quote:

Originally posted by DocWestFMF:

Ok, so i won't waste my time trying to figure it out. I figured knowing how to find the SD of a round would come in handy if I didn't have the name of the maker or the style of the round.

Not completely a waste of time. The sectional density really comes into play between the muzzle and the target.

Internal ballistics - what happens between the ignition of the primer to when the bullet exits the muzzle

External ballistics - what happens between the muzzle and the impact

Terminal ballistics - what happens after the bullet arrives at the impact site, including wound channel, etc.

Sectional density has a lot to do with how fast the bullet will lose velocity to air drag. The theoretical flight path of a bullet fired in a gravitational field is a parabola, but when you include the fact that the bullet is changing velocity throughout its flight, it becomes easier to run a few hundred experiments and compile a table that relates B.C. and speed to bullet drop than to try to calculate the flight path to expect in reality based on theory.

You really want to warp your mind? Find the thread that discussed the effects of raindrops the bullet may encounter between muzzle and target.

Have fun.

Lost Sheep

LS

quote:

Sectional density has a lot to do with how fast the bullet will lose velocity to air drag.

You want to think about that a little more?
Given that a 30cal 180gr DEWC has the same SD as a 30cal 180gr ULD, just how is it that the SD has any effect on the ballistic curve? IOW what effects the curve is the Ballistic Coefficient, not the SD.

I may have to bow to your greater knowledge. I have been known to be wrong on occasion.

I believe they are more or less intimately related.

Sectional density is the ratio of an object's mass to its cross-sectional area. It conveys how well an object's mass is distributed (by its shape) to overcome resistance. For illustration, a needle can penetrate a target medium with less force than a coin of the same mass. When a projectile is in flight or impacting an object, it is the sectional density of that projectile which will determine how efficiently it can overcome the resistance to air or object. The greater the sectional density is for a projectile the greater its efficiency is and therefore ability to overcome the resistance of air and object resistance of air and object.

http://en.wikipedia.org/wiki/Sectional_density

In ballistics, the ballistic coefficient (BC) of a body is a measure of its ability to overcome air resistance in flight

http://arxiv.org/ftp/arxiv/papers/0705/0705.0389.pdf

Could it be we are both right? I will give you that you are probably more right than I am.

Lost Sheep

And one wonders why the newbies become confused when the retoricians begin to emote.

LS
IF (big if) you're using the same design bullet (IE: a round nose) the heavier one will have both a higher SD and BC. In this case you could say that the SD has an effect on the curve (even though it's a indirect one).
If your using 2 different designs of the same weight however, the SD stays the same while only the BC is effected. In this case, the one with the higher BC will shoot "flatter".

With the same design (and construction), the heavier one will tend to penetrate deeper, but again if you alter the design/construction of one bullet, even that "rule" goes out the window IE a 180gr Ballistic tip (designed to open) VS a 150gr copper solid (designed to retain it's shape).

The whole SD discussion was in vogue back in the 50's & 60's, when bullets were basically all the same construction (un-bonded cup & core) with only a couple basic designs, but with today's multitude of designs, bonded cores, controlled expansion and solid copper bullets it's fallen by the wayside.

ok, you guys are starting to speak greek. I understand that a higher BC means a flatter trajectory, is there a way of figuring out how much a bullet will drop over "X" yards with a BC of "Y"?

Please see my above post. You'll learn to ignore it when a couple of folks start splitting a hair and arguing about the thickness.

quote:

Originally posted by DocWestFMF:
ok, you guys are starting to speak greek. I understand that a higher BC means a flatter trajectory, is there a way of figuring out how much a bullet will drop over "X" yards with a BC of "Y"?

Yes
There are a number of "ballistic calculators" (Google is your friend) on the web (and even a couple smart phone apps), simply punch in the BC, muzzle velocity and zero distance. Some will also let you input temperature, wind speed & direction, altitude and some other environmental conditions that effect the bullets flight.

quote:

Originally posted by DocWestFMF:
ok, you guys are starting to speak greek. I understand that a higher BC means a flatter trajectory, is there a way of figuring out how much a bullet will drop over "X" yards with a BC of "Y"?

