Will,

I have been low on a couple of brain shots. Both with Woodleighs and with North Forks. They all dropped. No apparent, visible difference.

(this is why I am a fan of bigger bullets)

JPK

JPK,

Bigger is definitely better, especially when they don't drop!

I do not have the temerity to shoot elephant with anything less than a .50 cal, and they all dropped regardless of whether I hit the brain or not.

I don't mean to butt in to a good arguement but may I ask a question? I've shot a 470 exctly once and love it (considering a purchase) and have been reading Wright's book. In it he states that the old Kynoch bullets actually were caliber diameter only at the base gradually stepped down towards the nose. It makes sense taht this may be the root of the problem Taylor talks about. Wright goes on the say that current manufacturers (say Woodleigh) are bound by CIP regulations and make "full caliber" contact surface bullets (thus no taper). Would this not correct the historical problem? Sure, Woodleighs are not FN, but at least now they should be parallel sided - right?
Thanks,
lefty

I'll repeat my experience again. .470NE double, 2150fps, Bridger FP bullets 1:18 twist. Ele, Botswanna, shot 10 times( 6 while still alive), penetration through head, two side ways body pass-throughs, One sticking out of hide on opposite side. Two shots attempting to break back legs. Both hit bone, probed with cleaning rod, went in to the hilt. 4 more shots duplicated body pass-throughs. I was frankly amazed at the penetration. With modern bullets the .470NE is more than enough I'd say. Don't think I'll be loading any crappy 100 yr old Kynoch bullets in the near future, so I should not need the much coveted Over-twist protection.-Rob

quote:

Originally posted by UtahLefty:
I don't mean to butt in to a good arguement but may I ask a question? I've shot a 470 exctly once and love it (considering a purchase) and have been reading Wright's book. In it he states that the old Kynoch bullets actually were caliber diameter only at the base gradually stepped down towards the nose. It makes sense taht this may be the root of the problem Taylor talks about. Wright goes on the say that current manufacturers (say Woodleigh) are bound by CIP regulations and make "full caliber" contact surface bullets (thus no taper). Would this not correct the historical problem? Sure, Woodleighs are not FN, but at least now they should be parallel sided - right?
Thanks,
lefty

If you measure current Woodleigh solid .458, .468, or .475 bullets you will see that they taper with only that last 1/4" or so being full diameter. The taper amounts to around .002" I have never seen one that obviously turned off course or went sideways in an elephant. I have had head hit elephants not go down on initial head hits that missed the brain with the 465 and 470 but not with the Lott with 550 gr. Woodleighs. Still I feel the 470 is plenty of gun for elephants under any conditions. I have never used a flat nosed solid but may try some this coming March on eles.

465H&H

465,
it this something specific to woodleigh (trying to match old profiles) or do other brands have this property as well? Does kynamco use woodleighs or have a similar profile?
thanks

Kynamco (modern Kynoch) is loaded with Woodleigh bullets. They have a new US distributor:

www.kynochusa.com

I believe it is due to the delicate problem of designing a bullet that is hard enough to hold up to the tremendous forces associated with penetration of bone and the need to reduce barrel damage from extremely hard bullets. By reducing the area of max bore diameter, bore stress is reduced. But I may be wrong on this. I don't think the slight taper affects bullet penetration to any measurable extent but I may be wrong on that also. My 470 Searcy has made a dime sized group at 50 yds for two rights and two lefts, which indicates to me that the bullet is very stable in flight. I can't say for other brands of bullets as I haven't measured any.

465H&H

465H&H,
Are your barrels crossing at 50 yards?
That is a no-no to some around here. Be careful lest you draw the extended-pinky-finger ire!

You are safe with me. My Merkel does the same thing and I like it.

I wonder if the Buff I shot head on with my 470 using a 500 grain Woodleigh solid that lodged behind his hip was pissed because of poor penatration?

/

quote:

and the shorter a bullet is in relation to its diameter, the less likely it is to tumble."

Does that mean that monometal bullets are more likely to tumble than lead core bullets (since they are longer for equal bullet weight) all other factors being equal?

465H&H

quote:

Originally posted by ALF:
... In general, the greater the gyroscopic stability of a bullet (for example, because of a higher spin rate), the further it will go in the body before starting to tumble; and the shorter a bullet is in relation to its diameter, the less likely it is to tumble." [/color]

I read through that whole thing and found some exra good advice at the bottom of the quoted text:

Besides the right bullet shape and construction: USE MORE THAN ENOUGH TWIST on those elephant rifles.

So once again we are back to it: faster twist penetrates deeper.

quote:

Originally posted by 465H&H:

quote:

and the shorter a bullet is in relation to its diameter, the less likely it is to tumble."

Does that mean that monometal bullets are more likely to tumble than lead core bullets (since they are longer for equal bullet weight) all other factors being equal?

