Can plains game A Frames or TSX bullets be 30% lighter?

[One Day...]

Hello;

In order to avoid misunderstandings, please note that we are talking about plains game expanding bullets, NOT dangerous game solid bullets.

For the sake of discussion, allow me to arbitrarily pick a few dates to illustrate expanding bullet recent history: 1) pre-1948: soft-point bullets; 2) 1948: invention of the controlled expansion Nosler Partition bullet; 3) 1969 (?): invention of the Bitterroot Bonded bullet; 4) 1984: invention of the Swift A Frame bullet; 5) 1989: invention of the Barnes X mono-metal bullet.

Basically, old soft points expanded unreliably (too much or not enough) and velocity was the primary factor in regulating expansion, weight retention and integrity. The Nosler Partition relies on a divided jacket to trap and retain the rear core and penetrate, while the front core expands, generally violently. Bitterroot, Bear Claw, Nosler, Swift, Hornady, etc. bonded bullets rely on bonding core and jacket to retain the core during expansion. The A Frame relies on both divided jacket and bonding. The Barnes X relies on mono-metal 'solid' construction to control the expansion of a hollow point. Yes, this is over-simplified, but bear with me for a minute please.

Based on personal experience and innumerable hunters' reports, recovered Nosler Partitions have often lost 30% to 40% of their weight. Bonded bullets generally loose less (shall we say 10% to 20%?). A Frames barely loose in the 5% range. TSX & TTSX barely loose 1% or 2%. Yes, this too is over-simplified, but bear with me for another minute please.

If we accept that the "classic" bullet weights (300 gr .375; 180 gr .308; etc.) were indelibly engraved in our collective hunting mind well before even the Nosler Partition existed; and if we accept - let us just focus on the Nosler Partition - that any given Nosler Partition looses at least 30% of its weight in the first inch of penetration/expansion; then it follows that only 210 gr (70% of 300 gr) of a .375 Partition slug actually does most of the penetration; 175 gr (70% of 250 gr) of a .338 Partition slug actually does most of the penetration; or 126 gr (70% of 180 gr) of a .308 Partition slug actually does most of the penetration.

The question that is of interest to me is therefore the following: would we get exactly the same results as a Partition gets, with bullets 30% lighter that retain virtually 100% of their weight during expansion (A Frame, TTSX, etc.)?

From a trajectory perspective, heavier bullets retain their momentum (speed) longer, but this advantage is offset by the fact that longer mono-metals have higher ballistic coefficients, and lighter bullets are launched faster. Any ballistic chart will confirm that the heavier Partition do not have a meaningful, if any, trajectory edge over the lighter TTSX.

From an energy perspective, heavier bullets deliver more energy, but weight is only one factor, and speed matters a lot in the energy calculation. Again, any ballistic chart will confirm that the heavier slower Partition do not have a meaningful energy edge over the lighter TTSX.

So, should the modern (A Frame, TTSX, etc.) golden standard for an expanding .375 be 210 grain, to produce the same penetration and killing results as the 'old' Kynoch 300 gr standard did? We know that a 210 gr TTSX .375 would fly faster and flatter; recoil less; hit almost as hard in terms of pure energy; and should penetrate the same since it does not loose 30%+ of its weight in the first inch or so.

I am on record for having always, for the last 40 years, shot the heaviest Partition available in any given caliber, and I have been very happy with it because the rear core almost never failed to penetrate while the front core never failed to expand. But is this reasoning obsolete in the face of the newer technologies where a bullet does not loose half of its core and still expands? Heck, everything else being constant, a reduction of 10% in ejecta weight results in a reduction of 20% in free recoil. Added velocity will add recoil, so a 20% lighter but faster bullet will not quite yield a 40% reduction in free recoil, but I will gladly take a 20% recoil reduction on anything from .338 and up... Why not...

