Joe your "who" assumption is spot on, but he has not jumped in yet...he has merely stuck a toe in the water. That old codger ain't gonna live forever and I would dearly like to see more of his knowledge shared before they plant his ornery old butt down the road from his house.
^that is Michigan humor^ up there...no one should take it the wrong way I owe about 85% of my HV cast success to that cagey old coot.
JOE: I/we understand the why to his method of teaching as we have been there. I would really like to see him right a book myself. He could reach the masses quicker and maybe make a few bucks writing a book.....not merely assembling one......it is not that hard to place a *caveat* in a post or on a page when the need arises.
BTW ... I want copy #1 and I want it signed.
Last edited by 357maximum; 12-30-2009 at 11:35 PM. Reason: spelling
I need a ghost writer.................... I can set you down at the bench, explain it to you, then show you how to load the cartridge correctly, then shoot a very nice group, BUT........ my writing skills along this line really suck. I write technical specs a lot, not the kind of writing skills needed here.
45 2.1
Knowledge without understanding is a dangerous thing. For a little knowledge entices us to walk its path, a bit more provides the foundation on which we take our stand, and a sufficient amount can erect a wall of knowledge around us, trapping us in our own ignorance.
Never sleep, never die
Knowledge is easy to get, but worthless if you never use it. However the info is free, so the only person you have to blame is yourself if you chose not to use the information.
One vote for Joe. Pat
Academic vs. technical writing
Subject: Academic vs. technical writing
From: Chaim Chatan <chatan -at- IDI -dot- ORG -dot- IL>
Date: Fri, 27 Mar 1998 16:29:29 +0200
Since there is a discussion of the differences between academic writing and
technical writing, let me give you the perspective of someone who has done
both. There are very important differences between academic and technical
writing. One must also realize that there are also different types of
academic writing and different types of technical writing.
First of all, the purposes and audiences are different between academic and
technical writing. The purposes of academic writing can be: 1) to present
the results of one's knowledge, 2) to present the results gained from one's
personal research, and 3) to present one's point of view. Of course, both
technical and academic writing is laden with jargon, but the jargon is used
for different purposes. As far as technical writing is concerned, the
purposes of technical writing can be: 1) to teach someone how to use a
specific product or service; and 2) to describe the procedures that are
employed by companies for carrying out various tasks.
The audiences are completely different. The academic is writing to fellow
scholars, and often, depending on the journal or publication, to the
general public. The technical writer is writing to the user of the product
or the service, or to government inspectors who need to see how the company
carries out certain tasks. Users, of course, differ from product to
product. In addition, technical writing differs from area to area. For
example, writing documentation for software is different from writing
documentation for hardware.
When I took a technical writing course as part of my professional
retraining, I had to unlearn a lot of what I had been doing as an academic
writer. We are dealing with different styles of writing altogether. Also,
there is good and bad academic and technical writing, and a good academic
writer may not become a good technical writer and vice versa. I have seen
downright awful academic writing, where the author wrote extremely unclear
and obscure prose, and I have seen extremely garbled technical writing,
where it was difficult to follow the instructions.
The important variable here is teachability. If an academic writer who
wants to become a technical writer is not teachable, especially coming from
the academic and liberal arts world, he/she will not be a good technical
writer. Good academic writing is not enough--teachability is the most
important factor. One of the most important tasks of interviewers of
candidates for technical writing jobs, especially candidates who have not
had professional experience, is not just simply to look at the writing
samples of the candidates, but to assess how teachable they are. If the
candidate has both academic and technical writing samples, the interviewer
should be able to assess whether the candidate has grasped the differences
between the two types of writing. This is one way to measure teachability.
Joe
__________________________________________________ _____________________
Actually, this thread was stickied because of the relevant discussion regarding the tools, materials, and methods used to achieve accuracy with high velocity cast boolits.
I want to be able to impress myself with MY OWN 300 yard chronograph readings, and if you're reading this thread, that should be your goal as well.
Gear
Last edited by geargnasher; 01-01-2010 at 01:42 PM.
Gear....
I've added words in red to your quote. Joe started this thread including performance in the equation by using the milk jug vs. paper for his 300 yard target.
