Home Forums Hunting & Shooting Ask The Gunwriters Fresh Evaluation of the "Copper Bullets"...

Has anyone recently (within the last year) done a comparison of the new copper bullets by Barnes, Nosler, Hornady, and a few of the upstarts? It seems to me that could or would be an interesting comparison.

Areas I have interest in are:
Least barrel fowling
easiest to clean barrels after use
Most accurate
Depth of penetration could be looked at, however, with this style of bullet, do any of us really think one of them wont penetrate "DEEP".

John Barsness, have you done any of this of late ole buddy?

I've shot a bunch of the monolithics (and near-monolthics, like the North Fork) in to both media and game. There isn't enough difference in penetration to mean anything.

The plastic-tipped bullets of whatever brand tend to expand more widely, doing more damage. They also expand more reliably than hollow-point TSX's, especially in smaller calibers/.

As far as accuracy goes, they're all very accurate but on occasion a certain barrel doesn't like the E-Tip, probably due to the solid shank.

None of the recent bullets foul barrels any more than standard bullets.

All have proven somewhat sensitive to seating depth.

Do these bullets work at .308 Winchester velocities. What about results when loaded into a larger magnum case? Going on my first black bear hunt in Alaska in the fall and the .308 win and .300 win mag are the biggest rifles I currently have. I understand we will be hunting in an area inhabited by browns and penetration may be an important thing in an emergency. Would like to use the Barnes if they are available again anytime soon (we are having severe shortages of everything). Are these good choices or should I start looking for something with a bigger hole in the end of the barrel?

I have used 130 and 150 grain monos in both .308 Win and 300 WMs. They work quite well. A 130 grain TTSX in a 308 Win is an outstanding deer killer, and by far my first choice bullet for that job in that caliber. In 300 WM, a better BC (heavier bullet) can take advantage of the case capacity and extend range over the 130 grain bullet. If you will be staying inside 300 yards The 130 is fine. A 130 grain TTSX can produce excellent accuracy out of a .308 at 3050 FPS, and usually does.

Black bears are no harder to kill than deer.

In an emergency situation with a brown bear it will be almost by definition a close range problem. I have never hunted brown bears and have no desire to ever do so, but if I lived in their territory and had to be concerned, I'd be quite happy with a Remington pump in .308 Win or 30-06 with even the 130 grain TTSXs. They will easily get through to where they need to go while giving you the advantage of taking a more angled shot if necessary. My experience with them is that they are far, far less effected by bone than any lead core bullets I have used or seen used.

I suppose if I were hunting brown bears I'd probably opt for the 300 WM but I would need some convincing to load bullets heavier than 168 grains.

I suppose one consideration might be that bears have a tendency to being pretty fat and producing sparser blood trails, and the monos have a tendency to making about quarter size holes in the hide. I have seen enough instances of caliber size holes in the hide both coming and going, even while doing incredible damage in between. I guess I'd prefer something other than that happening for black bears which in my experience are shot at close range in the evening, after sunset. I don't know how to guarantee big holes in them though.

John,
Which one will expand to a wider frontal area at the lowest velocity?
Thank you!
Alvaro

Alvaro,

I'm betting the pure copper ones would expand easiest at low retained velocities, but much depends on the twist of the barrel and initial velocity.

Bullets shot from a faster twist barrel at a higher muzzle velocity retain most of their spin rate, even when velocity has dropped off. This helps them expand at, say, 1800 fps, when bullets shot from a slower twist at a lower muzzle velocity might not expand at all at 1800.

Thanks, John...........

I don't want to hijack this thread but could you please elaborate a bit why a faster twist rate would produce more expansion? I get the whole faster velocity thing but the twist rate is new to me. A 1:8 twist vs 1:16 twist on paper is twice as fast but we are still only talking 1 complete turn in 8 or 16 inches - more than the average thickness of a ribcage on most broadside animals.

Increased centrifical force.

Horizontal plane slows done sooner than the rotational plane.

I am not so sure I would buy that.

I don't think I'd buy higher RPM bullets (at least monos anyway) opening up better in animal tissue either. At least not without some pretty exotic testing to back it up.

In that we can spin a cup and core bullet fast enough to when combined with the friction heat from bore travel to disintegrate them in the air. We have no evidence of that same phenomena, nor indeed of any disintegration in monos. We do have evidence of shearing off petals in extreme impacts, but that's a wholly different thing.

I wonder if Barnes has video that might support this. they could well have video showing measurable wound channel size increase with increased RPMs at the same velocity. That might tend to support the proposition.

You're entitled to your opinion...the matter is pretty well settled.Mono's may not fragment,(aside from shearing petals which ain't such a hot thing anyway,depending on you viewpoint)),but that doesn't make them immune from laws of physics,and bullet material is still bullet material.If it's soft enough to expand,it's soft enough to be forced outward from rotational forces as well.

If I've done my math right, assuming 3,000ft/sec, they would be rotating at 270,000 RPM and 135,000 RPM respectively. I'm not sure how much that rotational force difference translates into the bullet opening, but that would seem to be a significant force. Out of curiosity, I wonder how much the force is different for a larger diameter bullet given the same rotation rate? Ex: a .243 bullet vs. a .338 spinning at the same rate. The outer edge of the .338 is further from the center of rotation. That's some serious ballistic gack to consider.

KE = Kinetic Energy
RE = Rotational Energy

Rotational Energy is very small compared to Kinetic Energy

I couldn't leave it alone. For an initial velocity of 3,000 FPS and a 1:8 twist, you get 270,000 RPM. The centrifugal force on a .338 cal. bullet would be 349,933 Gs and for a .243 Cal. bullet 250,544 Gs. Don't know if that's meaningful to a copper bullet.

Do you have a reference for how and who settled this? I's be very interested.

You get more spins in the critter with a faster twist. Again, the horizontal plane slows much sooner than the rotational plane so are getting more buzz saw [bleep] happening inside.

So, the greater the velocity the greater the KE at impact (we all knew that). But the higher the twist the greater the force pulling the bullet apart for a given velocity and the larger the bullet the greater the force trying to pull the bullet apart. No idea if that rotational force is meaningful. Meaning, does it approach the structural integrity limit of the bullet where more force equals greater opening.

Back to the OPs thought though, I would like to see some form of apples to apples comparison of the various monos impacting near 1800 FPS and see how different they are.

This makes some sense, and it forms the basis for my question of Bob. From the videos I have seen of Barnes in gelatin, it looks reasonable that there is more damage with more RPMs. My question about greater expansion bears on this in a big way. Right now were are tinkering with copper bullets in rifles designed for lead bullets. If more RPMs = wider expansion, AND more RPMs = more damage, then we have motivation to look for the top end of what we can do with RPMs.

If i can get 3000 FPS out of a 9 twist barrel pushing a 55 grain bullet, then can we gain equivalent tissue damage to say for sake of argument, a 3600 FPS same weight bullet by simply going from 9 twist to 5 twist at 3000(not that either is necessarily likely)? If this is true then we need to know what we can accomplish using bullets that won't come undone by over rotation, and what if anything radical twist increases might do to pressure.

It comes down to asking the question what happens if we design a barrel to take maximum advantage of designing it for copper or guilding metal bullets exclusively.