Copper vs lead

[StumpGrinder]

What is being discussed here, I believe, is terminal ballastics. I am just starting my deep dive into this topic. Muzzle velocity is discussed very often but I believe the twist in the rifle barrel is just as important. Hammer suggests, maybe even demands, that there is a minimum twist of rifling to use their bullets effectively. If the bullet "tumbles" when it hits I can't see how any bullet will work as advertised.

Bbullets that are designed to expand seldom tumble unless they have lost enough velocity to not perform as designed. Then they act like a Spitzer and will tumble. You can see this in videos where they are using pistol length weapons of rifle caliber and the round is not developing its designed velocity. Which mimics a long range hit. As all bullets shed velocity if they remain in flight long enough they will become unstable and yaw. It simply happens faster when it impacts tissue. This is the purpose of the twist rate, to keep a projectile stable longer but there are limits. The bullet expanding shortens it and therefore reduces the effects of yaw. Short bullets do not yaw as quickly as long pointy bullets. With a long pointed bullet the base is heaver and therefore will try to flip the bullet just like an arrow without feathers. The feathers on an arrow slow down the rear of the arrow to keep it flying straight. Bullet spin accomplishes this with gyroscopic force, but just like as a top becomes unstable as it slows down so does a bullet.

 

[StumpGrinder]

It's all been said before and what you say is mostly true. However, the lower density coppers eventually do Peter out. So if you are applying this logic make sure to consult your ballistic table it will tell you at which point the copper beats and eventually loses to a heavier lead bullet. There will almost always be a point where the lighter faster bullet no longer is equivalent. Personally, I shoot non-lead. For my 25-06 that distance is around 550 yards. For the Creedmoor 600 yards. All within the distances I want to be shooting game at. The 200-400 yard performance of the monolithics I'm shooting (hammers) is outstanding. Also as a lazyish reloader the consistency in dimensions of monos is worth it to me alone.

you are correct to a point however the longer lighter bullet will have a higher balistic coefficient and that Trumps weight to a great degree. This can be seen on another thread where I compared the 30-30 to the 7.62x39. Past 100 yds the higher bc of the 7.62x39 significantly out performed the 30-30 even though it started out 200 fps faster.

 

[shooters4h]

I'm not a fan of dropping bullet weight, just to gain a little velocity. However, if the ranges encountered will not be benefited with a higher BC, or the bullet will be solely used on smaller/lighter structured big game ....go with a little lighter bullet.

For our (wife and self) applications, with the potential for longer shots and a variety of game sizes and structure, we use mono's of weights resembling conventional cup and core bullets. Using the heavier bullets affords us, through better BC's, better trajectories, higher retained velocities and energies. From our limited experience, big (as in heavier) bullets appear to kill smaller big game just fine! memtb

A bullet that completely hose through a Animal does not translate into killing power like the old lead style bullets to many times I've had them pass completely through an animal and then lose the animal because the animal does not go down it's like shooting a solid I am not a fan of copper bullets and I've tried them over the years give me a good old Nosler partition any day

 

[trubkir17]

Velocity of the bullet isn't as much of a factor on stability as I thought. Playing around with the JBM calculator and moving velocity around by 1000fps doesn't affect the stability factor that much. Twist rate and bullet length have much more effect.
I am thinking that copper bullets are longer and most factory barrel twist rates start to go yellow or even red when you get to the heavier (and longer) copper bullets. This correlates with my own experience where it seemed counter intuitive that a 120gr barnes bullet performed much better on game than the 160gr bullet out of my Win70 7mmRM.

 

[StumpGrinder]

A bullet that completely hose through a Animal does not translate into killing power like the old lead style bullets to many times I've had them pass completely through an animal and then lose the animal because the animal does not go down it's like shooting a solid I am not a fan of copper bullets and I've tried them over the years give me a good old Nosler partition any day

To each their own but that has not been my experience with Barnes bullets however I'm not shooting long distances either. I'm well within the velocity window of the bullets ability to expand. Even the best jacketed bullet has a velocity window that it was designed to perform in. It's just like any other tool, yes you can drive a nail with a wrench but a hammer will do it better. Most bullet makers publish the velocity at which their bullet was designed to perform. Stay within those limits and most modern bullets do well.

