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solid copper bullet performance

 
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  #8  
Old 10-01-2013, 01:22 PM
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Re: solid copper bullet performance

Beng's explanation was spot on.

SD is a function of mass and cal. A 180 gr .308 cal bullet copper bullet has the same Sectional Density as a 180 gr .308 lead core bullet. The dfferense is in the density of the material (specific gravity). If both bullets have about the same form factor, the copper bullet will be a little longer and have a slightly lower BC because being longer, it will induce more drag. It will also require a tighter twist rate.

Just like lead core bullets, mono metal bullets have different terminal characteristics depending on the design and material of the bullet. They are made from different hardness of copper and the E-Tips are made of guiding metal very similar to jacket material. Some have tips and some have hollow points.

I am one of the few who do not have a personal preference based on what the bullet is made of. The bottom line for me is, 1) How well my rifle likes them - accuracy 2) Terminal ballistic characteristics 3) External ballisitic characteristics - BC to weight/SD to velocity 4) Cost

As of yet there is no perfect bullet for every situation.

The cup and core bullets in the 338 cal and down have a little better BC to SD factors than the monos. When you get above 338 cal, that starts to change.

Mono's tend to be more controlled expansion and are better at penetrating bone and dense muscle.

Cup and core bullets range in controlled expansion types (Bonded, Partitions, A Frames, etc) to highly frangible (Bergers, Amax, etc). The more frangible, the more damage they will do in soft tissue like lungs and liver but the less likely to penetrate dense muscle and bone.

I do lean more toward controlled expansion thinking, but the vast majority of my shots are lung shots and the best bullet for that is a Berger. But... in the rare case i have to make a quartering shot through muscle and bone, I would feel better with a controlled expansion type bullet. The question is, which is most practical overall?

I used to load E-Tips for short to mid range hunting and Bergers for longer range.

Of all the mono's I like the, the GSC HV bullets the best for terminal ballistic design but I could not get the 308 177's to group less than MOA out of "my" rifle. There is very little room for seating adjustment with them and unless you have a very short throat they make a big jump to the lands.

In my new 300 RUM, I will be trying 230 Bergers, 200 CEB's and 177 GSC HV's. All these bullets will perform well terminally to well past 1000 yds. The 230 Bergers will have the clear advantage past 1K. Accuracy will be the first consideration in selection. I may even go with a 2 load line up again to cover all the bases.

CEB terminal performance

Cutting Edge Bullet Kills

Cutting Edge Bullets terminal performance

*Updated 10/29* Terminal Performance 6.5mm 130gr CEB

GSC terminal performance. The GCS conceept is lighter bullets, higher velocity which doesn't work well with cup and core bullets.

GS CUSTOM BULLETS - FAQ - Expansion and Weight Retention

Of the mono metals, I like CEB and GSC the best.

Advantages and disadvantages of each.

CEB's seem to be easier to load for accuracy, but my experience has been limited.

CEB's are about 2/3rds the cost of GSC's

CEB's are quicker to order

GSC's probably have better terminal performance including lower opening velocities down to 1600 fps. However, the lower opening velocity is due to a larger hollow point meplat opening, which degrades BC. I base the terminal performance assessment on what I've read, no first hand experience yet.

GSC's can get a little more velocity than CEB's of same weight based on my experience, about 30- 50 fps more

Both CEB and GSC will make custom projectiles to your specs.
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  #9  
Old 10-01-2013, 08:58 PM
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Re: solid copper bullet performance

Awesome information. Thank you! I have read Bryan Litz's book cover to cover. He was really down on Barnes because of sectional density and grooves. I have shot them and they perform really well as far as accuracy, but not sure on terminal balistics long range.
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Old 10-02-2013, 12:48 AM
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Re: solid copper bullet performance

Hey Mark,

I just ran #s on the 230 berger vs the 177 GS. I guessed that you would run the Berger @ 2900 fps??? and the GS @ 3500 fps. Just got done running it in a 30" a couple of days ago to 3600 fps with H1000. But at the two velocities that I used the Berger does not catch the GS in drop or the most important windage all the way to 2000 yards. The Berger Has 2 more ft lbs of energy at 1300 yards. At 1500 yards the GS is still traveling at 1593 fps the Berger is at 1406 fps. I am not sure where the clear advantage of the Berger comes in at long range. At 1500 yards the Berger has 1010.5 ft lbs of enrgy vs the GS @ 997.4 ft lbs. I think that may be further than either one need be shot at big game. Just my .02

