257 Roy can still spank the 6.5 Creedmoor

I decided to do a bit of math and found the old 257 can still whoop the Fadmoor!

[Linked Image]

I determined for each the odds of killing a deer at 300 yards with the following parameters:

[Linked Image]

And the result?

[Linked Image]

Creedmoor was snatched. Doing pretty good for a 70-year-old cartridge.

(the results may change if you own a laser rangefinder and are allowed to use it in season)

Love it!

What zero were you using for both cartridges?

Hit probability is beyond 100% at 300yds,with a fhuqking 223 Krunchenticker.

Hint.......................

Originally Posted by Big Stick

Hit probability is beyond 100% at 300yds,with a fhuqking 223 Krunchenticker.

Hint.......................

Originally Posted by Goosey

(the results may change if you own a laser rangefinder and are allowed to use it in season)

If I do the following:

[Linked Image]

Originally Posted by trplem

What zero were you using for both cartridges?

300 yards, +/- 20% (68% of the time).

I shoot it daily and needn't guess. Hint.

The 75 A-Max isn't going in a Krunchenticker,as I like ogives above case mouths. The 75 Hornie HPBT at 2800fps is a breeze in a 18".

Now a boltgun will happily squirt the 75 ELD at 2925fps in SAAMI guise.

Hint....................

Thank you Sir, may I have another?

Getting popcorn ready, this oughtta be good.

I've admittedly never shot a 257 Wby.

Laughing!.....................(grin)

Originally Posted by Big Stick

I've admittedly never shot a 257 Wby.

Laughing!.....................(grin)

Then, what are you waiting for?

Originally Posted by Goosey

And the result?

[Linked Image]

Where does one find a 147 ELD-X?

What is the math behind your calculations or what calculator are you using?

Yep. And the cost of factory ammo is waaay less for the Weatherby as well. And when I think of ideal light-recoiling, accurate guns and cartridges, particularly for kids and wives, I always think Weatherbys.

Yes, the 257 bee is faster shooting, thanks for the lesson haha.

I always knew the Creedmoor would never have gained popularity without the cool name

Ballistic self-gratification. No doubt it was "good" for you.

I recon that’s why you see so many .257 Bees at PRS matches....

More muzzle blast, more powder, more money, And your point is?

Goosey, serious question. Do you own or have you shot a creedmoor?

Originally Posted by Pappy348

Ballistic self-gratification. No doubt it was "good" for you.

Holy freaking apples to oranges, batman.

Goosey, put your pencil to paper on the 6.5 Creedmoor with 120's and the 257 WBY with 120's.
The "spank" turns into a mild scolding when you actually compare apples to apples.

Then, just for grins, tack on 10mph to your wind velocity.

Originally Posted by SKane

Originally Posted by Pappy348

Ballistic self-gratification. No doubt it was "good" for you.

Holy freaking apples to oranges, batman.

Goosey, put your pencil to paper on the 6.5 Creedmoor with 120's and the 257 WBY with 120's.
The "spank" turns into a mild scolding when you actually compare apples to apples.

Then, just for grins, tack on 10mph to your wind velocity.

Make it a 123 Lapua Scenar in the 6.5 Creedmoor vs any 120 in .257 Roy. That is as fair a comparison as can be made.

seattlesetters - even better.

Originally Posted by SKane

Originally Posted by Pappy348

Ballistic self-gratification. No doubt it was "good" for you.

Holy freaking apples to oranges, batman.

Goosey, put your pencil to paper on the 6.5 Creedmoor with 120's and the 257 WBY with 120's.
The "spank" turns into a mild scolding when you actually compare apples to apples.

Then, just for grins, tack on 10mph to your wind velocity.

...............................Yep! Agree!

I know I always like to compare cartridges requiring 45 grains of powder... to those requiring 70....

Yeah that was my thought. Half the powder, and then compare 120s.

Originally Posted by Dogshooter

I know I always like to compare cartridges requiring 45 grains of powder... to those requiring 70....

.........Yep!!!.........Next, let us have some ballistic comparisons between the 6.5 Creed and the 6.5/300 Wby....................LOL>>>>LOL>>>>

They are both fun to shoot. Hell on deer size game!

In the 80's, IIRC, AAgaard wrote of the X bullet doing the work of a lighter bullet. Granted the BC sucked. The attributes of BC and bullet proximity to the rifling are well known...maybe since the beginning when rifling was introduced. It has been some time anyway...

