Project - Machine Turned Solids

Brobee

Brobee

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Hello everyone!

One day while cleaning up my garage I stopped to think for a bit after handling my armoured plate gongs....they were coated in very fine lead splatter from my centerfire rifles. After reflecting on how much I'd been shooting them (alot) and remembering the splatter patterns out on the range I started thinking about how much lead dust I was creating and bringing back home with me after every range session. Given the two little ones now running around and construction of a new private rifle range on some agricultural land the wife and I just aquired I committed to seriously investigate going lead free.

After being somewhat dissapointed at the slim pickings of what was at the time commercially available (not to mention the price!), I set out to see how hard it would be to have them made locally and wound up with my summer/fall project. Woohoo!

So I did up some basic drawings and shopped them out to some local screw-machine-equipped-volume-production-small-parts shops; I found an outfit willing to play ball and we went through several prototypes. First out of the hopper were two solid tip designs intended for use in my .308 M1A/M14s and my .224 Swiss Arms Classic Green. We went through several iterations primarily monkeying with the fouling band depth/gemetry and boattail geometry and now have something that seems to work reasonably well.

Material wise they're machined from solid copper that has been alloyed with some exotic trace metals to improve machinability. It was a b*tch to source material, and I was very surprised how expensive it is. If I get set up to make a zillion the only way it would have a hope of working out would be to commit to a complete mill run of material (aka - $25k worth per diameter of material run...yikes!!) so the project warrants careful study before taking a step like that

The .308 projectile weighs in at 155 grains with an S10 secant ogive and a slightly rebated boattail. Despite not being able to seat the bullet long enough to touch the lands of my M14S while still making magazine length, in all three of the M14 type rifles I've seriously tested with my new bullets they perform better than my standard 155gr Sierra HPBT match loads...woohoo! I've only shot them out to the limit of my rifle range (which is 500 yards), so I don't know how they perform at longer range.

The .224 projectile was designed with a 62gr target weight with an S7.3 slightly secant ogive and slightly rebated boat tail. I can't tell the difference in accuracy between them and my 69gr HPBT match standard fare load for my swiss rifles, but they shoot well and I'm happy enough with them to give them a longer term test.

Early in the project we made some up with standard boattails for comparison, however in my testing I could not get them to fly as accurately as the rebated boattails (don't know why) so I stuck with the rebated design.

I did a larger run (5000 bullets) for my own personal use as well as to try and understand the economics of mass production; the shop is still studying their learnings from the machine runtimes and program sequence (they're run on two separate axis so there is no partoff nipple like what you see on the backend of the barnes solids) to try and figure out what their bare bones price is; it's way premature to try and speculate as to whether or not they're commercially viable and would be made generally available. If the numbers come back and they look like they are in the ballpark, I'll go through the appropriate motions to get setup as a dealer and then get setup to sell them but in the meantime I'm good to go for a bit on my range while I do some longer term testing.

The solids are very gentle on my steel targets; moreso than any hollow point shot at similar velocity. I speculate that this is because there is no small pocket of air that gets compressed and then released at high temperature.

After getting the kinks worked out of the solids we did up some .308 hollow points just in time for hunting season. They were based on the solid profile but elongated in the rear driving band to accomodate material theived from the front end to make the hollowpoint. The cavity was initially drilled and then broached with a hex head, the idea being that hopefully the tip would shear along the corners of the hex head to behave like the barnes bullets do in tissue. For the tip we spun up some UHDPE to the profile of the original tip with a long stem for stabbing into the hollowpoint. My intent was to try and recover one from an animal shot this hunting season, however everything I dropped the hammer on (2 whitetail and 2 mule deer) wound up with complete penetration and no bullet recovery. There was no evidence of multiple exit wounds so I speculate the bullet is holding together well however I was dissapointed not to be able to report with a photograph of a recovered bullet amd admitantly my sample group is very small. Exit wounds and internal damage seem analagous to other animals I've seen shot with Barnes bullets. I've got some gelatin en-route to mix up early in the new year where I'll recover a bunch to see what's going on, both in the expansion world as well as a more observation based study of the fouling band performance and will report back as I go.

