SD Goals – Next Gen Ballistics Planning

[Stinky Coyote]

What do you think looks like it could be a commercial success and why?

Currently the trend is getting well above the .250 sd threshold and closer to .300 which has long been known to be related to deep penetration for heavier game. With the gold standard of one of the 20th century cartridges the 6.5x55 Swede running 160’s at .328 sd which is rarely a number matched even still today. For context a common round for Africa dangerous game is 375 H&H 300gr at .305 sd. So anything .300 or higher is getting well past most common North American cartridge/bullet combo’s.

So lets say sd goals in the .325 to .350 range would be likely for next gen offerings? Which as you can expect would bring about correspondingly high bc’s for unheard of levels of velocity retention and wind drift at distance.

Here’s some examples of what bullet weights would need to be to get into the .325-.350 ranges of sd:

.243/6mm – 134gr-145gr
.257 – 150gr-160gr
.264/6.5mm – 158gr-171gr
.277/6.8mm – 174gr-188gr (new 6.8 Western has a 175gr now which is pretty big step in this direction)
.284/7mm – 183gr-198gr
.308 – 215gr-233gr
.338 – 260gr-280gr

Of these potential future options which do you think might be a window of opportunity for commercial widespread success and why?

Personally I’d lean towards anything under 150gr to start so recoils are tolerable for majority of shooters over most disciplines.

The .243/6mm bore has a pretty major reputation in the target worlds so that could bring success on it’s own but would have to prove itself afield before wide acceptance by hunters.

.257 could be a window that be more widely accepted by hunters but would need work to win over the target crowds.

.264/6.5mm is hot right now so could still be the right diam. to go after in terms of making the jump to super duper extra high bc/sd revolutions. It could be most accepted by blends of target/hunters?

Everything above 6.5 will be hunter-centric and may not make a broad enough splash to succeed commercially for a long period of time?

Some questions we might ask, is weight of more importance than diameter? Ie; many of us have a preferred minimum weight of bullet for big game regardless of diameter…mine is 120gr. So any of these options appeal me, despite 6.5mm being a more attractive diam. to me for this reason also. I would be torn between which would be more important…the weight or the diam?

A 145gr 6mm with a .351 sd and likely a g1 bc of .75-.80 could likely be launched at 2700 fps would still hold a 2000 fps impact velocity to 700-750 yards! 500 yard 10mph wind drift would be 10-11”. With a .351 sd and 2000 fps impact…very deep penetration would be undeniable and getting to 700 yards would only take about 14 moa come up. Less than 1 rotation of a typical 15moa turret but on a newer leupold vx5-6 20 moa turret, in one rotation you get to 850 yards and since they have dual rotation turrets (cds-zl2) you get to 1300 yards in two rotations…and still have 1500 fps there, a 20 moa rail would with said leupold vx5-6’s would let you play up to about 1650 yards…and the bullet would still be supersonic to about 1900 yards.

Recoil would be about identical to a 6.5 Creedmoor running a 143/147. but in comparison to 6.5 Creedmoor 143/147’s a 145gr 6mm would add 350 yards to supersonic range and 125-175 yards 2000 fps impact distance with a far greater sd for deeper penetration and bonus of 1.5”-3” less 10mph wind drift at 500 yards.

Fun to chew on this stuff…

[huntingfamily]

It's been a long time since anyone has paid attention to SD being a meaningful measure of anything important.
It had some value when all hunting bullets were cup & core design. Now, not so much...

[Pathfinder76]

It has even less value with cup and core bullets. It has value with solids. That is it.

[Dick284]

Originally Posted by Stinky Coyote

What do you think looks like it could be a commercial success and why?

Currently the trend is getting well above the .250 sd threshold and closer to .300 which has long been known to be related to deep penetration for heavier game. With the gold standard of one of the 20th century cartridges the 6.5x55 Swede running 160’s at .328 sd which is rarely a number matched even still today. For context a common round for Africa dangerous game is 375 H&H 300gr at .305 sd. So anything .300 or higher is getting well past most common North American cartridge/bullet combo’s.

So lets say sd goals in the .325 to .350 range would be likely for next gen offerings? Which as you can expect would bring about correspondingly high bc’s for unheard of levels of velocity retention and wind drift at distance.

