"Inherent accuracy"...

[MAX]

Let me say this differently. Show me the science that supports the contention, then I'll believe. That Lapua makes brass for the .222 and PPC does not insure the same quality. Indeed, Lapua has a vested interest in maintaining the very highest standard for the PPC brass. Find me somebody that has done the research on combustion dynamics that support the 'short fat' theory in regards to accuracy.

How about this: "Cartridges with flash holes smaller than normal for the primer are more accurate." Right or wrong? Prove it.

 

[BountyHunter]

Max

Think about 10-15 years of BR matches have proven it without any doubt, just go to BR central and ask the question. There are some boys there that will quote data until you cannot take it anymore. 222 was king and the PPC has knocked it off. Lou Palmisano (one third of the trio that came up with the PPC) published his data and articles years ago.

You cannot really think that Lapua has different quality standards on the ppc brass over other calibers.

Almost every really competitive cartridge in LR BR today is based on the short fat 30-40 degree shoulders (6 BR, 6.5-284, 300 wsm, 7wsm, 300 AI, 30 BooBoo etc). Look at the new 6.5 Grendel for the rat guns (AR15). Look at the cartridges David Tubb has designed, tested and used 6XC for across the course shooting.

Now no one has to believe that at all. Everyone is welcome to take their money and time and do what they like and have fun. However, top competitors do not waste money or time on losing theories.

Shoot what you like and have fun.

BH

[ 03-26-2004: Message edited by: BountyHunter ]

 

[MAX]

BH, tell you what I'll do. I'll trot right over to BR Central and see if someone there can show me the documentation. Last time I visited the place it seemed mostly like a 4 alarm food fight, but I'll give it a shot. I hear what you're saying, I respect your opinion but I don't share it.

I do not own a .222 or any of the PPC cartridges, and only mentioned the .222 in reference to the quote attributed to Doug Shilen. I have no particular loyalty to any cartridge, though I have a few favorite rifles. In any case, this warm fuzzy thing we are talking about is relative. What would you call "inherently accurate" at 1500 yards or so?

If I should find the "proof" rather than the gab, I'll trot right back over here and fill you in.

 

[Michael Eichele]

Anybody can say what they want, but there is more to accuracy than just turning a bullet down a barrel. There is a reason the military went from the 30-06 to the 308 despite the 30-06 having more "punch" than the smaller 308 win. It may be true that with good components and good workmanship just about any cartridge can be made to shoot well and most shurely well enough for most hunting tasks. Some will do better than others in some circumstances. When was the last time you saw a .270 or 30-06 on the bench at the national BR competition?? Some are more "inherently" more accurate than others.

 

[Jake in NC]

.. This is not the original article nor anything "scientific" but it's what I found with a quick search..
<BLOCKQUOTE><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><HR> 22 PPC

Designed in the mid-1970s by Dr Lou Palmisano, a vascular surgeon whose interest in internal ballistics and passion for accuracy gave us the first real proof that there was such a thing as "inherent accuracy" of a cartridge itself. Working with the good doctor was Ferris Pindell, an equally accomplished benchrest shooter and gunsmith, and the other "P" in PPC (Pindell-Palmisano Cartridge).

Palmisano believed that a short squat powder column burns more efficiently, more uniformly and produces less muzzle turbulence. The claim of superior accuracy for his .220 Russian based cartridge was proved conclusively when over the course of a few short years, the .22 and 6mm PPC literally rewrote the benchrest record books

As for the claim of increased efficiency, one has only to check reloading data to see that PPC cartridges do indeed produce higher velocities with less powder.

Though it has taken an inordinately long time for the squat powder column theory to carry over to hunting cartridges, it finally did in 1998 when John Lazzeroni introduced an entire line of cartridges based on drastically shortened versions of the .404 Jeffery and .416 Rigby cases.

Unless I miss my guess, we 11 be seeing further evidence of the PPC influence in cartridges to be introduced by some of our largest firearms and ammo manufacturers -- and soon.
<HR></BLOCKQUOTE>

.. I seem to remember seeing an article about this by the good doctors but I haven't located it yet..
..As far as I know this info is good to only 300 yards.

FWIW.. d:^) JiNC

[ 03-27-2004: Message edited by: Jake in NC ]

 

[Guest]

I think you guys are looking past the obvious.
While it may be true that some cartridges are more accurate than others.. WHY?
Ever lean towards the guy who builds it.. reguardless of who "he" is.. if the rifle is built right ANY cartridge can be accurate. OR... just maybe some are easier to build for...???

