has been noted, we can expect a large ecobase market in the near future. Army ranges are now regularly cleaned out of lead. The numerous rural ranges are going to be officially noticed sooner or later when the counties and RMs decide that lead leaching into the water table is Bad.

The French has a long history of solid copper alloy rounds, two being the modern the THV Archane mentioned earlier and the 8mm Lebel Balle D, a solid brass (not bronze) bullet. Billions turned on lathes.

Canadian innovation at its best! Let us know when you decide to sell stock...

 

[trevj]

Nice!

Coupla things, though.

BigUglyMan, you gotta do some reading on heat treating of copper alloys. If you tried what you suggest, you would end up with a corroded mess, and nothing softer than it would be if you brought it to heat and quenched it immediately. In actuality, copper alloys generally harden by being cold worked (usually by the machinery rolling the barstock or sheet out to size), heating softens the material, the quenching cooling rate simply limits the time that the alloy is exposed to oxygen and corrodes faster (from the exposure to oxygen while hot). If you wish to slow cool copper alloys, you really need to look at inert atmosphere furnaces ($$$) But there is no gain to that.

That all goes out the window if you are dealing with an alloy that precipitation hardens, too.

This is why annealing cases is done, and why it is done the way it is, usually. Reloading and firing are working the brass back and forth, heating softens it, plonking it into the water prevents it from corroding worse than it has to (as well as limiting the travel of heat down the case, if you use the 'standing in a tray of water' routine).

Atom, what was the alloy percentages of the Balle D to make you call it brass rather than bronze? Classically, copper/tin gets referred to as bronze while copper/zinc gets called brass, but there is so much overlap, and stuff that fits neither category, that calling the stuff one thing or the other is pretty much meaningless without an alloy designation.

Cheers
Trev

 

[kombayotch]

fyi, here is a solid that is designed to expand at subsonic velocities from 300 Whisper:

 

[Suputin]

Where did you get that? Or more importantly where do I get them?

 

[joe-nwt]

Very cool. Congratulations!

Army ranges are now regularly cleaned out of lead. ..

You don't suppose there's a chance this is due to the price of lead the last few years.....

 

[kombayotch]

It isn't mine... belongs to someone I was sharing ideas with.

I am working on a subsonic bullet, but it isn't turned. It's a segmented HP lead bullet that's plated in copper. Basically, a .30 cal version of the new CCI segmented subsonic HP round.

 

[Lazerus2000]

Cool ....
solid bullets made in Canada ...
TRES COOL!!
Brodee,
keep up the great development work,
and thanks for sharing,
LAZ 1
[;{)

PS: just as a historical reference, I don't suppose many of you are old enough to remember the old, old ORIGINAL Canadian plastic tipped bullets from Imperial aka the Saber Tips??
I think these may have been invented in canada, and it is noce to see the circle coming around.

 

[Splatter]

I do !
I also remember a CIL design with a hollow cavity behind a closed jacket nose. I forget what they were called.

 

[Why not?]

They were called "Pneumatic bullet". All the ones I saw were loaded in the 30-30, and they were quite an effective bullet on deer.

Ted

 

[Brobee]

In an effort to try and recover one of the "dangerous game" spirited solids my brother and I loaded up the car and went down to the range this afternoon. With temperatures forecast to be really warm the next couple weeks I was moderately stressed out to get the tests done such that the gelatin would be at the mandated 4 degrees C...I only have my insulated detached garage as my "refrigeration system" and while I have the ability to heat, I don't have the ability to cool! This morning the thermometer read 4 degrees so we packed up and off we went.

Many many many thanks to the local IDPA boys who had commandeered the range to shoot an organized match. When my brother and I showed up with our gelatin blocks they were not only kind enough to let us squeeze in to set up our test apparatus but also helped us pack all the steel plates and gelatin back out to the car once we were done firing our single round after a good BS session around the then-shot jello.

The test apparatus consisted of three rifle sized ballistic gelatin blocks on an armoured steel plate and rigged up a wooden backstop with a steel backup just in case. This time we were lucky enough to recover the bullet, after an impressive 50 inches of total penetration:

As discussed previously, the bullet has a massive flat front metplate with a conical ogive. They were machine turned from a lead free solid copper alloy. They were then annealed by a professional heat treating shop. The annealing process did not use an oxygen free atmosphere, so there was considerable oxidation on the surface finish of the projectiles so we had some of them roto-deburred so they would not look quite so ugly. The photographs below compare an unfired roto-deburred projectile with the recovered slug (which was not roto-deburred, thus the discolouration of the base).

The handload used to produce the test round was downgraded somewhat....my thinking here was to try and emulate the type of velocity the round would see somewhere between 100 and 200 yards and seeing how this thing is not very aerodynamic it likely bleeds velocity quite quickly. Also contributing to my "downgrade philosophy" was a desire to recover the projectile. In an effort to be polite to the guys letting us hone in on their range time I left the chronograph in the car, however I have 12 identical rounds I loaded up at the same time which I'll use for detailed velocity studies next time I hit my outdoor range for some fun. My target velocity was somewhere in the 2200fps to 2300 range.

Also on the agenda when I hit the outdoor range is to do some downrange velocity studies with projectiles pushed up around standard 155gr .308 velocities. After doping out the various trajectory related come-ups I'll set up the chronograph downrange and get some velocity readings in 50 yard increments from the muzzle out to 300 yards or so. This should be enough for the ballistics experts (not me!) to make some calculations on ballistic coefficient as well as give us general guys an idea of the maximum effective point blank range you might enjoy in your "dangerous game" rifle.

Observations are that the projectile does indeed expand, temporary stretch cavity was well developed in the first block (continuing several inches into the second block), and surprisingly deep penetration given it's very non-aerodynamic shape. Also interesting are the crushing/cutting properties of the projectile. Unlike typical shaped bullets with a pointier elliptical ogive, the flat metplate of these projectiles cut/crush immediately and create a hole in the gelatin that you can literally poke a pencil into and not have it touch any gelatin. There is no stretching to get out of the way...tissue is simply cut/crushed.

Will post more as I experiment and learn more, but will likely not be for a month or two as time is tight this next little bit!

Cheers,

Brobee

 

[Splatter]

Hmmm, looks like your bullet could use a bit more diameter.

 

[burnt_servo]

sweet thread ........

going back to the first post , and the concerns about lead dust , what if you made a pointed bullet mold and cast bullets using a hard silver based alloy ?