465H&H

If the same shape, same velocity, same twist, then the answer is yes. And that is why we see Barnes .416 400 grain X bullets and .458 500 grain X bullets tumbling so often, while lead core softs of those weights at the same velocity do not seem to encounter the same problem.

However, if the bullet is a copper flat nose, that seems to change things as more than one variable is at work.

/

Alf,
oh man, you know not to tell dan that twist doesn't do anything for penetration.. while he's never OWN or shot GAME with an overtwist barrel..

well, his mind is made up, and facts won't change his gut

jeffe

quote:

Originally posted by ALF:

No not faster twist because of in target effect of twist, faster twist because of better pre impact stability, a higher SF and thus smaller angle of attack. So in effect you have to have the most stable situation at time of impact.

Alf, I have been lecturing you on the need for faster twist to reduce yaw in order to get better penetration, but apparently you were too busy randomly quoting textbooks to listen.

/

Alf,
Read the reference you posted for help with your question.

quote:

Originally posted by ALF:
... In general, the greater the gyroscopic stability of a bullet (for example, because of a higher spin rate), the further it will go in the body before starting to tumble; and the shorter a bullet is in relation to its diameter, the less likely it is to tumble."

A few years ago, when I was independently duplicating RIP's Iron Buffalo tests with my Iron "Marlin?" bullet trap hanging off a dock into saltwater, I also did a rudimentary test of Center of Form to Center of Gravity.

The test projectiles consisted of modified factory Barnes Mono 500 grain .458RNs fired from a factory Win M70 converted to Lott (don't know twist)at 2250 fps.

One set of projectiles were modified by cutting grooves around the bore diameter section at the rear such that the balance point was shifted forward of center. These bullets were as bad or worse than unmodified bullets but I have a strong reason to believe that I did not leave enough driving surface as the single recovered slug shows little evidence rifling (see photo). Even so, it would intuitively make sense that they should have stabilized once hitting the water?

The other set of bullets were bored hollow at the base, hoping to emulate the stability of a shuttlecock. The one shot fired performed miserably in the bullet trap, no better than an unmodified slug. I did not fire any more than one slug as a standard powder charge appeared to cause significantly excessive pressure, assumed to be the result of the bullet expanding like a Minie' ball and increased bearing friction?

So my test of balance were useful in demonstrating what NOT to do with a bullet to move it's CoG forward of it's CoF. Beyond that...?

A flat nose was the single decisive factor in all my trials.



(edited to correct number of recovered slugs - only one)

quote:

No not faster twist because of in target effect of twist, faster twist because of better pre impact stability, a higher SF and thus smaller angle of attack.

Alf,

I'm not sure what twist rate has to do with angle of attack. The fuzz long ago realized that flat point bullets tend to deflect less upon impact and if that is true then a flat point bullet will inherently going to be more stable once it enters the body.

So I tend to agree with 500 grains that if the bullet is spinning fast enough to be stable in flight then the bullet shape, the flat-nosed bullet, is going to be the dominate factor once impact occurs.

This would seem to be verified by all the field reports of such large penetrations from flat-nosed bullets regardless of twist rate, such as the rather low twist rate of 470 bullets.

/

quote:

Originally posted by 500grains:
Alf, I have been lecturing you on the need for faster twist to reduce yaw in order to get better penetration, but apparently you were too busy randomly quoting textbooks to listen.

Dan,
I believe we have found the source of all of the twist issue. Dan believes he is LECTURING rather than DISCUSSING the subject. Once one begins to lecture, they have concluded it is a closed subject, and the audience is more or less passive and welcomes the information.

What scientific experience do you have that leads you to be self deluded in a position to lecture anyone on twist.

Please list the calibers, the pairs of twist(standard and overtwist, in this case, 1x10 has been your guiding start) , the bullets (shape, weight, construction), velocities, media and results you used to conduct these exhaustive tests. One understands that casual shooting into carrion can be distracting, but without direct comparisions to varying twist into the same media (carrion bull elephant or just pure bullshit) only a fool would draw a conclusion based off single sided results.


So, Dan, to affirm your position TO lecture on the matter, let's hear about your +.400 PAIR of big bores with nothing different except twist. Heck, even a takedown switchbarrel, as you were begging me to build you FOR FREE.

jeffe

wow guys take it easy, i think Fossdal is drinkin his special beer and making fine email with special attchements for all of you soon.......

The .470 is a good round and there is many hunters that has gotten a chnace to tell their story instead of anyone telling their s storys about them...

But the bullets before was good amd to day they are great, so perhaps its the parralell sides on the bullets of the .500-465 and the great .450 NE that is the difference as opposed the .470 ?