DocWestFMF,

Sorry about helping you into the deep end.

As an experienced shooter (How much experience do you have, anyway?) I assumed you know about bullet drop and how fast bullets lose speed by air drag and how that affects the trajectory.

Those are complexities you will want to know about whether you reload or not.

But for loading, I suggest you wait on that study for a while.

I suggest you do things in this order:

1) Learn the mechanics of loading. How to prepare brass, how to insert & seat bullets, how to crimp, etc. Follow the load recipes you find in the manuals and don't try to get fancy pushing performance envelopes.

2) When you have the mechanics down pat, start looking into tuning your loads for best performance (picking powder/bullet weight combinations that give the power level you want with efficiency).

3) After that, you start working on selecting bullet shapes the give the external (flight) and terminal (effect on the animal) ballistics you seek.

There is plenty of time to delve into the fine points.

Don't let anything distract you from the first task: Learning how to safely assemble cartridges that are safe and uniform. Don't let anything distract you from the first task: Learning how to safely assemble cartridges that are safe and uniform.

Lost Sheep

p.s. wasbeeman, thanks for introducing a note of sanity. Too many times, threads get off on tangents. I am happy to apply a course correction to fix my distraction.

Hey guys, sorry I haven't been on in awhile, and I won't be for a bit more. The internet access at my base got fried a few weeks ago and we won't be getting it back before I come home. So I"ll read, and re-read everything again, then hit ya'll up again later. Till then, Thanks for everything!

Doc

Gosh, I wish that I had gotten to ask WHEN the good Doc is coming home. Now I will just have to wonder...
Not that it will do so much good as if he were actually able to read this addition, but I would like Doc to know that there are good, decent, and caring people who are behind him and his brethren 100%
At the risk of touching off a political debate, I would like to see a statistical study done. I think it would be interesting to see what the numbers say in a comparison of gun ownership, forum membership, political affiliation and the supporting of the soldiers like our friend Doc. I would venture to say that our membership/readership don't include a lot of bleeding heart liberals....
But let's stay on topic.
Supposing Doc has the opportunity to check in while he is still in the sandbox; I suggest he talk with his marksman and sniper friends and see if any of them have the ballistic calculator app as a part of their hardware. I read an article a few weeks back where some branches of the military are issuing some snipers a "package deal" as designed by Knights Armrament.
Included in that package is a ballistic calculator that is the mil-spec version of a ballistic computing app that civilians can have on their I-phones or I-pads.
Doc, if you can lay hands on one of these, or just get the name of the program and some specifics, you can play around with the program, insert different numbers in different places, and watch what the results are.
This might be a good way for you to familiarize yourself with the effects that varying sectional density, ballistic co-efficents Ect. have on the flight path of a particular fired round.
When you return to the civilian life, you can have a program that you are familiar with and are able to use effectively.
And even if you can't get hold of the exact same thing as the Marine Snipers use, there are many good programs to be had at very reasonable prices. They range from the basic to the terribly complicated as well, for the ballistician who likes to take every detail into account; as I suspect that you may want to, Doc.
My thoughts and prayers for all the best.

quote:

Originally posted by jaybald1:
Gosh, I wish that I had gotten to ask WHEN the good Doc is coming home. Now I will just have to wonder...
.....Very Very soon....
Not that it will do so much good as if he were actually able to read this addition, but I would like Doc to know that there are good, decent, and caring people who are behind him and his brethren 100%
Thank you very much. I really do appreciate it.
At the risk of touching off a political debate, I would like to see a statistical study done. I think it would be interesting to see what the numbers say in a comparison of gun ownership, forum membership, political affiliation and the supporting of the soldiers like our friend Doc. I would venture to say that our membership/readership don't include a lot of bleeding heart liberals....
probably not.......
But let's stay on topic.
Supposing Doc has the opportunity to check in while he is still in the sandbox; I suggest he talk with his marksman and sniper friends and see if any of them have the ballistic calculator app as a part of their hardware. I read an article a few weeks back where some branches of the military are issuing some snipers a "package deal" as designed by Knights Armrament.
Included in that package is a ballistic calculator that is the mil-spec version of a ballistic computing app that civilians can have on their I-phones or I-pads.
Doc, if you can lay hands on one of these, or just get the name of the program and some specifics, you can play around with the program, insert different numbers in different places, and watch what the results are.
This might be a good way for you to familiarize yourself with the effects that varying sectional density, ballistic co-efficents Ect. have on the flight path of a particular fired round.
When you return to the civilian life, you can have a program that you are familiar with and are able to use effectively.
And even if you can't get hold of the exact same thing as the Marine Snipers use, there are many good programs to be had at very reasonable prices. They range from the basic to the terribly complicated as well, for the ballistician who likes to take every detail into account; as I suspect that you may want to, Doc.
My thoughts and prayers for all the best.

