Bullet Penetration

[Jerry D]

With all the 6.5mm bullet hype, assuming the bullet is the same design, traveling the same speed, with similar SD, can we assume penetration will be similar With different calibers

140 6.5 accubond vs 180gr .308

130gr tsx in 6.5 vs 165gr .3089

Other than a larger wound channel, can the 6.5 get the job done.

I see guys using 6.5prc to 1000 yards, it's 300 fps faster than the cm. At the same impact velocities the 6.5cm can still really reach out there.

For bears and big animals, if the smaller bullet penetrates as deeply, is the larger wound channel going to kill faster assuming similiar shot placement.

How about a 6.5 140 gr accubond at 2750 fps vs .338 200gr accubond at 2650 fps

I am really interested to hear if a 6.5cm with a Barnes tsx or a 130 lrx can penetrate with the bigger guns or go deeper.

130gr 6.5 tsx vs .308 180gr parition or accubond at the same speed as each other?

Thanks for opinions, assuming same speed please rank the bullets as far as penetration goes.

Thanks again

 

[cohunt]

Check with the manu ... I know that not all ttsx are created equal. They open at different speeds/have different minimum opening specs. In .308 the 165s are different from the 168s , and the lrx are definately different from std ttsx bullets. Not sure about nab, but the lrab are different from std nab bullets.

165s are 1800fps minimum opening speed, and 168s are 1500fps

 

[26Reload]

I have used 168lrab in 280ai...142lrab in 65284...140ab in 26nosler.....
Have had bullets in each weight travel full lenght of deer...and retain substantial weight....and found several after their travel...
Plenty happy....
But never used any other bullets or calibers....found no need...

 

[Jerry D]

Thanks for feedback.

I guess the whole point of the topic is basically, if the bullet is the same design, with a similar SD, travelling at the same speed, penetration can be assumed to be similar as well, even if the calibers of the bullets vary.

People probably considered a 180 cup and core bullet from a .30-06 or .300 win mag enough for bears years ago, with the new bonded and copper bullets, a 130-140 6.5mm should have as much or more penetration but the wound channel may be smaller.

 

[Westernhuntr]

Thanks for feedback.

I guess the whole point of the topic is basically, if the bullet is the same design, with a similar SD, travelling at the same speed, penetration can be assumed to be similar as well, even if the calibers of the bullets vary.

People probably considered a 180 cup and core bullet from a .30-06 or .300 win mag enough for bears years ago, with the new bonded and copper bullets, a 130-140 6.5mm should have as much or more penetration but the wound channel may be smaller.

If you're asking whether penetration equals trauma without regard to weight or wound chanel then I'd say definitely not in my experience, at least when it comes to long range.
I've shot 3 bulls and a bunch of bucks with a 6.5 saum and there's definitely a lack of killing power compared to heavy 7's and 30's beyond approx 4-500 yards.
For closer shots a bonded bullet ( In my experience 140 partitions) will drop a bull in it's tracks, even with a center shoulder shot.
My wife just took bull #4 with that combo last season, center chest shot at 100 yards.

 

[WildBillG]

Another thing to remember is how the heavier bullet will retain momentum after impact. On that note one could say the smaller diameter bullet will have less drag. You did say though travelling the same speed. I would give the nod to the larger caliber bullet doing a better job. I do like the 6.5's but believe they have their limits.

 

[LVJ76]

In my experience heavier and bigger bore will kill more effectively.

Now bullets have changed a lot in the las 30 years, bullets now can expand quicker and destroy an animals vitals and drop them in their tracks without exiting the animal, shoulder shots aren't always needed to anchor an animal anymore..

In my experience a cup and core will kill more effectivley than a monolothic bullet. Mono's sometimes fail to expand when not used properly, cup and core can also fail but are more forgiving.

The larger the bore the bigger the wound channel therefore faster blood loss. Heavier bullets also tend to penetrate more. Today's many bonded bullets with higher BC's offer an option to make smaller caliber cartridges more effective, there's more weight retention and with it more penetrarion, this bullets however also make the larger bores more effective.

Bigger is better and heavier for caliber bullets are better as well. I'm not saying a 243 Win or a 6.5 CM are bad, they aren't, but in my experience a 7mm or 308 caliber cartridge kills more effectively.

 

[Ingwe]

I do like the 6.5's but believe they have their limits.