I know some are thinking that well the big 30's have been winning at 1K comps and now the 6.5's are winning, and the PPC's etc. won for years in SR BR... yep you're right but why... maybe, again, some are just easier to build a rifle for...
There are A LOT of factors that go into building a great shooting rifle.. in the same respect there are A LOT of things that make inaccuracy possible. If you can eliminate these factors while building a rifle or eliminate these factors by some characteristics of different case designs, bullet tendencies, actions specifications.. then you can build an accurate rifle...

so.. let's say you pick X cartridge.. and your smith knows that X cartridge shooting Y bullet tends to give Z characteristics of performance ( encompasing pressure, recoil, etc. ) then your smith can say well I need to take this into consideration to build the rifle "this" way...
I believe that the PPC or proven BR calibers and cartridges are some of the ones that are just easier to build for.. not because there design make them more accurate in ballistics terms...

 

[Blaine Fields]

For those looking for evidence that cartridge design can actually have an effect on accuracy, just take a look at the history of 600 yd. rifle competitions. Does anyone doubt that in the '60s the 30-06, which had been the reigning champion for 600 yd. shooting, was moved to an also-ran position by the introduction of the .308 Win? When shooters began to use the .308 Win., the 600 yd. bulleye had to be reduced in size because that cartridge was so much more accurate than the 30-06. There are years of data to show that the .308 is superior to the 30-06 accuracy-wise.

The PPC experience seems to bolster the idea that "short and fat" has a design advantage over "slim and long." But whatever the reason for the effect, it is hardly debateable that cartridge design has an observable impact upon the potential accuracy of the cartridge. The .308 is a better, more accurate cartridge than the 30-06. The legions of competitive shooters are the proof. If the 30-06 could out-shoot the .308, competition shooters would be using it in droves, but they aren't.

 

[Brent]

Blain,
If so, is it less powder burned, or a shorter fatter design?

Seems less powder with the 308 is all, but...

Changing only "one" variable at a time to test each of these would take more than I think most have contemplated. Can you control ALL things to even test one variable at a time in cases designs or anything else... I think all a guy can ever do is reduce the number of variables.

 

[308 nate]

Hello,
I decided I'd stick my neck out and post my view.
O.k. lets say that all cases are perfect in their dimensions and all rifles are perfect. I would have to say I believe case construction does play a role in accuracy.For instance a .30-06 case has appox. .032 of side taper and a 17 degree shoulder and is 2.109 in lenghth to base of the neck.Now when your primer is ignigted behind all the powder in the case, it actually shoves the bullet and the unburnt powder into the barrel as it is burning the powder. More so in the .30-06 due to a funnel effect and lenghth verses width. as compared to a .300 WSM with .017 side taper, 35 degree shoulder and 1.805 in lenghth from base to neck.The more you disturb the powder before it is all burnt the more inconsistencies you will have.in theory My idea of an inherently accurate case would be to make a case that would be as long as it is wide and completly round in the combustion chamber and to have a riser from your primer pocket to the center of the combustion chamber so that it would ignite the powder in the center of the chamber and burn out evenly in all directions.Thus I would say that to an extent yes, there are more inherently accurate cases then others in comparison.
In comparison I would say the .308 is more inherently accurate then the .30-06 and the 6ppc is more inherently accurate then the .222 and the 6br is more inherently then the .243. and so on and so forth.In my mind shorter and fater and a sharper shouldered case makes a more inherently accurate case.
these are just my views.And I appologize for my lack of ability to explain my ideas.
308nate

 

[MAX]

Ric, I alluded to that in my first post on this thread.

Now for my oral report, Chapter 1:

Went to BRC, got a reply wherein a fellow listed a whole long list of things to read, 3 of which I happen to have at home. BTW, I stepped right into the middle of a thread on this subject, and...JMO but I didn't take it that those fellas put a lot of stock in the idea. Of course, that's just subjective evaluation of a subjective discussion.

First three references suggested that are available:

Designing and Forming Custom Cartridges by Ken Howell. Couldn't find one reference to the subject of which we speak.

Rifle Accuracy Facts by Harold Vaughn. Again, the term was not used although there is discussion in regards the benefits of small cartridges as I mentioned previously.

The Ultimate in Rifle Accuracy by Glenn Newick. Now I don't know Glenn from Gatorade, but he is a successful Benchrest competitor and is all over the 6mm PPC. He apparently knows the P-P fellows and has a bit of literary talent. I'm not going to quote him specifically, but in essence: The case design does NOT in and of itself create accuracy. It is the blend of capacity, flash hole size, bullet weight and quality, and powder burn characteristics; these matched with proper chamber cuts, leades and loads, brass quality...and a half dozen other issues, that create the accuracy.