Here’s some examples of what bullet weights would need to be to get into the .325-.350 ranges of sd:

.243/6mm – 134gr-145gr
.257 – 150gr-160gr
.264/6.5mm – 158gr-171gr
.277/6.8mm – 174gr-188gr (new 6.8 Western has a 175gr now which is pretty big step in this direction)
.284/7mm – 183gr-198gr
.308 – 215gr-233gr
.338 – 260gr-280gr

Of these potential future options which do you think might be a window of opportunity for commercial widespread success and why?

Personally I’d lean towards anything under 150gr to start so recoils are tolerable for majority of shooters over most disciplines.

The .243/6mm bore has a pretty major reputation in the target worlds so that could bring success on it’s own but would have to prove itself afield before wide acceptance by hunters.

.257 could be a window that be more widely accepted by hunters but would need work to win over the target crowds.

.264/6.5mm is hot right now so could still be the right diam. to go after in terms of making the jump to super duper extra high bc/sd revolutions. It could be most accepted by blends of target/hunters?

Everything above 6.5 will be hunter-centric and may not make a broad enough splash to succeed commercially for a long period of time?

Some questions we might ask, is weight of more importance than diameter? Ie; many of us have a preferred minimum weight of bullet for big game regardless of diameter…mine is 120gr. So any of these options appeal me, despite 6.5mm being a more attractive diam. to me for this reason also. I would be torn between which would be more important…the weight or the diam?

A 145gr 6mm with a .351 sd and likely a g1 bc of .75-.80 could likely be launched at 2700 fps would still hold a 2000 fps impact velocity to 700-750 yards! 500 yard 10mph wind drift would be 10-11”. With a .351 sd and 2000 fps impact…very deep penetration would be undeniable and getting to 700 yards would only take about 14 moa come up. Less than 1 rotation of a typical 15moa turret but on a newer leupold vx5-6 20 moa turret, in one rotation you get to 850 yards and since they have dual rotation turrets (cds-zl2) you get to 1300 yards in two rotations…and still have 1500 fps there, a 20 moa rail would with said leupold vx5-6’s would let you play up to about 1650 yards…and the bullet would still be supersonic to about 1900 yards.

Recoil would be about identical to a 6.5 Creedmoor running a 143/147. but in comparison to 6.5 Creedmoor 143/147’s a 145gr 6mm would add 350 yards to supersonic range and 125-175 yards 2000 fps impact distance with a far greater sd for deeper penetration and bonus of 1.5”-3” less 10mph wind drift at 500 yards.

Fun to chew on this stuff…

I gonna say it again, or more precisely I’ll share this again.


https://youtu.be/N1Sw8fe9hJI


Stinky smells a little bit like one or 2 of those Mr. Harrell mentions.

[marky_mark]

Originally Posted by Dick284

I gonna say it again, or more precisely I’ll share this again.


https://youtu.be/N1Sw8fe9hJI


Stinky smells a little bit like one or 2 of those Mr. Harrell mentions.

Bingo

[1886]

That is a good utube video. Worth watching

[Stinky Coyote]

no predictions guys?

don't see any gaps or future advancements?

gives you headaches?

c'mon...you seem to be buzzing a little around the 6.8 Western....it starts into this next new world of modern in the .325 sd options that are rare as hens teeth...the 6.8 Western is definitely making a leap with extra extra heavy for cal efficiency with the 175 getting to .326 but at the energy/recoil numbers it's going to generate it will be pretty niche

just getting it on paper before people start figuring out where ballistics will be headed and then say wait a minute....that stinky c might have been onto something

when you start with that 6.8 Western 175 .326 sd and open up to .45" and still finish with with 173gr after losing tip assuming a ttsx perhaps, which would then be final .122 sd....this actually happens

if you had to guess how much deeper a 175gr ttsx (.326) may go vs a 130gr ttsx (.242) what do you figure? would about 25% deeper sound about right? like .242/.326 shows the 130gr at 74% less sd than the 100% sd of the 175gr...could be something to it

when you can go up to 25% deeper by going heavier for cal, sure does require less diam. and powder to do really effective work if you so choose (reason why the 6.5's have always performed beyond most peoples expectations)...hint, it's not because of the headstamp, it's not because of the diameter, it's not because the ft/lbs