What say you? I need to re-order 100 rounds of .340 Wby for large American and African plains game. I know these will not be 250 gr Partition anymore (like the last 100), but should they be 225 gr TTSX, 210 gr TTSX, or - dare I say? - 185 gr TTSX (after all, 70% retained off 250 gr is only 175 gr...)?

Another example would be: will a 100 gr TTSX in a 257 Wby deliver what a 120 gr Partition does (after all, 70% retained of 120 gr is only 84 gr...)?

Please explain your view, this is so much more interesting and educational when you do... I have my own view, but I am really interested in your view and experience.

Thanks
Pascal

 

[stug]

In my 7-08 I use 110 gr TTSX for the reasons you have stated.

 

[Von S.]

Velocity specific, animal & weight specific , shot distance and do you want an exit should be asked.

Velocity by far will raise foot pounds to a greater degree than weight will, but will most assuredly loose momentum:-faster than it's heavier bretheren.

 

[One Day...]

Velocity specific, animal & weight specific , shot distance and do you want an exit should be asked.

Velocity by far will raise foot pounds to a greater degree than weight will, but will most assuredly loose momentum:-faster than it's heavier bretheren.

Agreed @Von S. velocity is squared in the energy calculation formula, and weight is not. But let us set aside for a minute the weight vs. velocity trade-off in term of energy calculation because we have all experienced the fact that energy sometimes kills like lightning ... and sometimes does not.

My interest is the following: does a lighter bullet of same caliber that retains its weight while expanding, penetrate and kill as well as, or better than, a heavier bullet that sheds its weight while expanding? Obviously this can be understood as velocity/animal/distance/caliber specific (i.e. a .340 Wby will have a different effect on an Eland than a .257 Wby would), but this is not what I am trying to discuss.

Rather, does a .340 Wby 225 gr TTSX arriving at 300 yd at 2,276 fps with 2,588 ft/lbs and keeping its full weight (hence retaining longer velocity and energy) during the entire penetration, kill as well as, or better than, a 250 gr Partition arriving at 2,371 fps with 3,120 ft/lbs but loosing 30% of its weight (hence loosing precipitately velocity and energy) in the first few inches of penetration?
In other words, after a few inches of penetration the previously 250 gr Partition only weighs 175 gr, while the previously 225 gr TTSX still weighs 225 gr after a few feet of penetration, hence are we better with the 225 gr TTSX to begin with?

Obviously a 250 gr TTSX that retains its weight would do better than a 250 gr Partition that does not retain its weight, but we all know that. The point is, can we shoot a lighter TTSX that keeps its weight to produce the same effect as a heavier Partition that looses its weight?

I apologize, I am not sure that I convey effectively what I am pondering ;-(

 

[Von S.]

I'd go with the weight retention of the lighter bullet

 

[Hunting Sailor]

I don’t know, but I would really like to know, so I’ll be following this thread. sounds very interesting.

 

[One Day...]

I'd go with the weight retention of the lighter bullet

It seems logical, does not it? So maybe the days of the 300 gr .375 soft are gone to reliably plug an Eland bull without killing the cow behind it... because today's 300 gr A Frame / TSX have a decent chance of punching through...
And maybe a 120 gr A Frame .257 slug that stays at 120 gr does indeed carry the punch that we were used to deliver with a .270 160 gr Partition that shrunk 30% to 112 gr after a few inches of penetration...

 

[Nhoro]

Something to consider, does the lighter bullet expand to the same diameter as the heavier bullet ? A heavier bullet will be longer than lighter bullet(calibre and design remaining constant). That would usually mean that it will expand more'. Hollow points would have a shallower 'hollow' and a-frames would have their bracing frame closer to the point resulting in smaller diameters on expansion.

If you look into the design and find that the expansion is the same ie lighter bullets have the same hollow point dimensions, then surely retained weight will determine the penetration ?