Regarding the tips - they were surprisingly a b*tch to machine (more of a material sorting problem...how to recover the tips from the chips but also some partoff issues with small ribbons remaining) and there is definately more work to do there before the hunting bullets would ever be commercial. They did work very well vis a vis functioning in my M14...I have a couple rounds that have been stripped by the bolt, rammed into the feed ramps, and then not fired to be used another time...the tips hold up well enough that there is no deformation or change in concentricity. All in all very happy with them other than reported difficulty in manufacturing. In our next batch we may try some delrin to see if it is any better. If money were no object I'd make them out of aluminum.

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Anyway...I thought I'd make a post here about my fall project and see what you folks had for feedback! Critisism (preferably constructive) is encouraged....:) Profile would be easy to change (ie: making a less aggressively tapered ogive designed for closer seating proximity to the throat/rifling while still making 2.800 for magazine length...I have my own thoughts on this but thought I'd throw it out there for other folks to weigh in on).

Enough of me blabbing....what do you think??

Thanks for looking/reading,

Brobee
 
That's just awesome. Are you retired or somehow independently wealthy and have a lot of free time?

This is a major project and I love that people do this as a hobby.

If it goes commercial at all I would love to test drive the .264 or the .458's.


Good job.


Ryan
 
Thats Awsome!!!

Have you looked into getting a mold made for the tips, instead of having them turned.

Id try out the 224's if available.
 
I love this ingenuity. Fantastic work!

My question is how much does this foul the barrel? What would be the difference in barrel life, if any? If the Al were ever made, how does one go about cleaning that out of the barrel?
 
Very well thought out and executed. With respect to a game bullet, I have some thoughts . . .

With respect to the terminal performance on your deer, I suspect that your bullet failed to expand, swapped ends (resulting in a large wound volume) and exited backwards. Had the depth of your hollow-point allowed for 1.5X expansion, perhaps the nose cavity was too small, if the cavity behind it was not tear shaped like a Barnes hollow-point. In any case the tear drop chamber in the Barnes bullet appears to prevent plugging as the bullet passes through the hide, after which fluid drives the expansion. In earlier X bullet designs, expansion was hit and miss, and I recall purchasing boxes of bullets with different sized nose cavities which suggested to me at that time that the folks at Barnes were attempting to work out the optimal nose cavity design. While not what you intended to design, a larger frontal cavity filled with pure lead would solve the problem of the bullet being tail heavy, while retaining an aerodynamic shape, and would result in good controlled expansion qualities, particularly if you bonded the core with the jacket. The other way to get good terminal performance on game is to change your design to a true big game solid, with parallel sides and a flat or hemispherical nose.
 
I realize you said you have balistic gel on the way but in the mean time, I was told that a box of paper soaked in water will act similar to tissue when shot. I don't know if this is true but worth a thought. By the way very cool and worked out plan. Many people talk about stuff like this but few make it passed the talking stage. I tip my hat to you sir!
 
unstableryan:

no, not retired yet; I am a day job working stiff with two beautiful little kids (2 and 4), a wife who stays home with them and alot of school/activity stuff coming our way. We try to save/invest what we can, and a certain portion of what we do is earmarked for what we call "investing in our own ideas instead of someone elses". My argonaut armament 870 stock adapter was financed this way as are some other projects we have on the go. I find that having a project like this keeps the fire burning inside a bit more...

firemachine69:

most of the initial prototyping iterations were focused on reducing barrel fouling to acceptable levels. Initially we experienced heavy fouling however after several tweeks in fouling band depth, spacing, and width what we have now does not seem to foul my chrome lined M1A barrels any more than the sierra bullets do. Regarding your aluminum question - I would only consider using this material for the tip, not the bullet body itself so there would never be any aluminum in contact with the bore. The issue with aluminum is that it costs more than the machinable plastics (both from a material perspective as well as the comparatively much more time it takes to machine them)

re - other calibers:

