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

[Mickey D]

I am a heavy bullet for caliber/chambering fan. I do not have a dedicated coyote gun (yet), but I have plenty of deer/antelope hunts that have turned into one. The farthest I have a coyote thus far is 525Y with 175 Matrix VLD at 2996 FPS out of mine .270 AI. MPBR is 261Y at 100Y sight-in per calc in #12.
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I also have .25 cal (.257 WBY) with 1:7", but I currently load them with 145 Black Hole and 163 Chinchaga. I have 117s from two bullet makers if I want to go light, but I have since put it on the back burner, especially with the 180 Chinchaga coming soon. @Bghunter338

Good luck with your future build and coyote hunts.

I shoot Matrix 165vld out of a 270 wby. I have shot it out to 1000 yards with good results. My buddy borrowed it and shot two does in the head at 700+ yards. It is a shooter. We use a zeiss range finder.

 

[6.5x300 WBY]

Twist rate could allow a bullet to get to 1,000 yards sooner. Too little twist can lower the BC. Lower BC would cause loss of bullet speed and the bullet would arrive latter. But not by much.

Flat is all about high muzzle velocity and bullet BC. Flattest will be the bullet that gets to distance in the least amount of time.

I would think that a 7 RUM could be as flat as a 6.5-300. Both are about the same overbore so could get the velocity. It's all going to depend on the bullet BC and velocity combination. The 7 RUM shooting a 180 Hornaday ELDM with about 0.4 G7 BC should have a chance against 6.5-300 shooting the highest BC 6.5 bullets. No 6.5 bullet that I've seen approaches 0.4 BC.

Right now I have my 6.5x300 shooting 153.5 BERGERS. .356 G7 at 3300 fps at current. Still in load development. Should be impressive at distance

 

[Horse1]

Flat is all about high muzzle velocity and bullet BC. Flattest will be the bullet that gets to distance in the least amount of time.

"Flat" and "Drift" are expressions of the measurements of gravity and wind-drift of a projectile. The way to reduce both is to reduce a projectile's time of flight. Less time of flight, less time for 32'/sec/sec to pull the projectile to the earth, and less time for whatever wind there is to effect a projectile's POI vs. POA.

One must find the balance of velocity and BC that best suits their purpose for reducing TOF at their intended range of target engagement.

 

[SKanez]

I shoot Matrix 165vld out of a 270 wby. I have shot it out to 1000 yards with good results. My buddy borrowed it and shot two does in the head at 700+ yards.

Why?

 

[fseaman.js]

Twist rate could allow a bullet to get to 1,000 yards sooner. Too little twist can lower the BC. Lower BC would cause loss of bullet speed and the bullet would arrive latter. But not by much.

Flat is all about high muzzle velocity and bullet BC. Flattest will be the bullet that gets to distance in the least amount of time.

I would think that a 7 RUM could be as flat as a 6.5-300. Both are about the same overbore so could get the velocity. It's all going to depend on the bullet BC and velocity combination. The 7 RUM shooting a 180 Hornaday ELDM with about 0.4 G7 BC should have a chance against 6.5-300 shooting the highest BC 6.5 bullets. No 6.5 bullet that I've seen approaches 0.4 BC.

I agree that proper twist can "help" but not by "making", it is more "allowing". To low a twist will allow "wobble" which will slow down faster, AKA "lower BC" but it is more a case of increasing "time of flight" because of the wobble induced drag. The only way we can calculate the ballistics solution is by BC.

 

[Arken7mm]

Right now I have my 6.5x300 shooting 153.5 BERGERS. .356 G7 at 3300 fps at current. Still in load development. Should be impressive at distance

What is the twist rate on that barrel?

 

[6.5x300 WBY]

What is the twist rate on that barrel?

1-8

 

[fseaman.js]

Has anyone done any testing of the 7mm RUM with a 1:8" twist to find out? Could a 7mm RUM be flatter shooting than a 6.5-300 wby with hand loads at 500 yards and 1000 yards?

It would be nice...

Ballistics solutions calculator applications don't include twist, bullet length or stability. They assume stable bullet. Now I'm gonna look for apps that add stability and adjust solutions.

 

[RH300UM]

Has anyone done any testing of the 7mm RUM with a 1:8" twist to find out? Could a 7mm RUM be flatter shooting than a 6.5-300 wby with hand loads at 500 yards and 1000 yards?

My 7 rbh (7mm/338 nmi) pushes 195 bergers @3278 in a 8 twist barrel. The 7rum will be 50-60 fps slower in my experience with this bullet.

 

[Varmint Hunter]

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

22-243 w 30gr Berger at 5,300fps

 

[fseaman.js]

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

22-243 w 30gr Berger at 5,300fps

Do you mean Barnes?

I can't find a 30gr Berger, just Barnes and Speer.

 

[Varmint Hunter]

Do you mean Barnes?

I can't find a 30gr Berger, just Barnes and Speer.

I think they dropped the 30gr some time ago.

 

[fseaman.js]

I think they dropped the 30gr some time ago.

Okay, found it.

and

Using the same calculator that Rom Spomer used in his Videos ad Blogs, it would be flatter than the 240 Weatherby to 300 yards. 10.06 inches vs. 11.66. Unfortunately that calculator only has 1 digit precision on time of flight so it ToF looks the same as the 240 Wby but we know it's not. The 240 is solid .26 second ToF. I'd bet that 22-243 Middlestead with a 30G Berger Match Varmint at 5300 is .256, which at 300 yards is a long time.

Side note: I prefer to get the numbers from JBM Ballistics and ShooterCalculator and average them but JBM won't go over 4800fps.

 

[Calvin45]

For you obscure history buffs I present the 7.92x94 Patronen. Early attempt at hypervelocity anti tank rifle designed by Nazi germany in ww2.

Also from this era is the 7.92x107DS from Poland.

The German round is "only" 94mm case length but greater than .800" case head diameter! The Polish is 107mm case, longer than a 50 BMG and with a .645 case head, very much like a cheytac case but a full inch longer again. And necked down to 8mm.

Both these cartridges we'd think of as 8mm, .322-.324 bore diameters cited.

Both fired from rifles with barrels in the vicinity of 40+ inches, both reported to drive 225 grain tungsten cored armor piercing bullets AT OR OVER 4000 FPS.

In the end this path proved unfruitful, they were still just not powerful enough to seriously damage large heavily armored vehicles, very unwieldy, and required very frequent barrel replacement. They were even designed to be easily barrel swapped, under 300 rounds.