 

[StumpGrinder]

Velocity of the bullet isn't as much of a factor on stability as I thought. Playing around with the JBM calculator and moving velocity around by 1000fps doesn't affect the stability factor that much. Twist rate and bullet length have much more effect.
I am thinking that copper bullets are longer and most factory barrel twist rates start to go yellow or even red when you get to the heavier (and longer) copper bullets. This correlates with my own experience where it seemed counter intuitive that a 120gr barnes bullet performed much better on game than the 160gr bullet out of my Win70 7mmRM.

You are correct but remember that as the forward velocity is slowing down so is the rate of spin. The two work togeather.

 

[lyotehunter]

One shot 175 gr.ELDX from 7mm practical. The elk in ny avatar, dead on it feet. Recovered almost against the skin. Bullets need good bc and shot placement. I have been a big game guide so I have seen a few kills with a lot of different bullets before all copper. If you shoot through a animal you lose a lot of hydraulic shock which kills.

 

[KSB209]

That 5th wheel is DRT too.

guess I shouldn't joke about someone else's lose but dang!

 

[Hespco]

Having guided a few elk hunters my self over the years, I see bullet placement as a prime consideration . When a C&C bullet is used successfuly it needs to be stated where the bullet entered. If it is a rib cage shot most any reasonable bullet will work as this is a soft target area on an elk. When a difficult angled shot is required my experience is the mono bullet has the advantage. We are not long range shooters . Most shots under 200yds, many under 100. We take one to two elk each season. Using the Barnes mono since 1994 we have never lost an elk. Can only recal two times whe a second shot was required. Never had a mono pencil thru. One elk hunter I remember I put on a 4x4 rag horn bull at about 80 yds, took 5 shots from his 30-06 using 180 gr Rem factory ammo to put the elk on the ground , then a 6th to finish him off. A very adequate cartridge/ bullet combo , but poorly placed. The vast amount of wounded & or lost game I have seen has been the results of long range shots. Some found, some not. Most reasonable cartridges with a tough deep penetrating bullet properly placed will work on elk. With the selection of tough bullets available I see no reason to use C&C bullets. My experience with the Barnes mono started back in 1994. Before then the Nosler partition was my bullet of choice.

 

[trubkir17]

I agree that velocity and rpm are directly correlated. I just don't think for stability it is that critical.
My rifle barrel has 1:9.5" twist. On Hammer bullets page the 140 Absolute Hammer states a minimum of 1:9.25" and the 172 Absolute Hammer states a minimum twist of 1:8". There is no place on their page where they state a minimum velocity. Now I am not going to use either of these bullets because the math just doesn't work. Everytime I have fought math, math has won.

You are correct but remember that as the forward velocity is slowing down so is the rate of spin. The two work togeather.

 

[lyotehunter]

That 5th wheel is DRT too.

guess I shouldn't joke about someone else's lose but dang!

I didn't mean for that picture to be in there .it flipped out of the truck and never damaged the bed that was visible. It was really windy.

 

[seattleman1969]

We are WAY raptor heavy, WAY, WAY out of control and the last reason to shoot copper, we've lost most of our Mt Goats in one unit because of the Eagles and they are the cause of all this Grouse issues, they need delisted and you get an eagle, wolf, grizzly combo tag!!

I am not concerned so much about the raptors although it is out there. I am more concerned with the amount of lead fragments in my food that my wife, son, and I are eating.

Look at those x-rays and CT scans in the article again and tell me you aren't concerned about giving yourself lead poisoning

 

[seattleman1969]

165 or 168 barnes ttsx will do all u ask in 308 or 300 wm

Or .30-06... my preferred elk load. 168 TTSX in 30-06

 

[RAGGED EDGE]

I saw it the opposite, when copper bullets were trying to make a new way to kill from cup and core they failed to deliver and now more mono have basically abandoned the old Barnes theory of killing and made their bullets kill by fragging and creating massive bleeding wound channels like cup and core they are taking of again and we are seeing very, very good stuff in the mono bullet world!!

Minus the added "benefit" of lead contamination.