These are still a ways out however certainly on the radar. One thing I need to try and get a handle on is whether or not there is any real demand for the solid (non-hollow point) bullets as they will be comparatively quite a bit cheaper than the polymer tipped hunting rounds. As the bullets are machined from solid copper they will never have as good ballistic performance as denser conventional copper jacketted lead bullets. Being longer for the same weight they're more susceptible to wind deflection as well as more difficult to stabilize (resulting in greater chance of tumbling at extreme range). So the only niche they really fit is for someone willing to sacrifice some ballistic performance in exchange for eliminating lead from their range. I like to shoot primarily in service rifle type conditions at steel silhouettes at ranges between 100 and 500 yards, so the decreased ballistic performance does not really come into play much and is worth sacrificing for keeping my property lead free. For people shooting for group size at long range my copper solids are likely not the best choice, as there will be real performance benefits to using conventional jacketed lead. I guess what I'm driving at is that careful thought would need to go into how to market them, which is predicated on the notion that there is some real need/niche serviced by them. The primary advantages they have is that they are lead free (and as an aside brass or bronze isn't ....while being a cheaper material all the free machining brass/bronze readily available has some lead in it, usually around 3 to 7%) and machine turned (more consistent/tighter tolerance than swagged bullets). Whether or not folks are prepared to accept those as advantages and then pay a premium over lead bullets will dictate whether or not other calibers ever come to light.

To run off on a tangent a bit, I looked a bit at lead-free-yet-still-dense powdered metals (like bismuth or tungsten) compressed into a conventional jacket however the denser powdered metals were very much cost prohibitive. I'm still looking at copper compressed into a copper jacket which is not unlike the barnes varmint grenade or their new MPG bullets, however ballistic performance of these bullets is even less favorable than the machine turned solids I'm currently playing with. The key advantage to going this way is cost....powdered copper compressed into a copper jacket and then swaged to final shape would be about 2/3 to 1/2 the cost of the machine turned projectiles. For folks shooting stuff like ipsc rifle at ranges less than 200 yards they would be the lead-free-cat's-a**, but from 300 to 500 yards I suspect their performance would drop off drastically and past 500 they would shoot like cr*p.

I suspect the best niche served would be the hunting crowd which means that the most amount of work needs to go into the expanding bullet design. To gain some understanding of what's gone into what's currently commerially available I puchased and sectioned pretty much everything I could get my hands on. I've been hunting with Barnes ### bullets the past few years and have had excellent success with them so they were my starting point; but no matter how hard the machine shop guys and I racked our heads we could not come up with a way to reliably broach such a small-yet-deep cavity when turning them on a lathe. Our design wound up being more along the lines of current polymer-tipped-solid-copper-hunting bullets, such as the Barnes tipped TSX, Nosler's E-Tip, or Hornady's GMX with the exception that we drilled/broached the cavity rather than swaging it over a mandrel. I think that ideally a 4 point broach would be bette than the 6 point hex head we used, as the petals might be less likely to shear off when hitting hard stuff like bone but don't really know as I've done little testing and am ill-equipped to do so other than shooting the odd animal with them and taking careful notes. Also, the 6 point hex broach was what the shop had on hand and I elected to avoid the cost of fabricating a custom broach.

jmiddy:

I did look at injection moulding the tips, however when I gave my tolerance specs on concentricity and uniformity to the injection moulding guys their price went through the roof. I might go further down this path once we get the hollow point sorted out, but for now we'll be sticking with machine turning the tips from some sort of plastic. The machinist tells me that delrin turns much better, so depending on cost we might try that in the next batch.

Boomer:

I've seen lots of wound channels caused by lots of different types of bullets; I don't believe that what I saw in the 4 deer shot with the tipped hollow point would indicate the bullets were tumbling - the wound channels were straight as an arrow (even the few that broke the humerus or scapula on the way in) with no deflection. I believe the tips are tearing but don't know if it's along the corners of the broach line or to what extent along the depth of the cavity as the broach is only inserted about half of the 0.400 total cavity length.

Boomer does make an intriguing suggestion though and something I've been seriously considering....a non-spitzer designed solid with a massive flat front metplate, something along the lines of what lots of african hunters use for dangerous game. It would have crappy long range ballistic characteristics but awesome penetrating power (and very interesting expansion charracteristics). GS Custom Bullets in New Zealand has done this in their FN line. I did not go this route as I was unsure they would feed ok in my M1A and did not want to blow my seed cash on something that I could not shoot ad-nauseum (have yet to shoot to the point I'm nauseous, but will advise on round count if it ever happens) through my favorite gun on my lead-free-range. I think though that it's an awesome hunting bullet design and if our lead free bullet project ever gets self sustaining legs I'll be trying it for sure. I do have a drawing so once I do another run with the machine shop I might try to convince them to use some small portion of the next batches material to prototype the concept.