Generally, yesterday's BC could be offset by powder increases and terminal performance with bullet weight.
.
Today we have both BC attributes and bullet construction performance superior to anything in the past. Downsizing makes more sense than ever.

Not that I want to ruin anyone's fun...just saying

Methinks the OP is a better angler than comedian...

I kinda want a Roy, myself....can't explain it.

I don't think the 6.5 Manbun is giving up anything. A deer within 300 yards leaves room for a lot of cartridges to shine.

Whoa, you mean to tell me that a 257bee with 70gr of powder pushing a 80gr ttsx is going to shoot flatter out to 300yds than a 6.5 creedmoor with 42gr of powder pushing a 147gr eldm??? Whoda thunk it???

Next your probably going to tell me a 338-378bee has more power than my 22 MAGNUM????

I’d like to see the math that proves that....

So who the hell uses 300 yards as a comparison of these two cartridges? Sounds like something the MSM would do in a politcal poll.... Hell, almost any rifle is suitable to 300 yards....
Use a more realistic comparison distance and bullets and let's see where the chips fall..... I'm thinking both rifles- 120 grain pills- the 6.5 more than holds its own at much longer ranges....

Bob

Originally Posted by Goosey

I decided to do a bit of math and found the old 257 can still whoop the Fadmoor!
...
I determined for each the odds of killing a deer at 300 yards with the following parameters:
...
And the result?
[Linked Image]

Creedmoor was snatched. Doing pretty good for a 70-year-old cartridge.

(the results may change if you own a laser rangefinder and are allowed to use it in season)

I'd like to see the math that gives the 6.5 Creedmoor/ELD-X only a 57% chance of killing a deer at 300 yards with a 2/5mph wind. Hell, I've gt a better chance than that with my .45-70 and .375 Winchester lever guns and 2200fps flat nose bullets. Put an accurate Creedmoor/ELD-X combo in a competent person's hands and and the probability should be near 100%.

Originally Posted by Goosey

I decided to do a bit of math and found the old 257 can still whoop the Fadmoor!
...

I didn't realize just how badly the .257 WBY spanks a 6.5 CM until I checked ammo availability and cost and ran both through the ballistic calculator.

From an availability standpoint, Midwayusa lists 14 .257 WBY loads from $39.99 to $88.99, but only loads from $51.99 and up are in stock. The WBY 80g TTSX load goes for $88.99.

By contrast, there are 52 loads listed for the 6.5 CM with prices ranging from $12.99 to $59.99. The Hornady 143g ELD-X ammo goes for $35.99.

These loads were used for comparison, sticking closely to the OP's original choices (there is no 147g ELD-X):
.257 WBY, 80g TTSX @ 3870fps (Weatherby ammo data, 26" barrel)
6.5 CM, 143g ELD-X @ 2800fps (Hornady load data, 24" barrel)

Using 7000 feet altitude. 10mph xwind and MPBR zeros for a 6" diameter target, the .257 WBY definitely shoots flatter:

At 300 yards:
-0.53" for .257 WBY
-3.77" for 6.5 CM

At 600 yards:
-33.2" for .257 WBY
-57.5" for 6.5 CM

But what about retained velocity and energy?
At 300 yards:
2995fps/1593fpe for .257 WBY
2475fps/1945fpe for 6.5 CM

At 600 yards:
2270fps/915fpe for .257 WBY
2173fps/1499fpe for 6.5 CM

And drift?

At 300 yards:
5.7" for .257 WBY
3.6" for 6.5 CM

At 600 yards:
25.5" for .257 WBY
15.4" for 6.5 CM

Given that drop can be easily and accurately compensated for, I'll take the 6.5 CM/143g ELD-X over the .257 WBY/80g TTSX for ALL my hunting needs.
* Higher retained velocity past 700 yards.
* Higher retained energy past 80 yards.
* Less drift at all ranges.

Tell me again which cartridge/load is getting spanked?

Originally Posted by Coyote_Hunter

Originally Posted by Goosey

I decided to do a bit of math and found the old 257 can still whoop the Fadmoor!
...

By contrast, there are 52 loads listed for the 6.5 CM with prices ranging from $12.99 to $59.99. The Hornady 143g ELD-X ammo goes for $35.99.

Yeah, but how much is the lipsey's exclusive 147 ELD-X? I gotta think it'd make the Weatherby a bargain. LOL

It takes 70 grains of powder and light weight bullets to kill deer at 300 yards most effectively.....the proof is in the calculator....and the secret is in the belt

Originally Posted by Whttail_in_MT

Originally Posted by Goosey

And the result?