you guys may argue that sd is irrelevant in expanding bullets, it's not, go measure one you've recovered and put the new diam. and weight into a calculator and you'll see what sd remains and you can certainly see the starting sd as well based off it's initial diam. and weight. it's a relevant number, the difference is the 'work' it did, how many inches did it travel for how many hundredths of sd lost and therefore how many ft/lbs per inch were dumped along with it...these are measurable things that we aren't measuring yet, well i am

keep telling yourself it's not the ultimate measure of penetration potential and comparison...but it is, bullet construction same(same expansion rate compared to same expansion rate) you add 25% more sd you add the same in penetration potential you go 20" or 27" deep with same construction

really want to see how it works, go same weight different construction...finished weight of a 130 ttsx may be 128gr with that .242/.09 start/stop sd....then a 130 pointed soft point that went to half inch and broke apart and finished at 80 grains...start/stop sd now .242/.046

in that example finished sd for psp/ttsx .046/.09 finished sd is 51%/100% potential...would you believe that ttsx could nearly double the penetration of that pointed soft point? do believe we've all witnessed this phenom

gets interesting when you say the psp went 11" and the ttsx went 20", they both landed with same ft/lbs....the psp just dumped it all in 11" for much greater damage over that short travel....and the ttsx dumped it all over 20" which would be much better for heavier big game? the inches hypothetical...the ratios explained are not, this is what is actually happening guys

[marky_mark]

Do you have a job? Honestly?

[Stinky Coyote]

this may not be the sandbox for sir, you can play in others, i'd have wager we have similar hours

something about a pot and kettle

[Stinky Coyote]

c'mon, there's gotta be some additional thoughts or even back to the original ask of where do you see the future in hunting ballistics headed? i provided my thoughts....what are yours?

[Salavee]

Originally Posted by Stinky Coyote

no predictions guys?

don't see any gaps or future advancements?

gives you headaches?

c'mon...you seem to be buzzing a little around the 6.8 Western....it starts into this next new world of modern in the .325 sd options that are rare as hens teeth...the 6.8 Western is definitely making a leap with extra extra heavy for cal efficiency with the 175 getting to .326 but at the energy/recoil numbers it's going to generate it will be pretty niche

just getting it on paper before people start figuring out where ballistics will be headed and then say wait a minute....that stinky c might have been onto something

when you start with that 6.8 Western 175 .326 sd and open up to .45" and still finish with with 173gr after losing tip assuming a ttsx perhaps, which would then be final .122 sd....this actually happens

if you had to guess how much deeper a 175gr ttsx (.326) may go vs a 130gr ttsx (.242) what do you figure? would about 25% deeper sound about right? like .242/.326 shows the 130gr at 74% less sd than the 100% sd of the 175gr...could be something to it

when you can go up to 25% deeper by going heavier for cal, sure does require less diam. and powder to do really effective work if you so choose (reason why the 6.5's have always performed beyond most peoples expectations)...hint, it's not because of the headstamp, it's not because of the diameter, it's not because the ft/lbs

you guys may argue that sd is irrelevant in expanding bullets, it's not, go measure one you've recovered and put the new diam. and weight into a calculator and you'll see what sd remains and you can certainly see the starting sd as well based off it's initial diam. and weight. it's a relevant number, the difference is the 'work' it did, how many inches did it travel for how many hundredths of sd lost and therefore how many ft/lbs per inch were dumped along with it...these are measurable things that we aren't measuring yet, well i am

keep telling yourself it's not the ultimate measure of penetration potential and comparison...but it is, bullet construction same(same expansion rate compared to same expansion rate) you add 25% more sd you add the same in penetration potential you go 20" or 27" deep with same construction

really want to see how it works, go same weight different construction...finished weight of a 130 ttsx may be 128gr with that .242/.09 start/stop sd....then a 130 pointed soft point that went to half inch and broke apart and finished at 80 grains...start/stop sd now .242/.046

in that example finished sd for psp/ttsx .046/.09 finished sd is 51%/100% potential...would you believe that ttsx could nearly double the penetration of that pointed soft point? do believe we've all witnessed this phenom

gets interesting when you say the psp went 11" and the ttsx went 20", they both landed with same ft/lbs....the psp just dumped it all in 11" for much greater damage over that short travel....and the ttsx dumped it all over 20" which would be much better for heavier big game? the inches hypothetical...the ratios explained are not, this is what is actually happening guys

All is good with cranking the numbers, but when it gets right down to it, just add some weight the the same caliber, same bullet and that is all you , me or most other people need. Heavier for caliber bullets equal more penetration.
Momentum is your friend if it's additional penetration you're looking for. .. not an SD number.