This is nothing more than what is required to make any cartridge shoot well. This entire subject needs to be taken in context of application. Short range bench shooters that use this class of cartridge are dealing with the most benign of environments. Flight time is short, wind effect minimal, and target resolution is very high. Typically, flat base bullets of 60-70 grains(6mm) are used, and in the application, yes the PPC is accurate when mated with an accurate rifle and effective shooter. It is a VERY narrow application. The SR/BR class cartridges are essentially useless beyond 300 yards or so.

This is not the case with longer range disciplines. Everything else has to get involved, and the "inherent accuracy" of your cartridge is the least of all concerns. Briefly aside, Blaine mentioned the evolution of competition regarding the 06/.308, and its true. Then again, it is a structured environment that negates benefit that accrues to the 06 as the distance is not too long. And the brass was bountiful, the service rifles of the day used the same round, etc. etc. Is the.308 the darling of the 1000 yard line? When/Where does it's inherent accuracy vanish?

Well, it's off to cyberspace once again, searching for real data. Proof to me on the subject does not mean that most people use it and shoot bug holes a lot of the time, and swear by it, cross their heart and so forth. I search for technical reports, substantiated research based on sound physical principals. Dreary old or new tech reports. I'd really like to read some of Dr. Palmisano's work. He was either a devoted surgeon or ballistician. I want to know which was his passion.

Hey, one of the P's was a heart surgeon, the other a gunsmith. They didn't do bad for their dabbling. I'll be back.

 

[Guest]

MAX,

Yup, gotta agree with what you are saying...

Nate,

Not picking on you.. in your opinion you have the belief that short fat is the way to go.. I am not dissagreeing with you because in my belief you are partially correct.. but you say that you would want ALL the powder burnt in the case.. I have to dissagree with that.. I think that may lead to a host of other problems in ation constuction and the characteristics of the numerous that are avaialable.

The 308 can be more accurate than the 30-06 but WHY? is it the case design only? I don't think completely... Maybe a shorter action has somthing to do with it?

SR BR rifles are built for 1-200 yards the bullets they shoot as Max said are usless after 300 yards.. matter of fact you charge weight can vary as much as .3 grs and not affect bullet POI, this has been proven numerous times...

as I said there are many more variables that come into play when you talk of why a cartridge is accurate.. it is NOT only the case design but the design as well as the constution of the action, the trueing of the action, lugs, etc... even how the barrel is attached to the reciever...

 

[MachV]

proper amount of input
Great statement and might just be the bottom line to the question.
Lets beat STL with his example for a minute(or two

.He suggests that the 50bmg is a walk in the park to get good groups out of.He however didnt go into this quite as haphasard as he would have a rookie believe.First off he is a diciplined shooter properly trained in good form and the Wolf has conditioned him a little for the recoil.He chose a good gun with a great brake,then put good rings on it with a great scope!He then reloaded 750Amaxes(measured for length to the millionth

and H50BMG(again proven performers).I doubt too that he gives his walking encyclopedia and calculator of a spotter enough credit

.I wonder too if his results would have ben the same 5 years ago?
Inherently accurate or inaccurate?Yes its a factor but definatly not the biggest factor as there is no substitute for proper settup,trigger time and correct translation of the results.

 

[Blaine Fields]

Brent, I don't know the answer as to the whys. But what I do postulate is that people who ocmpete will gravitate to the most accurate setup possible. The fact that scores shot up with the introduction of the .308 and ultimately the bullseye had to be reduced in size means to me that competitors were shooting better (actually much better) with the .308 than with the 30-06. Given the huge number of different people, different rifles, and different equipment with the only commonality being the cartridge, I conclude that the interior ballistics of the .308 are superior to the 30-06. Exactly why, I can't say.

It will be interesting to watch what happens to the 300 WM now that the 300 WSM has arrived. If "short and fat" is the reason for superior interior ballistics, then we should see the WSM line of cartridges outperform their slimmer cousins in terms of accuracy in a wide variety of applications and over a sufficient period of time.

 

[MAX]

Just reviewing NBRSA records: 5 shot groups @ 100,200,300 yards. Most were made before the PPC cartridges gained fame, only 3 out of 12 as I recall shot in the 90's or later. Few in the 80's, rest in the '70's. Hmmmm. It appears that there is more interest in agg. scoring now...or something. Most dates on agg. score records are fairly recent.

Short cases may offer some benefit in regards to ignition in that the powder column is shorter. It compounds the problem of stuffing enough propellant in the case to get the job done. When your chamber is wider than it is long, you might want to try another hobby.