Project - Machine Turned Solids

Nice! They are about as soft as they are gonna get now!

About at this point, y'all gotta hit the measuring equipment and see if there was any dimensional changes to the bullets that can be found. I suspect they are just fine, and that you would see worse damage change, anyways) done by tumbling them or otherwise bulk finishing them.

Question... Do you have the ability to hardness test these? I've seen Ames Portable Hardness Testers (used ones) selling in the $350 range. They are pretty much an industry standard tool, and easy to resell. Knowing the exact hardness would allow you to both test varying hardnesses for effects, as well as verify that you are getting the same results each batch. Just a thought.
Knowing someone local to you with a hardness tester is as good.

Yeah yeah. More stuff to spend money on....:D It never really ends!

Cheers
Trev
 
Have you considered marketing the hunting bullets without tips? Srsly, at normal hunting ranges, how much drop/drift difference will there be? Maybe 4" at 500m?

And as regards the "lead free" idea and your reluctance to use free-machining material with 5% lead.... You do realize that much of the soil in Canada has naturally occurring lead, right?
I'm not saying you're wrong to pursue you cool ideas, just that the dust you are kicking-up probably has lead in it already.
 
trevj - Before I do any hardness variable harness experimentation or measurements ofr hardnessI'm going to go out and do a quick and dirty gelatin test to see if there is any change in shearing/expansion performance. I did some poorboy testing out in the garage and it does seem like bullets given the torch treatment are much easier to deform either via dropping or mutilation by pliers, so i suspect you're right that they have softened up considerably. After doing all my amateur research on the internet, I was a little worried about oxygen embrittlement but without the hardness tester and a dedicated oven with purge gas this will be a little hard to test. I did try torching a few in a CO2 rich environment (was a bit of a challenge to get oxygen to the torch when blowing CO2 from my bulk airgun refilling cylinder across the bullet, but I managed to poorboy something relatively effective) and could discern no difference in the degree of softening effected to each different batch.

Given feedback in the companion thread over in the hunting forums though it's looking like folks would prefer a bullet where the petals fragment rather than peel so it all might be a moot point anyway.

Splatter - re lead free - I do alot of shooting; in the neibourhood of several thousand rounds of centerfire a year and when I do the math on how much lead that is shooting conventional bullets on my newly built rifle range out on our vacation property it would not be long before I'm well above the Canadian Soil Quality Guidelines for the Protection of Environmental and Human Health (70mg/kg or 70ppm for agricultural land). Given that I have two small children who play out there lots and the fact that we also want to use the land for cattle/buffalo it seems like the responsible thing to do is make a resonable effort to go lead free. And if I'm going to market a bullet as lead free, then it should probably be lead free...:)

Re offering a slightly more economical version without the polymer tip - sure why not. But I think there are those who will, for whatever reason, believe the tip offers superior performance and would be prepared to pay for it (or rather choose not to buy it because it does not have a tip) so I'm going to put some work into understanding them a bit better. Also, because the bullets are less dense than their leaded cousins, they are already at a ballistic disadvantage and I'd want to do everything I could to close the performance gap.

nvyshtr - 9mm - machine turned lead free 9mm would be cost prohibitive (already looked at it), but I do have tooling on order to swage conventional FMJ filled with a compressed copper/tin powdered metal mixture, the base of the jacket then being rolled back for good gas seal/stability. These should be much more cost effective, likely on par with what is currently available in the cast/plated world. I am aware of at least a couple of canadian bullet makers looking at this, so depending on how far behind on the learning curve I am I might leave this to others already doing their homework. If, by the time I'm done with my own personal experimentation, no one else has stepped up to the plate then I'll look into getting tooled up for mass production. As an aside I still have to try and jump through all the hoops to get my range government certified for restricteds....:)

Will hit the range tomorrow with the gelatin and annealed bullets in tow. Should have something to post by late tomorrow evening or early next week sometime.

Cheers,

Brobee
 
Range Report!

