Lamar--I don't know what they are called, but did you put one of those special air cleaners on to boost power and gas mileage?

Lamar--cold air induction is the name I was trying to remember. Did you install one?

Great synopsis on ole larry's methods Lamar. I loved it. Too bad it wasn't said years ago.

Anyone loading cast for the 6.5 Swede don't believe any of the BS you read on the internet especially from the big guru over on the Castboolits forum. I'm going to tell you once: If you are getting oblong bullet holes in your target it IS NOT FROM HIGH RPM WITH FAST RIFLING TWISTS. If your bullets don't have any flaws, that is internal voids and such, to unbalance it, and the noses aren't damaged....THEY HAVE TO ENTER THE BORE STRAIGHT!!!!!! If they don't accuracy will go out the window and you will probably get oblong holes in the target. If the RPM has nothing to act upon on the bullet it does nothing to destroy the accuracy of the bullet. With the Swede it is imperative that you have a fat cast bullet say in the neighborhood of .268, but this depends on the individual rifle. The best cast bullet I've seen for the Swede is the 6.5 Kurtz designed by 45 2.1 and the mold made originally by BaBore, but now Mihec molds makes it I believe. It's a Loverin style bullet, but doesn't have the crappy narrow bands the Lyman Loverins have. I've pushed this bullet made of 50/50 alloy (WW's & Lead) to nearly 2400 fps in the Swede. That's way over and far beyond the big guru on the Castboolits forum says can be done. He couldn't and can't do it. Those same guys over there will also tell you that the supposedly long looking Cruise Missile (it's actually not longer then the Swede's original heavy jacketed bullet) will cut oblong holes at 100 yards. Yup, I'll bet it does because for one thing they don't know how to load it and you have push it a little fast. It's been shot over 100 yards and the holes are perfectly round then.

Remember, and I'm repeating myself and said I would say it twice, you have to start the proper bullet straight into the bore.

cold air system, deleted the butterfly plates, and added a new [factory] intake manifold,
then I done a pulley under drive, re-flashed the computer, and added a flow matched set of injectors [also factory] then raised the transmissions line pressure 10 psi.
it is all set up for a belt driven pro-charger.

the exhaust was straightened out and moved away from the transmission in the 'underneath the car' part of the process.

More worse? Really???

quote:

Originally posted by packrattusnongratus:
More worse? Really???

Don't understand??? Possibly a picture?

Dan Lynch from Mountain Molds has an interesting article in the latest CBA Fouling Shot Journal that touches on the RPM theory. Good article if you have a chance to read it.

seein as how Dan lived like 15 miles away from me up until about 5 years back I'm pretty familiar with his take on the matter.

I'm also familiar with him exceeding it by about 300%.

Thats interesting Lamar, doesn't seem to be the message he's sending in the article he wrote.

quote:

Originally posted by zrp:
Thats interesting Lamar, doesn't seem to be the message he's sending in the article he wrote.

After I read it I'll elaborate, but I can tell you that accuracy has been achieved with cast bullets having a very high rpm by many. The ones professing it can't are the ones that don't know how to do it.

Can I assume that most of us has Veral Smith's book? I've been buying his lube as well for years + even from his wife when he was (working for the government as they say.) I hope my small purchases helped to suppliment the grocery bill.

I think the issue has sort of been explained above even though the personal animus largely covers it up. Cast bullets and jacketed bullets are the same in this regard. If you have voids on occlusion in the bullet; the faster you spin it the wobbly-Er it gets. If you have perfect or nearly perfect bullets, rpm has little effect on accuracy or terminal effect. The trick with cast is creating the perfect bullets. And fit to barrel etc.
if one was making crappy Ill fitting jacketed bullets at home, spinning them very fast, you would have crappy targets as well.
I love my cast hunting loads but I don’t make my rifle bullets. I buy them. I’ve cast lots of pistol bullets. I have some rifle moulds on hand for just in case.

quote:

Originally posted by Fury01:
I think the issue has sort of been explained above even though the personal animus largely covers it up. Cast bullets and jacketed bullets are the same in this regard. If you have voids on occlusion in the bullet; the faster you spin it the wobbly-Er it gets. If you have perfect or nearly perfect bullets, rpm has little effect on accuracy or terminal effect. The trick with cast is creating the perfect bullets. And fit to barrel etc.
if one was making crappy Ill fitting jacketed bullets at home, spinning them very fast, you would have crappy targets as well.
I love my cast hunting loads but I don’t make my rifle bullets. I buy them. I’ve cast lots of pistol bullets. I have some rifle moulds on hand for just in case.

You said: If you have perfect or nearly perfect bullets, rpm has little effect on accuracy or terminal effect.

Now we're talking. That sir is a very hard thing for most to do is cast a perfect or near perfect bullet. The naysayers are the one's that can't.
If you have more then .1 to .3 weight variation between bullets you're not casting right. I saw the fore mentioned guru of rpm casting and weight figures and although he thought he was casting (in his words) excellent bullet he was not. Then your battle has only just begun. First off it has to be a good bullet design. Then the hardest part getting it started straight into the bore.

quote:

Originally posted by NormanConquest:
Can I assume that most of us has Veral Smith's book? I've been buying his lube as well for years + even from his wife when he was (working for the government as they say.) I hope my small purchases helped to suppliment the grocery bill.

