The Firing Line Forums

Go Back   The Firing Line Forums > The Skunkworks > Handloading, Reloading, and Bullet Casting

Reply
 
Thread Tools
Old August 8, 2012, 09:07 PM   #1
ATPBULLETS
Senior Member
 
Join Date: July 31, 2012
Location: Land between the Lakes
Posts: 194
Is there "something" pushing velocities...?

This is a question i have wondered....

In all our reloading manuals.....there is published velocities....with a given type and amount of powder and bullet....,,..... lets say powder A vs powder B.....
Powder A has a published velocity of 3000 fps....
Powder B has a published velocity of 3100 fps...

So, on the face of it...powder B will deliver more velocity and more "punch"....... but my question is this in the above example......

Is there characteristics of a powder that deliver more "punch",,, than what the numbers indicate... ie, are there inherent characteristics in some powders that do not show across a chronograph...???
thanks for responses....
ATPBULLETS is offline  
Old August 9, 2012, 02:59 AM   #2
noylj
Senior Member
 
Join Date: October 21, 2007
Location: Between CA and NM
Posts: 506
Not sure what you mean.
Slower powders spread out the peak pressure and can achieve higher velocities--depending on barrel length to let the powder do its job.
If you want more velocity, you move to slower powders, until you reach the point where the powder is too slow to achieve any velocity increase in the barrel length you have.
If you want slower target loads, you move to faster powders.
This is true for all firearms.
noylj is offline  
Old August 9, 2012, 06:08 AM   #3
ATPBULLETS
Senior Member
 
Join Date: July 31, 2012
Location: Land between the Lakes
Posts: 194
Whaat i'm asking is there any "magic" in some powder combos.....
that muzzle velocity numbers do not reveal..?

Let me ask it this way..... are there any powders that push a bullet better than what there muzzle velocity reveals....?

If you were to set up chronys down range for all the powders for a given caliber bullet combo.... would there be any powders that hold their velocities better than others,,,????
ATPBULLETS is offline  
Old August 9, 2012, 06:20 AM   #4
jephthai
Senior Member
 
Join Date: July 5, 2007
Posts: 463
Nope, no magic. Once the bullet leaves the barrel its up to the bullet to keep its velocity. That's what ballistic coefficients (BC) are all about. Some bullets are more aerodynamic than others, and there are lots of factors that influence this quality. Powder is not one of them -- once the bullet leaves the barrel, powder's job is done.

Sent from my DROID4 using Tapatalk 2
jephthai is offline  
Old August 9, 2012, 06:49 AM   #5
Bart B.
Senior Member
 
Join Date: February 15, 2009
Posts: 5,463
ATPBULLETS asks:
Quote:
Is there characteristics of a powder that deliver more "punch",,, than what the numbers indicate... ie, are there inherent characteristics in some powders that do not show across a chronograph...???
Yes.

Most notable is that powders giving the highest muzzle velocity with a given bullet at safe pressures typically do not produce the best accuracy with that bullet. This usually happens with slower burning powders. Best accuracy tends to happen with powders in the middle range of what's used for a given cartridge.
Bart B. is online now  
Old August 9, 2012, 11:25 AM   #6
Edward429451
Junior member
 
Join Date: November 12, 2000
Location: Colorado Springs, Colorado
Posts: 9,494
The magic is in the barrel length. Longer barrels achieve higher velocities for the most part. Longer barrels let you achieve your target velocity with less powder and pressure. It is the loaders job to match the proper burn rate, and charge to barrel length to achieve optimum results. I guess I am saying that if there is any magic afoot, it is the reloader himself.

Barrel length plays a big part. The man with a snub nose is going to have to use heavier charges of a fast powder to even get close to the velocities that the man with a 6" or longer barrel will.

I routinely get max charge velocities, with starting loads of powder in my 6-7.5" handguns, but they don't carry as easy as snubs do. There's a trade off. Sort of a Tortoise and the Hare thing. Sort of.
Edward429451 is offline  
Old August 9, 2012, 12:41 PM   #7
Sevens
Senior Member
 
Join Date: July 28, 2007
Location: Central Ohio
Posts: 9,196
Just want to make the point that published load data should not be interpreted as computed formula results to be followed to the letter. What I mean is -- published data is simply a grid that shows you all the stuff they used, in the platform they used it... with the results they found.

What happens when all those components are assembled is NOT written in stone. Published load data is a guideline and a test result.

There could be other factors that caused them to list Powder A at a certain "maximum" load -- perhaps an extreme temperature sensitivity or other wonky variable that kept them from working the load further. In that case, there may be room to advance Powder A and take it past what they show as a top result for Powder B.

Published data is a terrific resource. It's a starting place for your own experiments and it's (hopefully!) a safe set of guidelines worked up in a laboratory with quality equipment by quality people. But at the end of the day, it truly is nothing more than a published set of test results.

When we work up a load with the hope/plan of making a pet load out of it, we are doing much the same thing, without the equipment, facilities and bankroll that they have.
__________________
Attention Brass rats and other reloaders: I really need .327 Federal Magnum brass, no lot size too small. Tell me what caliber you need and I'll see what I have to swap. PM me and we'll discuss.
Sevens is online now  
Old August 9, 2012, 06:38 PM   #8
wncchester
Senior Member
 
Join Date: December 1, 2002
Posts: 2,832
"...ie, are there inherent characteristics in some powders that do not show across a chronograph...???"

No. The fastest bullet of a given weight has the biggest impact/punch no matter what powder was used. Accuracy is a seperate issue and no powder has any automatic magic for that.
wncchester is offline  
Old August 10, 2012, 03:15 AM   #9
Sevens
Senior Member
 
Join Date: July 28, 2007
Location: Central Ohio
Posts: 9,196
Using the same quoted bit -- but a little bit out of context, there certainly ARE some characteristics of powders that indeed may not show up in a chronograph. Not with regards to more "punch" or "power", but some that can still be advantageous.

For example -- you can sometimes pull the same or a similar velocity as Powder A, but do it with less peak pressure with Powder B. Or maybe you can match the velocity using a smaller charge weight... which could save you a little money in the long run. Maybe you can do it with a powder that easier for you to get locally, or maybe you can do it with a powder that meters better through your equipment. Could be that you could substitute a powder that gives you a similar velocity, but can also be used in another chambering where Powder A could not.

Short version: there's MANY reasons we can pick from so many different powders, and so many of us do exactly that.
__________________
Attention Brass rats and other reloaders: I really need .327 Federal Magnum brass, no lot size too small. Tell me what caliber you need and I'll see what I have to swap. PM me and we'll discuss.
Sevens is online now  
Reply

Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -5. The time now is 08:51 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
This site and contents, including all posts, Copyright © 1998-2014 S.W.A.T. Magazine
Copyright Complaints: Please direct DMCA Takedown Notices to the registered agent: thefiringline.com
Contact Us
Page generated in 0.09445 seconds with 7 queries