Not to some of the guys here

 

[ShootMo]

Speaking specifically of the wound channel---that's really the paramount factor in killing performance of a bullet. The more devastation a bullet creates as it's passing through vital organ tissue, the quicker the animal will expire. So even with identical speeds, identical S.D.'s, and similar bullet profiles, a more dynamic wound channel always gets the nod.

 

[entoptics]

Just a little data to illustrate "bigger is better", at least when comparing bullets with equal penetration, velocity, and relative expansion.

Caliber	1.5X Diam	1.5X Area	% more than 6.5 mm
0.264	0.396	0.123	0%
0.277	0.416	0.136	10%
0.284	0.426	0.143	16%
0.308	0.462	0.168	36%
0.323	0.485	0.184	50%
0.338	0.507	0.202	64%

While the 30 cal is only 1/6 larger diameter than the 26, after 1.5X expansion the frontal area is 1/3 more.

Even without the consequences of the temporary cavitation, more and larger bullet fragments, and greater energy transfer of the larger bullet, you're at minimum still going to "core out" a 1/3 larger hole.

 

[JASmith]

There is a fair bit of evidence suggesting that the primary driver of effectiveness given a hit in the vital zone is bullet weight. The velocity part is simply that the bullet must hit within the window of reliable expansion. This is independent of caliber. In other words, a 130 gr 6.5 bullet will be as effective as a 130 gr .30 caliber bullet of the same design class and both hit within the velocity window.

For more, go to: http://shootersnotes.com/ideal-bullet-weight/

 

[Snowboy]

With all the 6.5mm bullet hype, assuming the bullet is the same design, traveling the same speed, with similar SD, can we assume penetration will be similar With different calibers

140 6.5 accubond vs 180gr .308

130gr tsx in 6.5 vs 165gr .3089

Other than a larger wound channel, can the 6.5 get the job done.

I see guys using 6.5prc to 1000 yards, it's 300 fps faster than the cm. At the same impact velocities the 6.5cm can still really reach out there.

For bears and big animals, if the smaller bullet penetrates as deeply, is the larger wound channel going to kill faster assuming similiar shot placement.

How about a 6.5 140 gr accubond at 2750 fps vs .338 200gr accubond at 2650 fps

I am really interested to hear if a 6.5cm with a Barnes tsx or a 130 lrx can penetrate with the bigger guns or go deeper.

130gr 6.5 tsx vs .308 180gr parition or accubond at the same speed as each other?

Thanks for opinions, assuming same speed please rank the bullets as far as penetration goes.

Thanks again

I always suggest shooting the largest caliber that you are comfortable shooting accurately. The potential energy transferred by a larger diameter bullet seems to do more damage. That being said I have never needed more than a .30 caliber round for my deer and moose.

 

[Chase723]

Will they kill equally emphatically? If you shoot something in the head or spine then yes. If you shoot them somewhere else then no. Is dead, dead? Yes. But energy on target and energy transfer matter when it comes to emphatic killing. You also have to ask yourself though if that matters at all to you. To some people it does, to others it doesn't. What's the terrain like where you hunt? Do you care if something runs 50-100 yards? What about 200-400? Will you be able to find them? Do you care if you have to sacrifice 10-25lbs of meat? Some people do. An FMJ through the heart/lungs will get the job done no question, but it'll potentially be slow. A solid copper pointed non expanding projectile will out penetrate anything, but it's not ideal for instantaneous killing because it doesn't transfer energy well. I.e. clearly a 50 cal solid is more emphatic than a .223 solid shot placement being equal.

 

[Wedgy]

I can speak on the 6.5mm 127 grain LRX from a 6.5x284 at 3,018 fps logging over 30 kills for pigs, deer, and 2 cow elk I never recovered a bullet and never got a blood trail. All animal died from hits to the vitals but did not bleed externally, exit holes not much bigger than bullets diameter. Cows were hit diagonally one rear ribs exiting opposite shoulder, the other entered front shoulder and exited opposite side rear ribs. So yes, they really do penetrate but not sure if they expand. I quit using the 6.5 127.
I have a dozen or so 30-06 .30 cal 165 TTSX recovered from deer and pigs in the perfect mushroom you see in the ads with ~100% weight retention. I would think the heavier .30 cal would penetrate more than the 6.5 but that has not been my experience the these two bullets.