[Linked Image]

Where does one find a 147 ELD-X?

Ooooopsie!

Originally Posted by Goosey

Ooooopsie!

Where have I seen that word before..........

If a guy "hunts", a 2fiddy 7 flat takes the guess work out, and does a 6-5 creed dirty.......

It's your Delusion(s),feel free to convince yourself of whatever you need to hear. Obviously,your "life" is wayyyyyyyyyy shy on all facets and your Insecurities grow by the day and rightfully so. Congratulations?!?

Bless your heart for TRYING.

Might I suggest dangling one of my pics,saying something I coined or perhaps punctuate in accordance,if only to further you...from YOU.

It's the ONLY "chance" you've "got".

Hint.

Laughing!.................

7 Wby whoops them both with 120’s

Originally Posted by Big Stick

It's your Delusion(s),feel free to convince yourself of whatever you need to hear. Obviously,your "life" is wayyyyyyyyyy shy on all facets and your Insecurities grow by the day and rightfully so. Congratulations?!?

Bless your heart for TRYING.

Might I suggest dangling one of my pics,saying something I coined or perhaps punctuate in accordance,if only to further you...from YOU.

It's the ONLY "chance" you've "got".

Hint.

Laughing!.................

Pardon me having the luxury of being afforded the ability of not being forced to guess...... more " of bone at my place than yours, via 2fiddy7....... hint

Haha

Go girl!!!!

It's your Delusion(s),feel free to convince yourself of whatever you need to hear. Obviously,your "life" is wayyyyyyyyyy shy on all facets and your Insecurities grow by the day and rightfully so. Congratulations?!?

Bless your heart for TRYING.

Might I suggest dangling one of my pics,saying something I coined or perhaps punctuate in accordance,if only to further you...from YOU.

It's the ONLY "chance" you've "got".

Hint.

Laughing!.................

Originally Posted by RBO

Next your probably going to tell me a 338-378bee has more power than my 22 MAGNUM????

I’d like to see the math that proves that....

(40/7000) x 1910^2 x 0.5 ÷ 32.174 = 324 ft lbs
(250/7000) x 3060^2 x 0.5 ÷ 32.174 = 5197 ft lbs

Hm. It looks like you're right.

Originally Posted by SKane

Holy freaking apples to oranges, batman.

Goosey, put your pencil to paper on the 6.5 Creedmoor with 120's and the 257 WBY with 120's.
The "spank" turns into a mild scolding when you actually compare apples to apples.

Then, just for grins, tack on 10mph to your wind velocity.

Still beats it when estimating range.
[Linked Image]

If you don't have to estimate range it's a little different:
[Linked Image]

Originally Posted by Coyote_Hunter

What is the math behind your calculations or what calculator are you using?

Find the SDs of vertical and horizontal dispersion separately (average overshoot/undershoot with dead hold and +/- 20% zero, drift at target range with wind=2.5 mph), find probability of the vertical/horizontal values being within target height/width respectively (Py, Px) using standard normal distribution, multiply them.

Brian Litz's Applied Ballistics offers a fancy calculator which shoots 1,000 virtual rounds and accounts for all sorts of variables. However the result will be slightly different (1-2%) each time. My calculation is only for fun and rough comparative purposes.

[Linked Image]

Thankfully, I learned to estimate range pretty closely years ago, using scope reticle. Now I don't have to estimate as I carry a laser good past 1000 yards.

The .257 WBY shoots flat enough but I wouldn't choose an 80g TTSX for anything but antelope and varmints past 500 yards and wouldn't choose it for elk past 350.

I think I just heard the 6.5 PRC chuckling.

Someone should call Sierra.

Go buy a box of 6.5 CM ammo. Now go buy a box of .257 Weatherby ammo. That's what I thought....you couldn't find any at the store. They should be right next to the 5 different types of 6.5CM ammo but they weren't because nobody shoots it. What? Your local mom and pop shot have some. Excellent, you go right ahead and pay that $55/box and have a grand old time. Meanwhile I just used $55 and bought 3 more boxes of CM ammo to practice with.

Originally Posted by Goosey

I decided to do a bit of math and found the old 257 can still whoop the Fadmoor!

[Linked Image]

I determined for each the odds of killing a deer at 300 yards with the following parameters:

[Linked Image]

And the result?

[Linked Image]

Creedmoor was snatched. Doing pretty good for a 70-year-old cartridge.

