Since I've been posting web calculators . . .
 

Since I've been posting web calculators i thought I would post the web-based ballistics calculator which I use. Its called the JBM Trajectory Calculation Page and can be accessed here:

http://www.mega.nu:8080/traj.html

Be sure to put this one in your favorites.

Happy Hunting, Phil

RE: Since I've been posting web calculators . . .
 

thanks for the link.. very interesting.

RE: Since I've been posting web calculators . . .
 

Pglasgow,since you use JBM anyway have you ever played with the Greenhill formula that tells you what length a bullet should work best in what twist.I found it quite helpful in picking bullets to try. Lee

RE: Since I've been posting web calculators . . .
 

Is that

Mininum Rate of twist = (150 x dia^2)/Length of bullet

?

I use that one, the same?

RE: Since I've been posting web calculators . . .
 

Guys,

Wow! I am engineering and work for Magna Powertrain in Syracuse, NY. I like to work with equations. After, I read this forums and it makes me want to put all equations into excel spreadsheet. Let’s share the formulas and we could put them into one good program and can be useful for all of us.

I want to tell you who I am. I am hearing impaired and my first language is America Sign Language (ASL). English is my second language. I am sure you will notice that my grammar is not that good. Please be bear with me. Thanks…

I just purchased T/C Omega and only shot 10 times. I really love this sport. I have been hunting with bow and shotgun since 1984. Muzzleloading is new to me therefore I need to learn what the terms are.

Thanks,
DFHunt19
[:-]

RE: Since I've been posting web calculators . . .
 

DFHunt19,

Welcome to the Forum :). And welcome to muzzleloading. You are going to have lots of fun with it. An excel program would be great. Let us know how it goes.

Happy Hunting, Phil

RE: Since I've been posting web calculators . . .
 

Pglasgow,The same,I find it handy to help pick out what I want to try. Used to use it when building Hawken rifles. Lee

RE: Since I've been posting web calculators . . .
 

Not quite the same, but the online design program at mountainmolds.com is an interesting tool. Not only can you design a mold but, guesstimating backwards :D, you can take a look at numerous other properties including recommended twist. Understand from multiple sources that his molds are of the highest quality as well.

RE: Since I've been posting web calculators . . .
 

First off .. welcome to the forum. It's great to have you here.

You've got a great rifle there and a lot of people on the forum shoot them. I am sure they will be more then glad to answer your questions and exchange information about loads with you.. Any questions you have, just feel free to ask away...

RE: Since I've been posting web calculators . . .
 

Thanks PG!

RE: Since I've been posting web calculators . . .
 

Welcome DF!

RE: Since I've been posting web calculators . . .
 

DFHunt19, welcome to the group.I like your idea there are several of use thinking along those lines. Lee

RE: Since I've been posting web calculators . . .
 

Underclocked wrote:

Not quite the same, but the online design program at mountainmolds.com is an interesting tool. Not only can you design a mold but, guesstimating backwards :D, you can take a look at numerous other properties including recommended twist.

Thanks for this post, I've been playing with the bullet designer. I was surprise to find that I had to go to as low as 300 grainsin .50 cal to get the reccomended twist to 1:48. Hmmmm.

Happy Hunting, Phil

RE: Since I've been posting web calculators . . .
 

Mountain Molds Cast Bullet Molds

RE: Since I've been posting web calculators . . .
 

Unlike Greenhill, the MM program takes into account several other variables besides caliber and overall length. Nose length and bullet to bore contact length come to mind. Contact length seems a critical consideration (at least to me).

RE: Since I've been posting web calculators . . .
 

Underclocked wrote:

Unlike Greenhill, the MM program takes into account several other variables besides caliber and overall length. Nose length and bullet to bore contact length come to mind. Contact length seems a critical consideration (at least to me).

Do you know if they mean:

Use this twist or slower.

Or, Use this twist or faster.

Or, this twist is optimum

?

Happy Hunting, Phil

RE: Since I've been posting web calculators . . .
 

I think the program projects the optimal twist. I just now put in some numbers: 320 grainsand chose the truncated cone with a .3 nose, 60% meplate, no crimp groove, shortened the base and the upper band somewhat, and the picture looked very similar to a LEE REAL bullet of that weight. The optimal twist indicated was 1:42 which is probably close to reality. The 1:48 twist has long been regarded as a compromise twist that is capable of handling roundball or conical.

RE: Since I've been posting web calculators . . .
 

All,

I was exciting and jump into this subject and was not thinking that I need to finish my living/dining room remodeling. My wife has been waiting for me to finish the project.[:o]

After, I replied the message to this subject. I realized that it won’t be easy task. We will start with very simple equations and build into what we want to see on the graphs and data in the MS Excel spreadsheet. Please be bear with me until I finish the living/dining room for my wife then we will start to work on Trajectory Calculation.

Thanks,
DFHunt19
:)

RE: Since I've been posting web calculators . . .
 

I was on break time and decided to search the information via www.google.com and found a MS-Excel program (http://www.jacksonrifles.com/files/p...ballistics.xls). Maybe, we will play around with this program and see if we could modify to our taste. That will save our time! Check them out and let me know.