 

[Red Leg]

I, for one, really like an exit wound (I try to let the cows get out of the way) - not enough to want to shoot a solid at everything - but an exit after causing significant internal damage. I am not lucky enough to always place a bullet exactly where I want, and an exit wound increases the likelihood of recovery dramatically- at least in my experience. On anything much larger than a march hare, I have yet to see velocity of impact, caused by bullet weight reduction within the same caliber, have any real effect on killing. Hitting is another issue where a lighter bullet can extend effective point blank range. This is most noticeable in calibers with traditionally extremely heavy for caliber loadings such as the 6.5s and 7mms.

 

[PHOENIX PHIL]

@One Day...

I think if the question were can we go lighter with high weight retaining bullets in comparison to old technology, the answer is definitely yes. Would I go 30% lighter in comparison to a Partition? Hmm, that may be a stretch. That would mean that shooting a 140gr .308 North Fork or A-Frame versus a 200gr Partition.

I say that because of the mushroom. With the North Fork / A-Frame the mushroom remains intact and with it a larger surface area to drop energy with, but this also means it has the effect of stopping sooner. With the Partition, the mushroom gives way, allowing it to penetrate further even if with a smaller wound channel.

So to think you can drop that far and still get the same penetration based solely on the momentum numbers I think isn't quite correct. But dropping down at least one weight in my opinion is easily done. So in my .308 case, going to a 180gr NF over a 200gr Partition....no brainer. I might even go to 165gr. But 150gr even with the elevated velocity, not sure I'd go that far.

 

[Edge]

Monometals change the game came compared to lead cored bullets.

Used my 30-06 with 165gr Peregrine monometals a few months ago on African Plains game in Zimbabwe. The one bullet recovered weighed 143gr, lost a petal as it smashed through the far shoulder of a heavy Kudu but was caught under the skin. Complete pass through on a waterbuck through both shoulders. Expansion was good even on the slab sided civet.

Very pleased with the monometals, taking all monometals with me again to Zimbabwe in two weeks for both the -06 and .375 H&H.

 

[Shootist43]

This is an interesting point to ponder. For the sake of discussion let me ask a question. Even though a Partition "looses" the frontal portion of the bullet "rapidly" and the back end of the bullet continues to penetrate, what happens to the "lost" portions of the bullet? Do they instantly stop (which makes no sense at all to me) or do they rather change direction, thereby increasing the volume of the wound cannel? Does the larger wound cannel have an increased chance of disrupting either larger portions of an internal organ and or additional organs not in the line of penetration? To me the old axiom of
"if it ain't broke, don't fix it" applies to this topic as well. I'll stay with the heavier bullets.

 

[Therack]

On my last safari I shot a .375 with 300 grain Barnes TSX for lion, zebra and eland. My PH suggested that I should try the 270 grain TSX, he likes them better. Shot placement is the key and a 10% reduction in bullet weight shouldn’t make a difference with a bullet retaining 98% of its original weight.

 

[Von S.]

Shooter got game!

Great question!

Those fragments create an ever widening permanent wound cavity inside the animal while transferring it's energy by weight and speed inside the animal.

If Nosler made a 900 great Ballistic Tip I'd load it in my 600 ok and shoot a cape with it without any fear at all of having to shoot again.

 

[Hogpatrol]

For plains game, just shoot Bergers and do away with all this worrying about expansion stuff. In three inches, hand grenade, walk over and get 'em.

 

[Luvthunt]

I have used the Partition for many years, first in a 7mm Rem, then a 300 Wby and then a 340 wby and then a 375HH Shot quite a few animals and believed the front of the partition aided in the killing energy of the bullet by fragmentation of the separation of the front partition. Usually the heart and lung area showed the increase hemorrhaging of these partials and the rear showed the penetration.
When I hunted Africa I still used partition in my 340 and found they did all I could ask.
I Have used A Frames and like them for DG. [NOT CATS] but as my PH commented on a Waterbuck——-“Bloody h—“- that thing kills. I was using Partitions.
I’ll stick with the Parts for all PGs and the cats.