Again, feedback is encouraged!

Thanks for reading,

Brobee
 
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VERY interested....domestic bullet manufacture is a GOOD THING, especially lead free!

You should apply for a government grant on this as an Environmental issue, (get funding for R&D) and see if you can get it to the commercial level.

Seriously.

I mean, if the price was reasonably close to what a regular match grade round would cost, with the Made in Canada option, and the Environmentally Friendly card, you've got some good selling features.

NS
 
As for your problem with the tips... I am pretty sure that the big players out there hornady etc... stick a polymer ball or shape in a die and they press the tip in place and shape them that way.

Its like a swaged lead bullet they take a hunk of lead and use a press to press it into the desired shape that way they can precisely control the weight of the bullet unlike casting.
 
Brobee said:
I think that ideally a 4 point broach would be bette than the 6 point hex head we used, as the petals might be less likely to shear off when hitting hard stuff like bone but don't really know as I've done little testing and am ill-equipped to do so other than shooting the odd animal with them and taking careful notes. Also, the 6 point hex broach was what the shop had on hand and I elected to avoid the cost of fabricating a custom broach.
Click to expand...

This isn't necessarily a bad thing! If fact, one of the first things that I noticed was that your bullet has six expansion points rather than 4, like the Barnes bullets have. This means that there will be more surface area of the bullet, and even if the smaller petals shear off a little bit easier than if there were 4 large ones, that can be a great thing! The most recent bullet technology, such as the VLD and CS custom, supports the idea that a fragmenting bullet kills quicker than a non-fragmenting one. People's usual complaint with the Barnes bullets is that they allow the animals to travel too far after being shot. Your bullet would offer the best of both worlds- the small petals would fragment easier, giving quicker kills, and the shank of the bullet, as well as any remaining petals, would continue to penetrate just as deep as Barnes bullets do. That is an excellent selling point over the Barnes stuff! Quick killing AND deep penetrating. This is similar to recent assessments of the E-tip, which is said to expand a little wider than Barnes bullets, and penetrate slightly less, only your bullet does it with a better design, IMO. You can simultaneously appeal to the VLD and BT crowd, as well as the TSX crowd.

Pathfinder has a good idea. It sounds like you need more testers, or more opportunities to test your bullets' for expansion, penetration, accuracy, and on-game performance. I would be more than happy to buy some bullets from you (as long as the price isn't too crazy) and help you test them by using home-made expansion and penetration tests, as well as during my big-game, varmint, and target shooting seasons.
 
Jordan Smith said:
Pathfinder has a good idea. It sounds like you need more testers, or more opportunities to test your bullets' for expansion, penetration, accuracy, and on-game performance. I would be more than happy to buy some bullets from you (as long as the price isn't too crazy) and help you test them by using home-made expansion and penetration tests, as well as during my big-game, varmint, and target shooting seasons.
Click to expand...

Yes, of course we're not expecting handouts as these things arent' made out of nothing and shipping is expensive. The more testing the better.

I think a good size black bear @ 30 yards would make a good testing recipient :)
 
You running the broach straight in?

I got the impression that the Barnes ones were broached or punchformed, then swaged down a bit at the tip. That is just from looking at the tips, have not cut one up.

Looked at any of the commercially available bronze alloys as potential stock? Should be close to the copper alloys in cost, may be a bit denser.

Looks good! Sounds like a way to turn a buck off obsolete tech, if you have the time to muck about with screw machines and automatics.

Cheers
Trev
 
I buy premium hunting bullets for reloading because they are more accurate (in my 14) than the cheap stuff and large groups drive me nuts.:mad: If you can market these cheaper or comparable to the premium bullets I would gladly buy them from you, especially to support a Canadian venture. Good work so far and I look forward to hearing more.
 
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