Steve
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  #11  
Old 10-02-2013, 02:59 AM
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Re: solid copper bullet performance

Just stay way inside the min speed limit and shoot the harder parts of your prey. That way ttsx should work even at long range. Don't expect bang flop results though, ttsx bullets are designed to undergo only limited sd changes in the target medium, thus and because of the loss of velocity, energy release will be limited too. Especially compared to rather frangible lead core bullets.
A fragmenting design (like the GS or german MJG) should be superior at long range. Im talking just theoretically though.
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  #12  
Old 10-02-2013, 07:35 AM
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Re: solid copper bullet performance

Quote:
Originally Posted by stevotary View Post
Awesome information. Thank you! I have read Bryan Litz's book cover to cover. He was really down on Barnes because of sectional density and grooves. I have shot them and they perform really well as far as accuracy, but not sure on terminal balistics long range.
The Barnes bullets are OK, but they just don't have the BC's that other bullets do for long range. If I was shooting at short to mid ranges only they would be a viable option. That said, I like the E-Tips better for short to mid range hunting.
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  #13  
Old 10-02-2013, 08:16 AM
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Re: solid copper bullet performance

Quote:
Originally Posted by RockyMtnMT View Post
Hey Mark,

I just ran #s on the 230 berger vs the 177 GS. I guessed that you would run the Berger @ 2900 fps??? and the GS @ 3500 fps. Just got done running it in a 30" a couple of days ago to 3600 fps with H1000. But at the two velocities that I used the Berger does not catch the GS in drop or the most important windage all the way to 2000 yards. The Berger Has 2 more ft lbs of energy at 1300 yards. At 1500 yards the GS is still traveling at 1593 fps the Berger is at 1406 fps. I am not sure where the clear advantage of the Berger comes in at long range. At 1500 yards the Berger has 1010.5 ft lbs of enrgy vs the GS @ 997.4 ft lbs. I think that may be further than either one need be shot at big game. Just my .02

Steve
Steve,

In a nitrided 27" 300 RUM barrel with RL33, I'm expecting close to 3200 fps with the 230's. In my old 26" Sendero barrel, I was getting a little shy of 3500 fps with the 177's with both Retumbo and RL17, however the RL17 load was less than 90% capacity. I'm thinking the nitrided barrel might be a little friendlier to RL17 and the 177's and might see 3600 fps or so. I'm also a little skeptical of the BC claim for the 177. I think it's probably in the mid to upper .5 range and time should tell on that soon.

If I use .6 and 3600 fps for the 177's and .74 and 3200 fps for the 230's, the 230's catch the 177's in velocity @ 1300 yds with 53 gr more mass. At 1K the 230's have a 400 ftlb of KE advantage over the 177's and even better relative momentum advantage. The 230's take the windage advantage from the get go although it is close through out with a 10 mph corrrection of 5 MOA for the 230's vs 5.6 MOA for the 177's @ 1300 yds.

The 230 Hybrids are going to be hard to beat in the 30 cal down range. In fact they are the best LR bullet ballistically in the 30 cal. If accuracy is equal between the 2 I have to go with the 230's. The only possible advantage the 177's would have is closer range penetration through muscle and bone and in that case, the 200 gr CEB's would be at least equal and probably better than the 177's.

Back when the 210 VLD's were king of the heap so to speak, the 177's would have given them a lot better competition. The 1600 fps opening velocity is a big plus when it comes to deer size game, but not sure how much advantage it is in trying to use a 177 gr bullet on elk size game at those lower velocities.
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  #14  
Old 10-02-2013, 08:31 AM
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Re: solid copper bullet performance

That would be amazing velocity for a 230. I have not heard of many getting that from a 200g AB with that barrel length. Given this kind of performance with the 230 berger you should be able to run the 177 up around 3700fps.

The faster you push the GS the better the bc should be. As it slows it will degrade. When you get up over 3500 fps this should be so.

If the Berger sheds half it's weight in the first few inches you are left with 115g to finish the job. VS 142g in the GS at 80% retention. Momentum is definitely on the side of the GS.

Steve
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