 

[Hogpatrol]

From a trajectory perspective, heavier bullets retain their momentum (speed) longer, but this advantage is offset by the fact that longer mono-metals have higher ballistic coefficients, and lighter bullets are launched faster.

I may be misunderstanding what you are saying but have you run a ballistic chart on two bullets, one heavy and one light, with the same muzzle velocity? At the same distance downrange, the lighter one will be faster than the heavier one.

 

[Ryan]

I may be misunderstanding what you are saying but have you run a ballistic chart on two bullets, one heavy and one light, with the same muzzle velocity? At the same distance downrange, the lighter one will be faster than the heavier one.

That's not how I read it. The variable that changed is only bullet weight. So the muzzle velocity would be faster for the lighter bullet. As for ballistics, I think he means within reasonable or common shooting distance, say 300 yards or less. Really, more like 200 yards for the majority of shots taken at plains game in Africa.

 

[Ryan]

On my last safari I shot a .375 with 300 grain Barnes TSX for lion, zebra and eland. My PH suggested that I should try the 270 grain TSX, he likes them better. Shot placement is the key and a 10% reduction in bullet weight shouldn’t make a difference with a bullet retaining 98% of its original weight.

I've heard and read that more than once. Another thread on another forum compared kills with the 270 and 300 grain TSX. The 270 appeared to have caused greater trauma upon examination and the game dropped faster. Recently a PH I was talking with in South Africa who suggested that even lighter Barnes TSX and TTSX bullets in 375 caliber worked better for Cape buffalo. I think he said 250 grains and maybe even 210's. He claimed they worked as well or better than the heavier ones, usually dropping with one well placed shot. He's seen more buff dropped than I have so if I ever chase them I'll be chatting more with him to see how he still feels about all this.

 

[Red Leg]

I've heard and read that more than once. Another thread on another forum compared kills with the 270 and 300 grain TSX. The 270 appeared to have caused greater trauma upon examination and the game dropped faster. Recently a PH I was talking with in South Africa who suggested that even lighter Barnes TSX and TTSX bullets in 375 caliber worked better for Cape buffalo. I think he said 250 grains and maybe even 210's. He claimed they worked as well or better than the heavier ones, usually dropping with one well placed shot. He's seen more buff dropped than I have so if I ever chase them I'll be chatting more with him to see how he still feels about all this.

He will be in a distinct minority. All PH's I have known are 300 gr or even 350 gr .375 proponents. A 210 gr .375 would have poor sectional density and the BC of a small ashtray and 250's not much better. A bullet like a TSX in 270 gr would have a reasonable chance of performing well on buffalo and offer a bit more point-blank range in hunting PG. The 300 will drive deeper. I'll stick with it.

I am sold, that on thick skinned game - of which the cape buffalo is a prime example - killing is about penetration - not foot pounds of theoretically released energy. PG is a somewhat different issue. Though again, in my experience a wildebeest is a bit tougher to drop than say a whitetail, and that a bigger deeper hole is better than a shallower one. I would go so far as to say on African game in particular, I will always choose deeper penetration over a larger wound channel. With whatever caliber I am using, I want assurance that I can take out both lungs after driving through the shoulder structure or driving from behind the last rib in a rear angled shot. I have little confidence that dumping a lot of theoretical energy is better or even equivalent to deep penetration. Wound channel - particularly the depth of the wound channel - is most important to me when considering a bullet weight and design for a specific caliber. Those choices seems to generally follow predictive expansion, and weight retention. Foot pounds of expended energy don't figure into that calculus for me except to the extent that the energy is sufficient to cause deep penetration with an appropriately constructed bullet.

And a note about the Partition. I used it for a long time because it drove deep - regardless of what happened to the front end and how quickly. Newer designs like the A-Frame and the TSX drive deep and produce a consistently large wound channel throughout their course through an animal. There are others.