[Pathfinder76]

My thoughts?

Sectional density has the virility of a steer.

[Stinky Coyote]

negative (to Salavee)...sd is the number, not momentum, 6.5x54 mannlicher 159gr at 2300 fps vs 1000gr .700 Nitro Express at 2000 fps....one gets to elephant brain pan, the other doesn't...the one with all this 'momentum' doesn't

the little one has a .326 sd with 2300 fps, the big one has a .292 sd with 2000 fps, 1870 ft/lbs vs 8900 ft/lbs

that is 100 percent proof that momentum is an irrelevant number

[Stinky Coyote]

Originally Posted by chuck

My thoughts?

Sectional density has the virility of a steer.

also negative, it has the virility of the herd bull

[marky_mark]

Originally Posted by Stinky Coyote

negative (to Salavee)...sd is the number, not momentum, 6.5x54 mannlicher 159gr at 2300 fps vs 1000gr .700 Nitro Express at 2000 fps....one gets to elephant brain pan, the other doesn't...the one with all this 'momentum' doesn't

the little one has a .326 sd with 2300 fps, the big one has a .292 sd with 2000 fps, 1870 ft/lbs vs 8900 ft/lbs

that is 100 percent proof that momentum is an irrelevant number

I refer to momentum a lot more than sd

[Salavee]

[QUOTE=Stinky Coyote;4315797]negative (to Salavee)...sd is the number, not momentum, 6.5x54 mannlicher 159gr at 2300 fps vs 1000gr .700 Nitro Express at 2000 fps....one gets to elephant brain pan, the other doesn't...the one with all this 'momentum' doesn't

the little one has a .326 sd with 2300 fps, the big one has a .292 sd with 2000 fps, 1870 ft/lbs vs 8900 ft/lbs

that is 100 percent proof that momentum is an irrelevant number[/QUOTE

Well, that's the way you see it anyway. Proof ? Surely you jest ! You should read up a bit more on Bell and why he used the 6.5 if you want to keep using him and the elephants with a 12" thick skull as an example. If you don't read up, stop using him . He would be embarrassed.

[Dubious]

My thoughts, All thing being equal the skinny projectile will penetrate more that’s how defeating armour works.

[Stinky Coyote]

yes, if you mean same weight

in archery it's same thing, same bow (350 vs 450 gr arrows), everyone favors the 450 gr arrows for elk/moose and no issues with 350 gr for deer/sheep....

the 350 going way quicker, the 450 way slower but actually the 450 picks up another ft/lb or two from the bow so is more efficient but penetrate much deeper than the 350, same diam. broadheads or arrow shafts....

the sd is higher on the 450, that's why it goes deeper...it's no different if it's a spear, arrow, bullet....sd, not momentum, is the relevant factor

you must have enough velocity to overcome a given sd for game intended...back to the bell 6.5 vs 700 nitro example...2000 fps is simply not enough velocity for a .292 sd and the 6.5 with the .326 sd at 2300 does get the job done, momentum difference between them is massive but irrelevant

[Stinky Coyote]

any predictions on where the future of big game ballistics/bullets/cartridges will go? anyone?

bueller?....

[Dick284]

I ain’t gonna fall for this schtick again......
Adios Amoeba.

[Salavee]

Originally Posted by Dubious

My thoughts, All thing being equal the skinny projectile will penetrate more that’s how defeating armour works.

I agree, but I also know that a .338 dia.projectile with a skinny profile will offer much better penetration qualities on BG than a .243 dia with a skinny profile. Armour piercing bullets AFIK, were solids and had a flat nose, so we are not talking the same application. The simple fact is that most Hunters are well aware of the different penetration qualities of different bullets and they all have their favorite recipes.
In sum, all this SD crap means absolutely nothing with all the new projectiles that are available today, along with a few from yesterday. My take anyway.