Non-annealed bullet gelatin pictures first:

gelatin_non_annealed_a.jpg


*note* - second gelatin block had no temporary stretch cavity and bullet deflected sufficiently that it exited the block. A photograph would have revealed an empty block. Bullet exited block after a total of 32 inches total penetration and was found on the floor downrange approximately 10 6 feet from the table...see below in the notes section for more details.

gelatin_non_annealedl_crosssection_a.jpg


gelatin_non_annealedl_crosssection_b.jpg


gelatin_non_annealedl_crosssection_c.jpg


gelatin_non_annealedl_crosssection_d.jpg


gelatin_non_annealedl_crosssection_e.jpg


non_annealed_recovered_fragments_a.jpg


non_annealed_recovered_fragments_b.jpg



And now for the annealed bullet gelatin results:

gelatin_annealed_a.jpg


gelatin_annealed_b.jpg


gelatin_annealed_c.jpg

same block as in previous photo but as seen from the backside- projectile was much closer to this side and thus shows more clearly.

gelatin_anneal_crosssection_a.jpg


gelatin_anneal_crosssection_b.jpg


gelatin_anneal_crosssection_c.jpg


gelatin_anneal_crosssection_d.jpg


annealed_recovered_fragments_a.jpg


annealed_recovered_fragments_b.jpg




Notes and observations:

- There is definately a difference in projectile petal fragmentation between the non-annealed and annealed bullets!

- Only had time to set up 2 shots before extended family commitments stole me away....:( I tested one annealed bullet and one non-annealed bullet

- I was only able to recover 1 projectile in gelatin (non-annealed), the annealed projectile actually popped out at about the same total penetration depth as where the non-annealed one piled up right against the edge, it had so little residual velocity that I could see it arc through the air, rise about 3 feet above the gelatin block, and then drop gently onto the floor of the range. I feel lucky to have recovered it.

- Both bullets initiate expansion almost immediately (within 1 inch of gelatin penetration)

- Non annealed bullet fragments almost immediately...within the first 4 to 6 inches. As it begins to shed petals it starts to corkscrew through the gelatin. Petals break off in small, sequential longitudinal chunks. Chrystaline structure of copper visible along fracture lines....looks to be quite brittle

- Annealed bullets have their petals break off much later in the wound tract and in much larger pieces. Appearance is that they have much more plastic deformation.

- Petal detachment in the annealed bullets appears to happen at approxiamtely 16 inches. This also appears to happen in a relatively uniform fashion.

- Annealed bullet appears to swage up somewhat to better match diameter of bore.

- Annealed recovered slug-main-body exhibits a much greated degree of nose swelling (expansion).

- Annealed bullet travels through the first block of gelatin with a much more straight (less corkscrew) trajectory than the non-annealed bullet. Towards the end of it's travel though it deflects quite a bit.

- No evidence of either bullet tumbling, although both exhibit deflection towards the end of their travel.

- I still suck at documentation - I only discovered the cool aspect ratio of the cross sections after getting started on fragment recovery for the non-annealed bullets and by then it was too late to take a photograph of the first inch and a half.

- Cross sections are approximately 1 to 1.5 inches in depth each.

- Permanent stretch tearing happens in a symetrical geometry remarkably similar to the orientation of the broach lines/petal expansion planes. I will speculate that having 6 petals rather than 4 is better...in that a larger number of these tears will bleed an animal out faster. Both annealed and non-annealed bullets exhibited the same behavior in this regard.

- Both slugs exhibit similar weight retention around the 80% range

- Both slugs penetrate to approximately the same depth.

Ok, so weigh in folks! If you had to choose one which would it be and why?

I need to do some musing before I'm comfortable with where to take the project next....my initial thoughts are that I still want to try the parobolic cavity (and for sure anneal the bullet with the parabolic cavity), but before deciding on anything I need to figure out where I sit on the fragmentation issue.

Anyway...thats about all I have for now!

Cheers,

Brobee
 
Just off the cuff -- I'd say the non-annealed version, because it breaks into smaller pieces, and because it breaks into pieces at a depth more suitable for deer-sized critters.

I am seriously, very, very interested in this project. A lead-free bullet that does the "shrapnel" thing like the AccuBond's I'm so fond of, is a bullet I would very seriously consider for my hunting uses, assuming cost is even vaguely sane.
 
What distance and velocity are you fireing these into the ballistics gel? To promote pealing and not fragmenting is it possible to score the inside of holopoint cavity along the hex shank to help it peal back?
I know this is a pistol bullet but you can clearly see in the pedal edges a v notch cut into the bullet before it had been expanded... you could also try a smaller holopoint opening to keep the bullet from expanding right at impact.
19886.jpg
 
I dont know what the industry standards are for distance and testing but looking at pics of the new hornady GMX bullet at 2700 FPS it pealed back nearly half the length of the bullet. I dont think it makes much difference if its hitting at 5 meters or 100 meters if both hits are at the same velocity performance should be the same. After looking at several commerical soilds I think your holopoint cavity needs to be a bit deeper to at least the depth of about half way down... on your one test bullet it looks like it started to get the pealing effect.