Well then you should know that Veral depises "theory" on anything!!

Vzerone---You have mentioned getting it straight into the bore. You have lost me totally on that one. I have several questions. How do you make sure it's straight? How can you tell it's not straight? Once in the chamber, how can it be anything other than the position it's in? I'm missing something on this one.

quote:

Originally posted by carpetman1:
Vzerone---You have mentioned getting it straight into the bore. You have lost me totally on that one. I have several questions. How do you make sure it's straight? How can you tell it's not straight? Once in the chamber, how can it be anything other than the position it's in? I'm missing something on this one.

Carpetman1 there is much to that. More then making sure the cartridge's centerline is inline with the bore's centerline. Just a few things for the cartridge end of it: Make sure your cartridge fits the chamber as closely as practical. Some people do that by neck sizing only. That's okay if your chamber is straight and your sizing dies is straight. Also you use the thickest case necks that still will let the cartridge chamber. That one is hard because for many cartridges you can't always get thicker necks. What you want is a neck that is real thick that you neck turn it down to the exact fit you are looking for. I want to add you can have a custom chamber reamed to achieve those results too.

back in the old days and still in the new days there are still a lot of guy's breech seating their bullets.
they do so with plain base bullets do gain the accuracy edge it affords.
many of us using 'fixed ammo' rely on what would be termed a mechanical fitment to get almost 100% lead to steel contact right from the start.
you cant crooked something being held straight in the centerline of the barrels center by the case, the ball seat area, the throat taper, and any small part of the nose that rides the lands.

you can screw it all up by buying a rifle with a chamber that is off-set from the center of the bore, or cut at an angle to the bore/groove.
that right there is a no win situation with any type of bullet made no matter how good it is.

now you can have a well cut chamber in line with the barrels centerline and still screw yourself over with poor case fitment.
using a long bore ride bullet or one that isn't suited for alloy movement [noo matter how hard you make it] or having a poor design not suited to taking up the lead moved by the engraving of the lands.

quote:

Originally posted by zrp:
Dan Lynch from Mountain Molds has an interesting article in the latest CBA Fouling Shot Journal that touches on the RPM theory. Good article if you have a chance to read it.

Okay zrp I read it and it's full of conjectures and assumptions and doesn't give a clear cut set of directions for one to follow and shoot more accurately.

Some news on rifling twists now showing in some cases that the spinning the bullet faster is better.

Recent radar work with twist rates and projectile long-range performance have led to new understanding of projectile performance and twist rates. It's no longer good enough to say that we only care how a projectile performs from 1,800 to 3,000 fps. We now have to seriously consider how a projectile behaves at transonic and subsonic velocities. Studies with Doppleer radar have shown that, particularly for long, heavy projectiles, these bullets fly better at long distances when spun faster. As the twist rate and stability of the long, heavy Hornady 225 ELD-M projectile (for an example) increases, it's drag coefficient function gets lower, particularly in the transonic Mach numbers--below 1,200 fps. We also see that the drag curves flatten and does not climb at transonic Mach numbers. In short, the projectile is transitioning through transonic Mach umbers much better as ti is spun faster. This is why we are seeing twist rates that are faster then we have been using to seeing in the past.

So much for the RPM Guru over on Castboolets. Too you sir the reason YOUR cast bullets show less accuracy when spun faster is due to imperfect bullets, or bullets started into the bore crooked, or a host of other things, particularly things you are doing in your reloading.

You have mentioned getting it straight into the bore. You have lost me totally on that one.

you cant crooked something being held straight in the centerline of the barrels center by the case, the ball seat area, the throat taper, and any small part of the nose that rides the lands.

So much for the RPM Guru over on Castboolets. Too you sir the reason YOUR cast bullets show less accuracy when spun faster is due to imperfect bullets, or bullets started into the bore crooked, or a host of other things, particularly things you are doing in your reloading.

What you fellas are looking for and talking about is "principal axis tilt". That is the center line of the bore. If you don't get into the bore on that center line, the bullets won't go into the same hole........ and yes, there are a myriad of ways to really mess that up!

quote:

Originally posted by 45 2.1:
You have mentioned getting it straight into the bore. You have lost me totally on that one.

you cant crooked something being held straight in the centerline of the barrels center by the case, the ball seat area, the throat taper, and any small part of the nose that rides the lands.

So much for the RPM Guru over on Castboolets. Too you sir the reason YOUR cast bullets show less accuracy when spun faster is due to imperfect bullets, or bullets started into the bore crooked, or a host of other things, particularly things you are doing in your reloading.

What you fellas are looking for and talking about is "principal axis tilt". That is the center line of the bore. If you don't get into the bore on that center line, the bullets won't go into the same hole........ and yes, there are a myriad of ways to really mess that up!

Yeah and you got that "PAT" off me on the phone today you bugger!!!!!!!!!!!! I was saving that for another post.