I dont know, but its a great round but its bullets could have been a little bit different designed.

quote:

Originally posted by 500grains:

...I am still getting 55 inches of penetration through ele skulls with a 505 Gibbs using 600 grain Woodleighs

Which twist? this has been asked about 20 times, and you refuse to answer. is there something you are hiding, like it's a slow twist barrel, but you that you've commited to talking about how GOOD it's penetration is?

quote:

, which are the point-style round nose as opposed to the blunt round nose.

"point style" round nose? please describe bullets in BULLET terms. You can describe by ogive, if you like, or the catch-all term "semi-spitzer." ... "point style round nose" must be a mccarthy-ism describing bullets.. no one else uses that phrase

quote:

Maybe the penetration would be even deeper if the bullet were redesigned to have a more blunt round nose, and even deeper still if redesigned as a frusto-conical projectile.

but you seem to tell us, in another thread, that twist is more important than bullet shape...

quote:

Originally posted by 500grains:
I have not experimented with twist rate versus penetration as Ron has. However, Art Alphin says that a faster twist gives deeper penetration, hence his recommendation of a 1-10 twist.

Yet, here's dan *** LECTURING ** any and all, on his profound thoughts... telling you how well the 505 gibbs penetrates, but not telling you twist of his "magic" 505.

dan, you really are schillin snakoil, aren't you?

Jeffe,

haven't you figured out yet that you will NEVER, like "when pigs fly..." get the twist answer from Dan...he has determined that that data is not germane to his postulated theory.

Here's the deal:

1. like the rest of us Dan uses traditional (read slow) twist DG rifles.
2. like a few of us Dan thinks twist rates could be speeded up.
2b. I agree with this with regard to the mono-metal solids currently in vogue; they are so
long for caliber and weight that they require a fast(er) twist to stabilize, and thus be
useable.
3. like the rest of us Dan is not stupid enough to go out and rebarrel or replace all of his
collection of slow twist rifles for the sake of a few head of dangerous game hunting each
year or every other year big game safari.
4. unlike the rest of us Dan is locked into the faster = superior penetration speculation and
will not/cannot change his position.

The continuation of this thread or any other where twist rate can be introduced is counterproductive as long as Dan is allowed to post on it. It's just a sad fact or life...
On the other hand, the babies came over yesterday for the weekend (13,10, and 7) and we got the tree bought, and set up and decorated...and had a good time at Church this morning talking about the Blessed Event 2006 years ago.

regards,

Rich
NRA Life Member
DRSS

"...God Bless us, everyone..." and that includes you Dan!

A/

quote:

Originally posted by ALF:


Assuming we have two similar shaped Solid projectiles and both impact the target with exactly the same angle of attack, same speed, the one has has a fast twist rate and the other slow, which one would go the furthest before tumbling ? and why?

Please do not assume reality out of the hypothetical.

The faster twist bullet will have less yaw, meansing a more straight on angle of incidence which will enhance penetration.

Once inside the animal, again the faster twist bullet will have less yaw, which means a lesser amount of lateral force acting on it which would tend to slow the bullet down and cause it to tumble.

And if the bullet is travelling through watery flesh (instead of bone) so that it can form a supercavitation bubble, the supercavitation bubble will be maintained longer with fast twist, again enhancing penetration.

All of this flies in the face of the simple-minded argument that "H&H used a slow twist 100 years ago, so it is good enough for me."

quote:

Originally posted by ALF:


As I have repeated over and over again and it seems to go over Dan's head.

The Gyro theorem cannot be satisfied in target because of the magnitude of mass density of the target so an ogived bullet is going to overturn, it just a question of when.

So in plain English SPIN EFFECT IS NEGATED BY THE DENSITY OF THE TARGET ONCE THE BULLET HITS THE TARGET

Alf, I understand your point, but you are not taking all factors into account, hence your conclusion, based on just one variable, is flawed. See my post above.

quote:

Originally posted by 500grains:
Please do not assume reality out of the hypothetical.

quote:

Originally posted by 500grains:
I have not experimented with twist rate versus penetration ....

Dan,
As you have stated, you do not own a fast twist .400"+ caliber, much less a standard twist and a fast twist. You have not basis, in reality or practical experience to base your conclusions on.
Please do not assume reality out of the hypothetical.

Please understand that you are only loosing ground and respect this every post you make, based off your hypothetical speculation.

When you have some experience in the matter, heck, even owning a set of medium bores with different twist, you might be able to post a factual, evidence based, reply.

So, let's put this in terms you might understand. You fail any reasonable test as an "expert witness"...

I have tried, repeatedly, to help you to find a means for you to actually test yout ideas. Short of giving you a custom takedown rifle (that you thought I should give you FREE - and then reacted poorly when I didn't just GIVE you an $8500 rifle), I have tried everythign possible.

You might review that, at this point, not even andy posts in support of your concepts.

you appear foolish, and continue to act in the same fashion after being REPEATEDLY, from several persons, informed of this.

jeffe