I did get a chance to talk with some snipers and talk about the Ballistic Apps that they use. I will be looking closer at those once I get back.
I am very close to coming back to the world, and can't wait.

Good to hear you will be home soon.
I will keep an eye out for your name showing up around here.

I'll be home sometime this weekend

Got the ISnipe app for my phone and just been playing around with it....FREAKING AWESOME!

I have used I Snipe almost exclusively for the last year or so. In fact, the promise of a ballistic calculator was the number one reason for the purchase of my I Pad.
I Snipe is a good program, within it's limitations. It is pretty easy to use and has about the right level of complexity for me to handle. Whilst shopping around I looked at various programs and found some that had so many input variables... Well, it was too much for me!
I Snipe is just about right for me.
Remember a little while back, some of the readership talked a bit about ballistic programs and the way they calculated a trajectory based on a set of "perfect world" scenarios? I might recommend doing a little reading about how these programs tick... You might be surprised.
Also, I strongly recommend that you read anything you might come across that has been written by Bryan Litz. He has been doing some interesting work with ballistics and consequently has improved ballistic calculation as we know it. I read where he is working for Berger Bullets nowadays.

Anyhow, are you home yet? For good?

A thought occurrs to me; as we began this discussion about reloading after all.
But following the thought about programs that we can use to assist our loading and shooting, I wonder if you are familiar with Quick Load?
I think that playing around with the Quick Load program might better satisfy your curiosity tword some of the earlier questions we talked about. Now, I only wish I had a copy of this program, but I know it is highly regarded among the shooting and reloading communities.
As I understand it, the user has the ability to change the variables and look at the results, similar to the I Snipe program we use.... But Quick Load takes it a step further, allowing changes in certain variables that we do not have access to with I Snipe. 'Fer instance...
Referring back to a post you made on Feb.15th: about the mathematical formula to see what results are to be expected by altering pressure, velocity and the like. Well that's what Quick Load is all about!
That program can tell you how much pressure, so much of whatever powder, will make and that it will push such-n-such bullet at what have you feet per second; and allow you to change those variables. Most importantly, it tells you what not to do, in that it will warn you of dangerous over pressure or "too hot" of a load. It is, I suppose, like a virtual ballistics lab, right at home.
If nothing else, it seems to me it might save time and money, experimenting in virtual reality with virtual bullets and virtual powder. It might even save someone's virtual life...

I will say this at least Doc, it might be worth looking into and thinking about......

Jay,
yea, I'm finally home. Got in Sunday morning. Been a busy few days since then, sittin through classes, and spending time with the family.
I will look into that Quick Load program, got another one that I ordered while I was deployed, think it's a tracking system, not sure yet. But for the moment, I'm happier than a tornado in a trailer park just to be home.

Good to hear you are back home and safe.
Take a bit to settle in and play around a bit with those programs. I know there is a lot to be learned from them and I expect you can have more fun than a barrel of monkeys with them.
Consider this an official invite to look up my personal e mail one of these days and shoot a message this direction. I will be happy to answer any questions that might arise in the course of your reloading career. Correct answers...well, that might be another matter all together. But, in my short time of learning to load, I have probably made most of the mistakes that it is humanly possible to make.
Furthermore, I wouldn't mind just shooting the bull some time too, if you have nothing better to do.

At any rate, it's good to hear from you. I will be keeping an eye out for you...