That term is used in Ballistics, principally describing which end is in line with the trajectory path. External ballistics but used here in internal ballistics.

quote:

Originally posted by 45 2.1:
That term is used in Ballistics, principally describing which end is in line with the trajectory path. External ballistics but used here in internal ballistics.

...but you never used it in any of the forums I ever saw you on!!!! I like how you take something I mention and run with it.

I'll go ahead and explain before you do that too. Chamber design has evolved in recent years on some basic design criteria. Perhaps the biggest change in a chamber design is the throat design, sometimes called the "freebore". This is the section of the barrel immediately ahead of the chamber and is the transition to the bore. It can be a straight taper from the case mouth or a straight section followed by a taper to the bore. In the past, there seemed to be little rhyme or reason to the design of the throat. Until the last 15 year, the diameter of the throat of many chambers could run anywhere from .003-inch to .010-inch greater than the projectile diameter. The problem with this type of throat design is that it can allow the projectile to become yawed in the throat while engaging the rifling. This is called the Principle Axis Tilt, or PAT. The angle of the projectile centerline to the centerline of the bore is not controlled. It is allowed to yaw to a lesser or greater degree. When this occurs, the projectile will maintain this yaw down the barrel and at the muzzle. This is the primary cause of inaccuracy and why, for a long time, the first thing that was done in handloading to attempt to improve accuracy and control PAT was to seat the bullet in the case so that it was touching the rifling when chambered. I might add, jacketed bullets being tougher then cast bullets, can straighten themselves out a little bit from that yaw. One of the people writing about this right now and wrote this up is Dave Emary.

He might be writing about it, but he learned it from someone else. It's nothing new and has been around a long time and is quite a bit more involved than what it appears to be. Take "Dynamics" as a college engineering class, that's only an introduction to what a body in motion does and the forces acting on it.

Type "Principle Axis Tilt" into an internet search engine and see what comes up.

Just as you and everyone else learned from someone else. People need to learn by doing wherever possible, rather than simply hearing or reading about how to do. How many things have you actually invented and not learned from someone else? You went to school, and by other means, learned things. Like I said you and none of the so called experts have ever mentioned PAT in the over a decade you all have been fighting.

If you punch that into a search engine you get where it wants to call it a "principal" rather then a "principle". If you look up the meanings of both principle more applies to science. Who's right and who's wrong?

Looking the word up on the internet, I see this:
A principle is a rule, a law, a guideline, or a fact. A principal is the headmaster of a school or a person who's in charge of certain things in a company. Principal is also an adjective that means original, first, or most important.

So, it seems (as you say) that principle applies more correctly. As for learning something in school, school gives you the basics and if you don't know more than you're taught, then you basically wasted your time going. That's my take on that and there are a lot of people out there that believe that also.

That PAT as you've called it is actually called something else in engineering terms and involves more data, planar and spatial, than is indicated. What or where does the tilt occur as you've read the article.... does he explain it or not?

I think Larry Gibson's middle name is Pat. Maybe he invented this.

quote:

Originally posted by carpetman1:
I think Larry Gibson's middle name is Pat. Maybe he invented this.

Actually his middle name is Raymond!!

He not being one I idolize nor have a fixation to, wasn't sure what his middle name might be.

quote:

Originally posted by carpetman1:
I think Larry Gibson's middle name is Pat. Maybe he invented this.

He is not old enough nor does he have a scientific background considering what he has said his schooling was. There is enough problem with what he says without considering what he copies off others.

Once you make a good bullet and figure out how to launch it straight into the bore, you still will have accurate velocity limitations unless you address one more issue which is actually directly related to velocity and ROT. This particular issue does not, however, have anything whatsoever to do with "'centrifugal' force acting on 'imbalance' (sic)".

You know an advantage a jacketed bullet has over a cast bullet, one among many, is if the jacketed bullet is smooth without even a cannelure, it has less drag. Don't think for one second that all those lube grooves in cast bullets, and many copper solids, don't affect it.

quote:

You know an advantage a jacketed bullet has over a cast bullet, one among many, is if the jacketed bullet is smooth without even a cannelure, it has less drag. Don't think for one second that all those lube grooves in cast bullets, and many copper solids, don't affect it.

This would be friction. Try muzzleloading a jacketed bullet.

quote:

Originally posted by carpetman1:
Try muzzleloading a jacketed bullet.

Easily done with a sabot or by patching it large enough..... very old technology Ray.

Sabots and patched was not the topic. We are talking metal to metal.

quote:

Originally posted by carpetman1:
Sabots and patched was not the topic. We are talking metal to metal.

We are talking about the rpm threshold BULLSHIT.
That's the topic I titled.

Vzerone---Guess you were off topic. YOU made the post that jacketed bullets are smooth. I responded to that.

quote:

Originally posted by carpetman1:
Vzerone---Guess you were off topic. YOU made the post that jacketed bullets are smooth. I responded to that.

Wrong again Batcarpetman, I said IF "IF" the jacketed bullet is smooth.

Gibzerone--A jacketed bullet, spit shined to a diamond luster is going to create more friction, because it is harder, than a softer alloy bullet.