[Stinky Coyote]

Originally Posted by Salavee

Well, that's the way you see it anyway. Proof ? Surely you jest ! You should read up a bit more on Bell and why he used the 6.5 if you want to keep using him and the elephants with a 12" thick skull as an example. If you don't read up, stop using him . He would be embarrassed.

Nawh....he's up there right now stackin elephants with the new 6.8 Western 175gr fmj's having a heckuva good time.

[Stinky Coyote]

crystal ball time guys....what do you see coming in the future? what's gonna be a hit? and why?

[Stinky Coyote]

Originally Posted by Dick284

Sectional Density means nothing when the bullet is changing shape as it penetrates. And no two bullets expand the same.

ttsx likely have similar expansion rates across the board, close enough to compare no?

but sd does mean something because you can measure it before, and after, and the distance in between too...you factor in the velocities which we know as well and even energy as well...you can predict much more accurately what one bullet will do compared to another

stick to the topic rather than sitting up on that tall horse...

got any predictions for what might be a future direction or hit? and why?

[Stinky Coyote]

why no challengers or contributors or thoughts on what might come next in future hunting related ballistics???? seriously, people must have some ideas where there are gaps or holes or directions the future may hold?

if not hornady better hire my azz

[Salavee]

Originally Posted by Stinky Coyote

yes, if you mean same weight

in archery it's same thing, same bow (350 vs 450 gr arrows), everyone favors the 450 gr arrows for elk/moose and no issues with 350 gr for deer/sheep....

the 350 going way quicker, the 450 way slower but actually the 450 picks up another ft/lb or two from the bow so is more efficient but penetrate much deeper than the 350, same diam. broadheads or arrow shafts....

the sd is higher on the 450, that's why it goes deeper...it's no different if it's a spear, arrow, bullet....sd, not momentum, is the relevant factor

you must have enough velocity to overcome a given sd for game intended...back to the bell 6.5 vs 700 nitro example...2000 fps is simply not enough velocity for a .292 sd and the 6.5 with the .326 sd at 2300 does get the job done, momentum difference between them is massive but irrelevant

Stinky .. I guess it doesn't matter to you anyway, but is the weight of the arrow or bullet that has the momentum potential and momentum is definetly not irrelevant.
It's been a slice, but I'm outa here. Carry on carrying on.

[Salavee]

Famous as one of the most successful ivory hunters of his time, Bell was an advocate of accurate shot placement with smaller calibre rifles, over the heavy large-bore rifles his contemporaries used for big African game.

He improved his hunting skills by the dissection and study of the skulls of elephants he shot. He perfected a technique of shooting elephants from the extremely difficult position, diagonally behind the target; this shot became known as the Bell Shot.[4]

Quote

[obsessed1]

Originally Posted by Stinky Coyote

why no challengers or contributors or thoughts on what might come next in future hunting related ballistics???? seriously, people must have some ideas where there are gaps or holes or directions the future may hold?

if not hornady better hire my azz

What does it matter what's coming next ......by the time any huge changes happen in the shooting world guns/ bullets will be outside the price range of most of us peons and JT won't trust us to be armed with anything more potent than a sling shot with 3/8 bearing......I guess we could argue 3/8 bearing vs 5/16 bearing shot out if a sling with 12" vs 14" flat strapped rubber bands lol...
I'm glad you love this stuff but reality is the new 6.8 doesn't do anything any number of other cartridges can't do...in other words....do we need the 6.8 western?......nope. But some guys will open their wallets so companies develop them.....generally speaking they won't kill anything deader than a 30-06. Or 308

[marky_mark]

How about this
Before you go flapping your yap about what everyone else has done
Why don’t you go do something yourself

Instead of telling us what you read in a book from 200 years ago
Why don’t you go to Africa and back it up
Go spend a bunch of your own money
And apply your knowledge first hand

Shooting baby mule deer and yearling moose are one thing
Go put your money where your mouth
Then maybe you might have something to talk about

I’d love to hear how your Grendel does against stompy the elephant

[catnthehat]

My old man gas a saying " quit yackin' and just shoot the dammed gun kid and put the billet where it is supposed to go"
Cat