(the results may change if you own a laser rangefinder and are allowed to use it in season)

Nice calculations....now actually go shoot. LMAO.

right or wrong on which cartridge you like the 25 caliber bullet is the bullet that is close`s in size to a 6.5 bullet

25 caliber is .257 6.5 caliber is .264 i like both rounds but still prefer my old Roy " 257 weather Mag."

Originally Posted by tzone

Go buy a box of 6.5 CM ammo. Now go buy a box of .257 Weatherby ammo.

Two things I don't and wouldn't do.

magnum cases will always out perform short action cases...

my 264 win mag throwing 130 grain pills at 3100 will also outperform the Creedmoor.

Recoil........?

Originally Posted by Coyote_Hunter

Originally Posted by Goosey

I decided to do a bit of math and found the old 257 can still whoop the Fadmoor!
...

I didn't realize just how badly the .257 WBY spanks a 6.5 CM until I checked ammo availability and cost and ran both through the ballistic calculator.

From an availability standpoint, Midwayusa lists 14 .257 WBY loads from $39.99 to $88.99, but only loads from $51.99 and up are in stock. The WBY 80g TTSX load goes for $88.99.

By contrast, there are 52 loads listed for the 6.5 CM with prices ranging from $12.99 to $59.99. The Hornady 143g ELD-X ammo goes for $35.99.

These loads were used for comparison, sticking closely to the OP's original choices (there is no 147g ELD-X):
.257 WBY, 80g TTSX @ 3870fps (Weatherby ammo data, 26" barrel)
6.5 CM, 143g ELD-X @ 2800fps (Hornady load data, 24" barrel)

Using 7000 feet altitude. 10mph xwind and MPBR zeros for a 6" diameter target, the .257 WBY definitely shoots flatter:

At 300 yards:
-0.53" for .257 WBY
-3.77" for 6.5 CM

At 600 yards:
-33.2" for .257 WBY
-57.5" for 6.5 CM

But what about retained velocity and energy?
At 300 yards:
2995fps/1593fpe for .257 WBY
2475fps/1945fpe for 6.5 CM

At 600 yards:
2270fps/915fpe for .257 WBY
2173fps/1499fpe for 6.5 CM

And drift?

At 300 yards:
5.7" for .257 WBY
3.6" for 6.5 CM

At 600 yards:
25.5" for .257 WBY
15.4" for 6.5 CM

Given that drop can be easily and accurately compensated for, I'll take the 6.5 CM/143g ELD-X over the .257 WBY/80g TTSX for ALL my hunting needs.
* Higher retained velocity past 700 yards.
* Higher retained energy past 80 yards.
* Less drift at all ranges.

Tell me again which cartridge/load is getting spanked?

Well done, sir.

Thanks.

The numbers don't tell the whole story, though. My .257 Roberts is my favorite rifle and became so shortly after I acquired it in 2004. With +P loads and brass it shoots 75g V-MAX at just over 3600fps. I've taken quite a few coyotes with that load. For antelope we use a 100g TTSX @ 3163fps and a 110g AB @ 3013fps. Both have been more than adequate for antelope, including my last one at around 450 yards. For elk I load it with 120g A-Frames @ 2947fps. Gentle recoil and adequate power, and the .25-06 is a bit of a step up.

Haven’t read anything passed the first post.. but what idiot wouldn’t think a 257 Weatherby wouldn’t be superior inside 300 yards?

I swear feeble minds abound

Originally Posted by Coyote_Hunter

decided to do a bit of math and found the old 257 can still whoop the Fadmoor!
..

I didn't realize just how badly the .257 WBY spanks a 6.5 CM until I checked ammo availability and cost and ran both through the ballistic calculator.

From an availability standpoint, Midwayusa lists 14 .257 WBY loads from $39.99 to $88.99, but only loads from $51.99 and up are in stock. The WBY 80g TTSX load goes for $88.99.

By contrast, there are 52 loads listed for the 6.5 CM with prices ranging from $12.99 to $59.99. The Hornady 143g ELD-X ammo goes for $35.99.

These loads were used for comparison, sticking closely to the OP's original choices (there is no 147g ELD-X):
.257 WBY, 80g TTSX @ 3870fps (Weatherby ammo data, 26" barrel)
6.5 CM, 143g ELD-X @ 2800fps (Hornady load data, 24" barrel)

Using 7000 feet altitude. 10mph xwind and MPBR zeros for a 6" diameter target, the .257 WBY definitely shoots flatter:

At 300 yards:
-0.53" for .257 WBY
-3.77" for 6.5 CM

At 600 yards:
-33.2" for .257 WBY
-57.5" for 6.5 CM

But what about retained velocity and energy?
At 300 yards:
2995fps/1593fpe for .257 WBY
2475fps/1945fpe for 6.5 CM

At 600 yards:
2270fps/915fpe for .257 WBY
2173fps/1499fpe for 6.5 CM

And drift?