PS. Great works so far these little bumps will iron themselves out with experimentation
 
I have been watching this thread for a while know. I must say that I really agree with MSG DREW. I believe the hollow point should be deeper, alot deeper. I think that you would get better "peeling" if the hollow point was deeper. I also believe you would see less penetration. Have you thought about slowing them down a little. maybe to 2300 or 2400 to see if the petals shear off at those speeds as well. Are you sure the copper you are using is of the same quality as the larger manufacturers are using.

My thinking is if the petels are shearing at any speed than you probably have the wrong copper mixture or your hollow point wall thickness is to thick.

I am just throwing idea's out there. because you never know

I must say you are fast becoming my personal hero.:dancingbanana:
 
The terminal effect of the non-annealed version looks like similar to a Berger VLD, except that your bullet actually exits and leaves a blood trail (for the odd time that you might need one!)

The annealed version looks like it fragments about like an AB, but again, your bullet seems that it has the explosive framentation effect as well as the crazy penetration that Barnes users rely on so much.

For deer-sized critters I would take the non-annealed version, since the bullet begins fragmenting a few inches after entry. For larger animals, the annealed bullet would be my bullet of choice.

You're definitely on to something, here! :)
 
I am thinking that either one will result in meat, if the shooter does what they should.

Looking at the annealed bullet in comparison to the non-annealed, it's pretty clear that it softened up a fair bit. Just from comparing the way it bumped up in size, as well as the way the petals tore off the unheated one.

Nice work!

Cheers
Trev
 
I would choose neither. That hollow point needs to be much deeper and wider, down to nearly the base. If the tips of the petals break off you NEED the front of that slug to keep peeling back. The tiny amount of explosive force provided by the little petals followed by a straight wound from a 30 cal front is not going to cut it.



Use the groves in the bullet to determine where you want the tips to break and to promote expansion by allowing the copper to "hinge"
 
I drew something and tryed to scan it.

Big hollow section right down bullet. Should easily deform inwards enough for rifling that normal TSX type groves are not needed. Deep Grooves used to allow bullet to "hinge" open and perhaps cause fragmentation up front. The thing will be light for it's length. Not sure about stability issues. Needs a big tip to cover that gaping hole.
IMG.jpg
 
Brobee I think you've got a nice balance there as far as depth of the hollowpoint goes.

The remaining shank is heavy enough to keep penetrating and that is way more important than energy transfer IMO.

The roughly flat nosed profile of the shank (especially in the annealed one with the slight mushroom) looks very nice to me and should allow for a fairly straight path although it did veer off near the end.

Further experimentation with annealing and cavity shape should prove interesting.

I like the plastic tips too. I agree, you need all the help you can get with copper bullets. Any idea what the BC is yet?

Good work you're doing here, keep it up. What will be the trade name, Bro Bees??

Re. the penetration vs. energy transfer debate: I think energy transfer is very much secondary in importance compared to penetration. Tissue must be damaged in order to kill and penetration must be achieved to damage tissue.

Consider that every time you launch a bullet your shoulder is subjected to the same energy that goes into the projectile. My 416 Rigby hasn't killed me with recoil....yet.

Consider someone being shot while wearing a vest. They receive 100% of the kinetic energy of the bullet but with no penetration the hit is (usually) not fatal.
 
After reading some of the above comments... massive fragmentation may put the animal down this might be great for pest control but for hunting... there will be alot of wasted meat.
I dont know about you but when I am hunting and butchering game I dont like to eat the meat that the bullet has hit, if you done your own skinning and butchering you know what I am talking about it just does not look very nice.

The goal here for a hunting brass solid should be expansion and retention of the mass.
Expansion of 1.5 times its original size
Velocity range of 3400-2000 fps...
Penetration of 30 inches

Dont forget alot of people are talking about penetration with the fragments... fragments are light and stop penetrating quickly if you hold 95% of the original bullet intact it has greater mass and should penetrate more...

I dont know maybe I am off my rocker just thinking outloud here.

hornady_GMX_150.png


3400fps 2700fps 2000fps
 
Back
Top Bottom