Hi, I'm new here and just wanted to throw in my opinion of loading manuals, based on the bookshelf of them that I have. They are all the same, basically. They will give you the basics of reloading, safety precautions, which a lot of people choose to ignore, a couple of teaser articles that may or not have appeared in earlier editions, load data, detailed info about their products, and most will give a little history and or technical tips about each cartridge.

What you buy should be based on what you need information for. I have read a couple of copies of the ABCs of reloading and Reloaders Digest, but they had nothing to offer that I hadn't already read elsewhere. The basics are the basics and don't change because they hire a new editor, and the same goes with most of the reloading manuals if you look at successive editions.

The only loading manual I don't care for is Lee's, either edition. They get their data from other sources and it is impossible to make an apples to apples comparison of the data listed for any caliber/bullet listed. Other than that, if you want a loading manual try to get one that is from the bullet/powder manufacturer that you want to use. Also Lymans are great if you load a lot of different types of bullets and powders.

But there is another route you can consider. Get a book on "handloading" and then use all the free online, or complimentary data available for the ever changing "loading data". This will save you a lot of money.

There are numerous books on the subject of handloading, many of which are not too different from one of another, but my two favorites are "Modern Handloading" by George C. Nonte, which is easy to read and goes well beyond the beginnings, and "Principles and Practice of Loading Ammunition" by Earl Naramore, which may be a little technicle for some readers, but you will find a lot more valid information in it than you will on the internet. Both of these are out of print but can be found using bookfinder.com

Well, first things first, let me welcome you aboard, and we are glad to have you. The folks here in the forums are like one big family. Actually, very much like one big dysfunctional family in fact! We argue, disagree, squabble and refuse to speak to one another rather often.
You will see Uncle Bob telling Cousin Willie that he is a fool and couldn't manage to load a wheel barrow without a road map... Then, if someone else talks bad about ol' Willie, Uncle Bob will be the first to get angry and stand up for the same person he was calling a blithering idiot the very last week!
Stick around for long enough and you will see remarkable feats of marksmanship the likes of which Carlos Hathcock himself couldn't match! You will hear accounts of expert hunters, making the very earth tremble with the recoil of their rifles, and the elephant they just shot hitting the ground. Still others will recount leaping from tall trees to bare handedly wrestle cougars and bear to their trophy rooms.
I don't mean to imply that everyone is a liar or braggart; just most of us. In all seriousness, there is good, sound and useful information to be found around here, if you can sift through all the horse droppings and find it!
I hope you will be entertained and who knows, you might learn something too.

But, I digress from the topic.
This dude has a valid point Doc. I too have noticed that some of the manuals seem to repeat their information or steal if from one another. As pointed out, the basic set of skills needed to safely and correctly assemble ammunition is not going to be different just because you pick up a different book.
These days the net is chock full of how to type information about reloading. There are good videos on You Tube and Ammosmith to name just a couple. I refer to them every once in a while myself for this and that.
I would say it would be possible to do a bit of Internet research and find everything you need to reload from the how to basics right down to the recipes. I do know that most of the powder manufacturers have pages that you can reference to look up how much powder to charge your ammo with. They are, in my experience, just as good, if not better than what I have found in some reloading manuals.
I guess, at the end of the day, it comes down to each persons individual needs and preferences. Myself, I don't have an Internet connection or computer at my reloading bench and I like to have a book that I can hold in my hand and look back to if I have any questions. Just because it's the way I like to do things in no way makes it the only way, or even the right way, to do it.

Hello again to our new friend and to all. I'm off to see if I might find something, target or game, that looks like it might need shooting.

Thanks for the welcome jaybald1. I've been on a couple of other forums and the spat'n and spite'n sounds familiar, in fact it can be pretty entertaining at times.

But one thing I could never figure out is how people respond to the bragging. Wether or not the poster has really done the feat doesn't matter, I still like to hear about them just so I can try to do it myself. (I've been like this ever since I read Ed McGiverns book.) But there are people that will quickly claim anything they can't do is impossible, instead of asking how it was done so they can learn something.

I noticed your location, are you near Carter County?

ok, so I finally got around to cracking my ABC's and Lyman's. Is it possible to use the same 30 cal round for a 308 and a 7.62x54R?

