What is the the most flat shooting cartridge yall can think of?

[Horse1]

257x300 Weatherby. Why not ?

I know a father/son duo who built .257STW's in the late 90's.

 

[Phil Rizzo]

264WM

Trajectory
Input Data
Ballistic Coefficient:	0.620 G1	Caliber:	0.264 in
Bullet Weight:	130.0 gr
Muzzle Velocity:	3239.0 ft/s	Distance to Chronograph:	20.0 ft
Sight Height:	1.50 in	Sight Offset:	1.00 in
Zero Height:	0.00 in	Zero Offset:	0.00 in
Windage:	0.000 MOA	Elevation:	0.000 MOA
Line Of Sight Angle:	0.0 deg	Cant Angle:	0.0 deg
Wind Speed:	10.0 mph	Wind Angle:	90.0 deg
Target Speed:	10.0 mph	Target Angle:	90.0 deg
Target Height:	12.0 in
Temperature:	70.0 °F	Pressure:	29.92 in Hg
Humidity:	0 %	Altitude:	0.0 ft
Vital Zone Radius:	5.0 in
Std. Atmosphere at Altitude:	No	Pressure is Corrected:	Yes
Zero at Max. Point Blank Range:	No	Target Relative Drops:	Yes
Mark Sound Barrier Crossing:	No	Include Extra Rows:	No
Column 1 Units:	1.00 in	Column 2 Units:	1.00 MOA
Round Output to Whole Numbers:	No
Output Data
Elevation:	4.860 MOA	Windage:	0.000 MOA
Atmospheric Density:	0.07488 lb/ft³	Speed of Sound:	1128.2 ft/s
Maximum PBR:	401 yd	Maximum PBR Zero:	340 yd
Range of Maximum Height:	186 yd	Energy at Maximum PBR:	1996.8 ft•lbs
Sectional Density:	0.266 lb/in²

Range	Drop	Drop	Windage	Windage	Velocity	Mach	Energy	Time	Lead	Lead
(yd)	(in)	(MOA)	(in)	(MOA)	(ft/s)	(none)	(ft•lbs)	(s)	(in)	(MOA)
Calculated Table
0	-1.5	***	-1.0	***	3250.1	2.881	3048.6	0.000	0.0	***
50	0.6	1.2	-0.9	-1.7	3167.8	2.808	2896.1	0.047	8.2	15.7
100	1.9	1.8	-0.6	-0.5	3087.0	2.736	2750.3	0.095	16.7	15.9
150	2.2	1.4	-0.0	-0.0	3007.8	2.666	2610.9	0.144	25.3	16.1
200	1.6	0.8	0.7	0.4	2929.9	2.597	2477.6	0.194	34.2	16.3
250	-0.0	-0.0	1.7	0.7	2853.5	2.529	2350.0	0.246	43.4	16.6
300	-2.7	-0.9	3.0	1.0	2778.4	2.463	2227.8	0.300	52.7	16.8
350	-6.5	-1.8	4.5	1.2	2704.5	2.397	2110.9	0.354	62.4	17.0
400	-11.5	-2.7	6.3	1.5	2631.8	2.333	1999.0	0.411	72.3	17.3
450	-17.8	-3.8	8.3	1.8	2560.3	2.269	1891.8	0.468	82.4	17.5
500	-25.4	-4.8	10.7	2.0	2489.9	2.207	1789.3	0.528	92.9	17.7

What bullet is this using?
I like the balance of speed/weight and BC

 

[eshell]

257x300 Weatherby. Why not ?

The smoke from the burning barrel steel would choke out the shooter.

 

[Phil Rizzo]

What about a case with same capacity as a .257 wby, but .400 shorter and .037 more girth at the .200 line?
It does exist.

 

[WYO300RUM]

What about a case with same capacity as a .257 wby, but .400 shorter and .037 more girth at the .200 line?
It does exist.

A 6.5 PRC Necked down to 25 cal .?

 

[Phil Rizzo]

A 6.5 PRC Necked down to 25 cal .?

Nosler lists 6.5 PRC capacity in the low-mid 60's.
I'm talking 83-84 grs

 

[Horse1]

Nosler lists 6.5 PRC capacity in the low-mid 60's.
I'm talking 83-84 grs

25WSM?

 

[Phil Rizzo]

25WSM?

It's low-mid 70's according to Nosler
270 WSM.

The case I'm thinking of is made by ADG, only.

 

[1mechanic]

Only thing I can think of is take a 348 Winchester blow out the walls and shorten the case but it's not a high pressure case.

 

[Phil Rizzo]

More modern. By a long way

 

[1mechanic]

It's low-mid 70's according to Nosler
270 WSM.

The case I'm thinking of is made by ADG, only.

Well it doesn't seem to be listed on their website, sooo what is it?

 

[Phil Rizzo]

It's not a SAAMI stamped cartridge, like most of the greats

 

[436]

The .257 Wby Mag load that shot great through all the .257 Wby I owned was 71.5grs of H-4831 using 100gr Barnes XLC .25 cal which unfortunately they no longer manufacture, as coated bullets go it was fast and very, very accurate with velocity in the 3740 fps mark out the 26" barrels and very reasonable SDs Funny, I use the Barnes XLC 53gr .22 cal in my Wby Varmnitmaster in .224 Wby Mag, but.. this time, I bought enough to last for quite a while, and they shoot like a house-a-fire, again it's no longer made by Barnes...
As a cautionary, I should add that all the other brands of 100gr bullets I've used in my .257 Wby Mag's... the max, but safe load, was 70.0gr of H-4831 with velocities in the 3600 fps plus range. Cheers.

 

[DUCKMAN11]

What about a case with same capacity as a .257 wby, but .400 shorter and .037 more girth at the .200 line?
It does exist.

Sounds like an improved WSM