Your second paragraph reads condescending to me. You have no idea of my knowledge or what my goals should be for that matter!
This forum is paramount in my definition as to shared experiences. Sure we can do OUR OWN testing and keep it to ourselves... or we can share it!
For your information then gear....
Joe is driving a rather soft boolit at 2300 fps. Add to that, the additional compressive longitudinal load from pushing into a very steep twist... Does Joe's 6.5 boolit take this in stride, or does it collapse some under load?
Therefore... my interest in Joe's 300 yard velocity reading is a measuring tool. Did Joe's bullet change in its coefficient of form during launch? If it collapsed much then a TRUE ballistic coefficient can be derived from Joe's 300 yard reading vs. his muzzle velocity. Joe's velocity at 300 yards will show a "slugged up" boolit if it has changed much. That's my interest.
Eutectic
Eutectic,
What do you mean by my bullet may have collapsed? Another way of saying compressed? Here's what I think. There is no doubt there's a difference in my bullet shape before and after firing. I'm sized at .268 and the groove on my Swede is .266-?. So no doubt it's being squeezed into those narrower groove not counting the even more narrow bore. With that said the metal has to go somewhere and that somewhere is length. The length would have to get longer then. So now we have a skinnier and longer bullet then the original unfired one. That should raise the BC I believe . If I'm wrong someone correct me.
Not saying anyone is stepping on any toes here, but let's keep our cool because this thread has done well. So if someone says something that doesn't go down your gullet quite right, try to swallow it and discuss it without a contest. God, nobody knows this more then me because I really get under many member's skin. I hope I'm past that now.
I forgot to say that I've recovered many of those bullets and have been able to get a diagnosis of what's going on in the bore and can definitely say the deep groove fast rifling twist isn't visibly stressing threm.
Joe
Eutectic
"Joe is driving a rather soft boolit at 2300 fps. Add to that, the additional compressive longitudinal load from pushing into a very steep twist... Does Joe's 6.5 boolit take this in stride, or does it collapse some under load?
Therefore... my interest in Joe's 300 yard velocity reading is a measuring tool. Did Joe's bullet change in its coefficient of form during launch? If it collapsed much then a TRUE ballistic coefficient can be derived from Joe's 300 yard reading vs. his muzzle velocity. Joe's velocity at 300 yards will show a "slugged up" boolit if it has changed much. That's my interest."
There is no doubt the bullet is compressing. As Joe mentions there is some tentency to lengthen but with the rapid accelleration and being forced into the fast twist the acts of lengthening is counteracted by the compression. The bullet does compress and it is back into the groove area where it can compress as the lube is forced out. The result is a shorter, squatter bullet shape with a lower BC. That softer cast bullets end up being more accurate at high velocity is, I believe, because they compress evenly whereas a hard bullet may compress more on one side or the alloy may chip off on the driving bands.
Thus the softer bullet at HV stays more balanced and is less affected by RPM. I attempted to explain all of this during the RPM threshold testing I conducted. I actually do measure the BC of the bullets (based on measured muzzle velocity and 100 yard velocity) with the M43 PBL. My tests so far with soft cast bullets vs hard cast bullets out of the same mould in the 6.5 Swede show the BC of the soft cast bullets decreases at a higher rate as velocity is increased vs the hard cast bullets. That is factual proof of the set back and compression of the softer bullets as evidenced by the smaller BC.
However, my factual findings were boo hooed to no extent and ignored during the tests. I imagine the same will happen here. Eutectic, bottem line is you are correct.
Larry Gibson
This quote may best describe my term collapse.... Shortening in length. I'm not talking torque forces, although they could be present with the Swede's twist rate. If you have fairly pristine recovered bullets one can look at lube groove wide/depth. Impact with anything hard can trick you as they will shorten then too. Mike the O.D. on recovered slugs as hard impact usually expands diameter as well.
In worse case scenarios. The nose can collapse some during acceleration. I doubt this is your case however.
Might be difficult in Tennessee, but I find a huge drift of fresh dry snow the best for checking fired slugs. (Easy to say here in the Rockies!)