In short, no.
While both are nominal 30 cal / 7.62mm, there are many differences
308/7.62 NATO uses a .308 diameter bullet, and has a rimless case that's 51mm long
7.62 Russian normally uses a .311 diameter bullet, and has a rimmed case that's 53.5mm long. It can be loaded with 308 slugs, but accuracy won't be up to par

There is a reported/possible (unsafe, desperation / gorilla warfare usage only) way to use the 308 round in a x54R rifle, for the purpose of taking the other guys weapon/ammo.

Thanks for asking our advice.

[QUOTE=DocWestFMF]
ok, so I finally got around to cracking my ABC's and Lyman's. Is it possible to use the same 30 cal round for a 308 and a 7.62x54R?[/QUOTE]
Short answer is "Yes".

Long answer: Some nominally 30 caliber bullets are not exactly 0.300", so a good micrometer is good to have, but if (and it's a big if) if the diameter of your bullet fits your bore, you are good to shoot it.

Now, the twist rate of your barrel will determine what velocity you will get good accuracy (spin too slowly and you have stability problems, too fast and a fragile bullet may actually come apart in flight). Typically barrels mated with particular chambers/cartridges will have a twist rate correct for the bullet weight and velocity associated with that cartridge. For an extreme example, you could shoot a bullet intended for the .30 Carbine out of a 300 Winchester Magnum, but you likely will get poor performance. It will shoot, though.

This is the two-edged sword of handloading. You can pick a bullet and velocity and tune the weight and speed until you get the performance you want. But that means you have to think hard about it.

Better a two-edged sword than no sword at all, eh?

Good luck.

Lost Sheep

ok, so short answer......no .308's in the 7.62X54R...Got it. Time to do some more reading......After I clean my room....LOL

Well, guys, finally have most of my stuff for reloading. I'll lost pictures up later. I'm gonna need to get a 2x8 to bolt everything to so I can set up on the kitchen table. No where else to do it right now. Just need to get some dies. Looking to sell the ones I have, cause they are all the wrong caliber. Let me know if anyone is interested. I'll post up die calibers tomorrow.

Ok. Busted everything out today, and I know the first thing I need are .308 dies and a 2x8. However, I have some 7mm Mag, and 357 mag dies that i'm not going to use. So if anyone has some .308 dies (prefer RCBS) that you would want to trade, let me know. Pics later today cause I know I am missing parts to one of the presses. Also have a set of RCBS FL 8X57 Mauser dies.

Don't be too quick getting rid of those dies. You never know when an urge to own a big 7 or a 8x57 might rise up and overwhelm you. Just saying......
I picked up so much range brass in .223 that I had to buy a rifle for it. And, I already had a set of dies for some reason.

I don't keep things around that I don't have a use for, and I have more use for the money that i would get from selling them, like buying .308 dies......

Ok, so how many different dies do I need. and how valuable is having a Precision Mic Die?
I know I need different dies to replace the primer, resize the neck, and to seat the bullet. Anything else that I am missing.

Doc, reading a good load book would answer a lot of your questions. Reading one or more of the books is highly reccommended by most if not all experienced reloaders.
Just sayin'....

quote:

Originally posted by DocWestFMF:
Ok, so how many different dies do I need. and how valuable is having a Precision Mic Die?

If your going for absolute minimum groups, the PMD has the advantage of allowing you to change the seating depth by .001 without a lot of fussing around. Handy, but a ton of quality/accurate ammo has been loaded on the "standard" style.

quote:

Originally posted by DocWestFMF:I know I need different dies to replace the primer, resize the neck, and to seat the bullet. Anything else that I am missing.

The sizing die pushes out the primer at the same time it sizes down both the neck and the case body. As you remove the case from the die* the expander rises through the neck bringing it UP to the correct diameter.

Primers are installed either with the press, or a hand priming tool (no die needed)

*For bottleneck cases, on straight wall cases a separate expander die is used to flare the mouth to accept the bullet.

ok, still trying to sel the dies that I have. All are in really good condition, and I know that brand new, these are going for about 20-40 Dollars. So would 20-25 be a fair price to ask?

Yes