Best Cartridge Designs?

[ebb]

I've seen numerous references on forums about well designed cases. I know that different uses will require different calibers, case capacities and different shapes. What are the design features that are desired in an accurate match rifle case? I like the idea that some shoulder angles will almost prevent a case from growing, but do they have a down side?

 

[K22]

Technically, I am not knowledgeable enough to intelligently answer your question, but I will say, in my day, the 222 Rem was considered the perfectly designed case for benchrest level accuracy.

I believe history substantiates the success that this cartridge achieved and if you have ever owned one as I had, you quickly understand the outstanding accuracy potential of this fantastic little cartridge.

 

[C.E.Smith043]

Long neck, step shoulder, short fat body

 

[LHSmith]

The sharper the shoulder the more feeding issues come into play.

 

[Fuj]

Trend over the years has been shorter cases, to work with the
much faster powders.

 

[FNSafari]

.308 Norma Mag....just right case capacity, neck a bit longer than one caliber, fits 30-06 length action, very efficient. However 300 Win Mag eclipsed it in short order for a lot of non-performance reasons. Read Ken Waters articles about the case in the Pet Loads book. If you don't have it and shoot a lot you should.

Ken Water's Pet Loads Complete Volume

SLIGHTLY DAMAGED. Ken Waters PET LOADS Complete Volume. This is Ken's monumental lifetime work in the handloading field andcontains loading procedures, tables, tips, precautions and commentary; over 150 cartridgesare detailed. No handloader's library is complete without this comprehensive book...

www.wolfeoutdoorsports.com

 

[dantiff2]

Look at the 6 XC. That is perfection! Imagine if Hornady had control of the marketing : ) There would be no better cartridge design in history!

 

[mike a]

i think with really good barrels, bullets and load development just about any cartridge can be accurate. I do like 6BR though. Cheers Mike

 

[NZ_Fclass]

It's an interesting thread. There's good reasons why the 30-06 and later the 308 had the shapes that they do. The cartridge was designed for function. It needed to feed in military rifles - later semi-autos and performed it's duties well.
Earlier cartridges - say the .577 also performed an ergonomic need to load in single shots and the rim was ideal and followed the form of a shot shell.
Now we are looking at a new generation of cartridges with good design characteristics - the Creedmoor, PRC, ARC are all designed with newer thinking. Increased free bore Hornady calls it "headroom" -, faster twists to accomodate long for weight bullets, getting away from the silly "belted" magnums ( never understood, along with ventilated ribs on rifles) smaller, efficient, powder capacities and arguably, better manufactured brass etc.

There has always been spill over to the manufacturers from the wildcat cartridges. What they are doing now, was done over the last few years by many members of this forum. I had my first "fast twist" 223 built around the time that 69g bullets became available and still have it - a BSA Hunter with a Pac-Nor barrel.

So what looks good? I'm a fan of the Creedmoor, the Dasher and the SLR wildcat (I have 2). I suspect the 7-6.5 PRCW will rule F-Open for a while and the other cutie is the 300 BLK.

 

[Dave M.]

7-6.5 PRCW’s definitely don’t rule F open class. In fact, I’ve only seen one 6.5 PRCW in competition in the last two years.

 

[Dave M.]

Depends what distance. If 600 yards, tough to beat the 6 Dasher or 6XC
For 1000 yards, 284 or 284 Shehane are solid competitors

 

[David Christian]

7-6.5 PRCW’s definitely don’t rule F open class. In fact, I’ve only seen one 6.5 PRCW in competition in the last two years.

Take a closer look at the big matches. Might be surprised by how many prcw’s are at the top.

 

[ebb]

What works in some styles of competition doesn't in others. ELR guys are not going to want a PPC case and point blank BR won't need a Lap Mag sized cartridge. I like the idea that a case can be shaped so the OAL doesn't grow or grow much but it brings feeding issues. So where is the compromise???? I know one size does not fit all, but it would seem some standards.

 

[NZ_Fclass]

7-6.5 PRCW’s definitely don’t rule F open class. In fact, I’ve only seen one 6.5 PRCW in competition in the last two years.

Give it time. It has only just won the World Champs. And there's no SAUM brass.

 

[DaveTooley]

OK my perfect case design. .010" taper per inch on the body, 30 degree shoulder- all to facilitate FL sizing. Neck length one caliber+. You fill in the capacity required to shoot the bullet of choice at the velocity you want. That formula has worked for almost 30 years.

Remember rule #1 in my shop is "Don't do anything to make the phone ring".

 

[Forpest]

Long neck, step shoulder, short fat body

I resemble that remark!

 

[Forpest]

Goal is accurate match rifle. But what match? What range? Short neat applies to bench rest, short range with weight limits. F-class has different rules, much longer range where wind plays a role. velocity, ballistic coefficient and consistency play a role.

 

[F Class John]

Give it time. It has only just won the World Champs. And there's no SAUM brass.

Agreed. In F Class, 7PRCW (6.5prc/7mm) also won the South African Nationals, Texas State Championship as well as the Southwest Nationals this year. It also took at least 2 of the top 5 spots at the European Championship this year.

To paraphrase (sorry Alex I can't find your exact quote) @Alex Wheeler, the 7prcw wasn't made to be a magnum cartridge, it was made to be a more stable and longer lifed 284 shehane to which it's done admirably. Brass life is insanely long, barrel life has been great for most using it and tuning is largely easy with a number of powders. It has huge flexibility. I've seen it hammer in the 2700's, 2800's, 2900's and surprisingly I've even seen a few hitting the 3,000's with accuracy although brass life will probably suffer.

 

[whatwind?]

i need a cartridge to read the wind for me

 

[dcali]

I'm of the (mostly unfounded) opinion that case design is mostly about capacity, and that certain features contribute to quality of life, utility, and brass life. You can make just about any common case shoot really well if it's the right size for the bullet/barrel you're using. A good sharp (30ish degrees) shoulder and relatively straight taper with a long enough neck to avoid the donut are all positive features in my book.

What I don't believe (again, anecdotal) is that within reason the case geometry impacts ignition or barrel life. I would happily be proven wrong on that, but it just doesn't seem to matter.