At 300 yards:
5.7" for .257 WBY
3.6" for 6.5 CM

At 600 yards:
25.5" for .257 WBY
15.4" for 6.5 CM

Given that drop can be easily and accurately compensated for, I'll take the 6.5 CM/143g ELD-X over the .257 WBY/80g TTSX for ALL my hunting needs.
* Higher retained velocity past 700 yards.
* Higher retained energy past 80 yards.
* Less drift at all ranges.

Tell me again which cartridge/load is getting spanked?

Significant advantage to the CM regarding wind drift, but how does it compare to the 100TTSX or the 110AB?

Or similar .257 110gr ELD-X

My father used the book Hayes element of ordinance to design guns in the 1950s.
He taught me how to do algebra when I was in grade school.
I had my son doing some calculus when he was 6. He got through college with a minor in math by age 20. But he does not own any guns.
My cousin worked for Norma in Sweden and can do internal ballistics calculations. He owns guns.

I have built rifles in 257 Roberts, 257 Roberts Ackley, and 257 Roberts Ackley rimmed.

I am probably not going to build any 6.5 Creedmoor rifles. I have a 260 Rem reamer and that is close enough.

Originally Posted by BCSteve

Or similar .257 110gr ELD-X

Since you bring up this bullet-
I ran a side-by-side comparison on JBM of the .257 Wby. and the 110 gr. ELD-X, at a MV of 3450 fps, vs. the 6.5, and the popular 143 gr. ELD-X, at a MV of 2750 fps. Zero range is 100 yards for both cases.
Wind at 10 mph, same altitude, pressure, temp, etc. for both cases. I ran both out to 600 yards, a distance to which most hunters have no business whatsoever shooting at big game, but it's just a numbers comparison.

As you can see from the data, wind drift and remaining energy are nearly identical for both cases. The .257 has the edge in terms of remaining velocity, and a huge advantage in bullet drop.

Flame on!!!

[Linked Image]

257 Weatherby, like Porsche, there is no substitute.....

Goosey,
What's your profession? You must work in academia as a math professor. The math is all predicated upon a vacuum. Now work out the math for shooter error and recoil and include that in your equation.

Originally Posted by Coyote_Hunter

Thanks.

The numbers don't tell the whole story, though. My .257 Roberts is my favorite rifle and became so shortly after I acquired it in 2004. With +P loads and brass it shoots 75g V-MAX at just over 3600fps. I've taken quite a few coyotes with that load. For antelope we use a 100g TTSX @ 3163fps and a 110g AB @ 3013fps. Both have been more than adequate for antelope, including my last one at around 450 yards. For elk I load it with 120g A-Frames @ 2947fps. Gentle recoil and adequate power, and the .25-06 is a bit of a step up.

The Robert's answers most questions.

Originally Posted by Bighorn

Originally Posted by BCSteve

Or similar .257 110gr ELD-X

Since you bring up this bullet-
I ran a side-by-side comparison on JBM of the .257 Wby. and the 110 gr. ELD-X, at a MV of 3450 fps, vs. the 6.5, and the popular 143 gr. ELD-X, at a MV of 2750 fps. Zero range is 100 yards for both cases.
Wind at 10 mph, same altitude, pressure, temp, etc. for both cases. I ran both out to 600 yards, a distance to which most hunters have no business whatsoever shooting at big game, but it's just a numbers comparison.

As you can see from the data, wind drift and remaining energy are nearly identical for both cases. The .257 has the edge in terms of remaining velocity, and a huge advantage in bullet drop.

Flame on!!!

[Linked Image]

Soooo, comparing a bullet driven by 70gr of powder with said bullet weighing 33 grains less than the other bullet driven with 40 grains of powder and we expect a revelation?

FWIW, I'm a fan of both chamberings (owning one of each) but simply don't understand seemingly sagacious, reasoning men comparing the two like that.

A 120 in the Creedmoor. A 120 in the 257 Wby. And give them both 24" tubes while you're at it – you'll have your apples-to-apples. Yeah, a 200 fps net via 30 extra grains of powder is quite prodigious at game distances.