A thought, keep the dimensions of the experimental BH 100gr bullet, but make it out of copper alloy. That will make it lighter, and allow a higher velocity. If its true that length is the most important cause of tumbling and fragmentation.

The only thing I am thinking is that Copper might be just ENOUGH harder the copper jacketed lead to not snap, or to bend rather than snap.

Any thoughts?

FYI,
Copper is lighter than lead therefore the same weight bullet in copper will be longer thus less capcity in the case left over for powder.

Now if you want to talk about brass or tungsten than that's a different story. Otherwise the same size "all copper" bullet you suggest wouldn't weight 100gr but rather 80gr.
Best,
Sec1Ops

I would say that this is a correct assumption.
I have shot the copper Barnes bullets from a .270 into a chunk of mild steel and it seemed that they penetrated farther than the lead core bullets.

Yes, that is what we want. We want something that fragments like the 100gr but weighs less so we can get the flat trajectory back again.

Copper isn't going to fragment, and if you make it barnes x type, it *might* be decent.  Actually it would be should better than any other controlled expansion round .224 bullet.  If you can imagine 4 long strings of copper connected to a long shank, of course, how long the strings of copper would be dependent on velocity.  Or you could just have a 75 grain hornady.  Or a 100 grain BH.  I don't see what is so bad about the trajectory.  It in NATO pressure , it was hypothesized that it could go up to 2600 fps with no problems.  Even if it was only 2500 fps, it is starting out faster than most 7.62x39, and with a bc in excess of .500, it is going to shoot considerably flatter shooting than any loading of 7.62x39.  

It was made to be a very lethal load for short barreled operators.  Ballistic testing has shown to be promising.  Lead fragments, copper is tough.  5.56 lethality relies on tiny fragments impacting the inside of a tightly streched temporary cavity creating a wound far in excess of a controlled expansion round.

Nothing against copper as a bullet material, just not in this sort of application.  And if you want to experiment, just get ahold of an experienced reloader and your local machine shop, cnc would definately be better due to tolerance and higher volume for testing.  Everyone would be overjoyed with the testing of soemthing like that.

whisper

check out this thread.
[url]http://www.ar15.com/forums/topic.html?b=3&f=16&t=162448[/url]
Near the middle of the first page is a discussion similar to this one.

Take the nickle and zinc out, use pure copper, moly coat it to prevent copper fouling in the bore.

For copper solids Lost River Ballistics makes some serious VLD bullet designs that are likely comparable in exterior dimentions to that of a 100grain lead .224 bullet.   Long enough that their 80 grain VLD requires faster than a 1:7 twist.


As for what an all copper or bronze bullet would do on steel compared to a lead bullet, I'm about to find out when I try some Barnes 165grn and 125grn Solid Spire Points to see how they compare between a 165grn AP at 3100+fps and a 190grain Sierra MatchKing at 2900fps.