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

[Calvin45]

I wonder what powder they used? Things like 50BMG or modern us869 wouldn't be anywhere close to slow burning enough.

 

[Calvin45]

More photos from Wikipedia. Pic one is a German soldier with the panzerbusche 39 rifle (literally "tank hunter, 1939"), pic 2 and 3 are of the polish rifle with a soldier on a horse to show how long it is! 47 inch barrel on that one, the karabin przeciwpancerny wz. 35.

 

[K.E.C. Darkside]

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.

WINNER - WINNER - CHICKEN DINNER.

 

[Calvin45]

It's of note that rounds like those I shared about likely did inspire or at least inform the development of modern day SLAP rounds…a saboted tungsten dart out of a 50 bmg or other such gun can be driven to similar velocity without the need for a 47 inch barrel, or a barrel swap every 200-300 rounds. And this ain't a precision rifle, this is a "minute of tank" rifle haha, so the very valid concerns about accuracy when using sabots at screaming velocity aren't really a big deal here. These also aren't long range anti material rounds AT ALL….they only possess a certain magical penetration ability while they're still going at warp, inside of a quarter mile and in terms of wartime use by the Germans and Poles generally much closer than that to do any real damage to the mechanisms of a machine.

SLAP rounds make more sense! But these came first.

 

[Turpentine21]

I think I would look in either the 220 Swift, 22 CM, 22-250 range with 50 grain bullets or 243/6mm range with 58-60 grain bullets if the goal is simply to maximize PBR. This way you can keep powder consumption down to reasonable levels. 25/06 with lighter bullets works well also. Brass cost and availability would also be very important.

 

[3800fps]

I was having a conversation with a fellow member here over "flat shooting cartridges" because I've been in search of a flat shooting cartridge/bullet combination for coyotes.

I'm currently shooting a 25-06 which gives me a MPBR on a 4" target of 298yds with a 115vld. I'm switching to an 80gr barnes ttsx to see what kind of speeds I can get and hopefully stretch that MPBR a little bit more. When this barrel goes south I will probably go back with a 25-06AI or 25sherman.

I know there are some wildcats out there that could possibly be "flat-er" and a realistic choice for coyotes and would like to hear yalls opinions.

I'm not looking to neck down a 308win to 17cal or run a 110vmax in a 300rum or anything wild like that. I'd like to keep powder consumption as low as possible. Barrel life isn't a huge concern but it like to get 800 rounds out of it.

What are yalls thoughts?

Stick with the 2506 or go to 2506AI for the brass stretching issue…I like the 100gr bullets but those 80 ttsx pills leave at 3800fps from 24"bbl…on coyotes or deer there is nothing to calculate out to 300yds…also there's not a lot of trajectory data to memorize out to 500yd…past that I don't think it's ethical to be plinking at live creatures ..this applies to an 8# sporting hunting rifle.

Chassis guns and dial-up scopes and computer calcs for all that extreme range shooting…lots of 6s,6.5s,7s and 30s for those games.

 

[Varmint Hunter]

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

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

Saeed, over on AccurateReloader ran a 22-243 Middlestead with the 30gr Berger and 50gr RE15 for an amazing 5,278fps. I have never heard of anything faster out of a sporting arm.

 

[Calvin45]

Saeed, over on AccurateReloader ran a 22-243 Middlestead with the 30gr Berger and 50gr RE15 for an amazing 5,278fps. I have never heard of anything faster out of a sporting arm.

Got it. 5279 is the new goal

 

[Alex Wheeler]

6prc pushing a 105 at 3450 zero'd at 275 yards you can hold dead on to 350 and hit within 3" of aim point. Thats pretty flat. Nice predator gun. Most of the really fast stuff is with lighter bullets and is flat out to 300 ish but then drops off really fast.

 

[3800fps]

Got it. 5279 is the new goal

Maybe Federal will give us the 22 Back Country next….(a necked down 7mm with a plutonium propellant in a an unobtainium case.)

 

[Arken7mm]

6prc pushing a 105 at 3450 zero'd at 275 yards you can hold dead on to 350 and hit within 3" of aim point. Thats pretty flat. Nice predator gun. Most of the really fast stuff is with lighter bullets and is flat out to 300 ish but then drops off really fast.

How does the 6.5-300 wby hold it's flatness past 300? Or, when does the 6.5-300 wby start to drop fast?

 

[TxPhred]

375 H&H with a 200 gr Hammer Bullet?

 

[fruitnut]

How does the 6.5-300 wby hold it's flatness past 300? Or, when does the 6.5-300 wby start to drop fast?

It holds up well with bullets like the 156 Berger or another with high BC. With a light 80 grain it's a lot like the 220 swift and a 40 grain.

 

[fseaman.js]

How does the 6.5-300 wby hold it's flatness past 300? Or, when does the 6.5-300 wby start to drop fast?

Using Ron Spomer's data, for "normal" handloads or factory, the 6.5-300 is second to the 240 Weatherby at 300, #1 at 500 yards and second to the 27 Nosler at 1000.

So it retains "flatness" a long way.

Depends on bullet but it's pretty solid I haven't started the database but it will be hard to top.