I bought a hundred "Keith" boolits years'ago from a guy. They were 429421's that were hollow pointed. Supposed to be 1 in 16 alloy. Nicely cast, so I bought them, soft as they seemed. I should have hardness tested them but I didn't. They shot pretty decent; but I noticed some holes were "cut" sharper than others in the target. But they were just coyote loads. It was winter so I shot a cylinder full into a BIG drift out back on a whim. Forgot all about them come spring (this is a slow testing process!) I was walking towards my 70 yard target when I found a Keith boolit on the ground. Some searching found two more. THEY LOOKED LIKE SLIGHTLY MUSHROOMED WADCUTTERS!! I showed them to a buddy explaining how they had collapsed in the revolver.
"How do you know that!" He tooted.
"Look at them! The rifling goes their full length!" I returned.
Cast boolits can be full of tricks.
Eutectic
Larry, you were not laughed at by me!! ... felix
felix
This quote may best describe my term collapse.... Shortening in length. I'm not talking torque forces, although they could be present with the Swede's twist rate. If you have fairly pristine recovered bullets one can look at lube groove wide/depth. Impact with anything hard can trick you as they will shorten then too. Mike the O.D. on recovered slugs as hard impact usually expands diameter as well.
In worse case scenarios. The nose can collapse some during acceleration. I doubt this is your case however.
Might be difficult in Tennessee, but I find a huge drift of fresh dry snow the best for checking fired slugs. (Easy to say here in the Rockies!)
I bought a hundred "Keith" boolits years'ago from a guy. They were 429421's that were hollow pointed. Supposed to be 1 in 16 alloy. Nicely cast, so I bought them, soft as they seemed. I should have hardness tested them but I didn't. They shot pretty decent; but I noticed some holes were "cut" sharper than others in the target. But they were just coyote loads. It was winter so I shot a cylinder full into a BIG drift out back on a whim. Forgot all about them come spring (this is a slow testing process!) I was walking towards my 70 yard target when I found a Keith boolit on the ground. Some searching found two more. THEY LOOKED LIKE SLIGHTLY MUSHROOMED WADCUTTERS!! I showed them to a buddy explaining how they had collapsed in the revolver.
"How do you know that!" He tooted.
"Look at them! The rifling goes their full length!" I returned.
Cast boolits can be full of tricks.
Eutectic
Give yourself some credit here man. I've only been here a short while but your posts are extremely valuable. Nobody can be good at everything. My wife is a gifted accountant but you know how she passed English 202? I told her to give me her research paper and walk away then when she went to hand it in she wanted to read it and I told her just to turn it in. I've worked with PHD's who can't spell and I've worked with Engineers who are very good at what they do in the computer field, but have the personality of a tomato and couldn't instruct anyone to do anything.
The reason I write well, according to wife, is that I'm so full of poop I like to hear myself talk as well as write..............
Joe's volunteered and if he needs help just ask and I'll be happy to.
Art
”Only accurate rifles are interesting”
——Townsend Whelen
In a time of universal deceit , telling the truth is a revolutionary act
—- George Orwell
The title of this thread caught my interest and I have been following along picking up bits of information here and there but there is still lots to learn.
I hope the thread keeps developing and the guys that know will share enough to help the guys who are eager to learn. Like I said, I am all ears and waiting for more details.
I have learned a tremendous amount on this site in the last few years and I read lots of posts by people like Larry Gibson, Starmetal, 45 2.1, Felix (to name a few knowledgeable people on this thread) and a host of others, always learning something.
This thread may be about the 6.5 Swede but the principles that allow Joe to get the results he does can be applied to other cartridges as well.
I am interested.
Longbow
BP | Bronze Point | IMR | Improved Military Rifle | PTD | Pointed |
BR | Bench Rest | M | Magnum | RN | Round Nose |
BT | Boat Tail | PL | Power-Lokt | SP | Soft Point |
C | Compressed Charge | PR | Primer | SPCL | Soft Point "Core-Lokt" |
HP | Hollow Point | PSPCL | Pointed Soft Point "Core Lokt" | C.O.L. | Cartridge Overall Length |
PSP | Pointed Soft Point | Spz | Spitzer Point | SBT | Spitzer Boat Tail |
LRN | Lead Round Nose | LWC | Lead Wad Cutter | LSWC | Lead Semi Wad Cutter |
GC | Gas Check |