The Firing Line Forums

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

Reply
 
Thread Tools
Old February 22, 2000, 04:14 PM   #1
Banzai
Senior Member
 
Join Date: January 29, 2000
Posts: 275
What is the advantage in commercial ammo loaders loading +P or +P+ loads when similar or better velocities can be be achieved with a simple change of powders? I know that reliability and unifromity of burn are a factor, as well as muzzle flash, but are there any other reasons? Is there any gain either in internal, external, or terminal balistics to support this?
I'm wondering because I reload practive rounds to factory velocities, and often I can duplicate the velocity of +P loads with much lower (read "published safe") recipes. I do know that there have been a few cross overs from non canister powders to over the counter available powders, and if the big boys have all that chemical science at their disposal, why not +P or +P+ velocities with lower pressure powders?

Tom


------------------
A "Miss" is the ultimate overpenetration!
Banzai is offline  
Old February 22, 2000, 10:31 PM   #2
Ricciardelli
Member
 
Join Date: January 26, 2000
Posts: 57
TINSTAAFL...

"Terminal" characteristics are determined on bullet weight, bullet construction, bullet velocity and bullet form factor.

Velocity is based on pressure.

A decrease in pressure generally causes a decrease in velocity, which causes lower terminal KE.
Ricciardelli is offline  
Old February 23, 2000, 06:25 PM   #3
Cougar
Senior Member
 
Join Date: February 18, 2000
Location: N.E. Ohio
Posts: 637
A +P or +P+ designation is denoting a +Pressure round. For instance, a .38SPL has a max SAAMI pressure of around 16,500psi. A +P has a max pressure of 18-19,000psi.

The reason for using a +P is for higher velocity with a given powder, simple as that. Higher velocity=higher energy. A lot of alloy framed revolvers or pistols are not recommended for use with +P or +P+ ammo.
Cougar is offline  
Old February 23, 2000, 09:10 PM   #4
WESHOOT2
Senior Member
 
Join Date: February 20, 1999
Location: home on the range; Vermont (Caspian country)
Posts: 13,926
+P is a SAAMI-designated pressure level.

+P+ refers to the 9x19 only, and means NO PRESSURE LIMIT.

Whee!!!!!!!!!!!

------------------
"All my ammo is factory ammo"

WESHOOT2 is offline  
Old February 24, 2000, 04:18 AM   #5
Hal
Senior Member
 
Join Date: October 9, 1998
Location: Ohio USA
Posts: 7,377
Banzai,
The only reason I can think of for the big name mfg's to stay with one powder is cost.
If load X uses 4 gr, and load Y uses 6 gr for standard, but 5 gr in load X gives the same velocity as load Y does with 6 gr, then the mfg have saved 1 gr, but are above pressure limits. That 1 gr isn't much of a savings, until you think in terms of millions of rounds.

CAUTION! Load data is max taken from Alliant site, do not exceed!

Example:

Desired velocity=1400 fps
Other components:240gr JSP, .44mag case, primer. ( I know, no +p for a .44, but it's easier to see the difference, and I think you can catch the drift better. 'sides, the data is easier to find)=A fixed constant, ergo the same for both loads.
Choice of powders, at the ( for purpose of illustration) same cost per pound: Bulleseye and 2400
8.9 gr Bulleseye=1200 fps@ 34,700 psi
18.7 gr 2400=1440 fps @ 34,800 psi
A +p, or +p+ loading of Bulleseye can give the same fps (In theory, and for illustration) as the 2400 at a "cost savings" of 9 gr or so of powder. I can make 374 rounds of finished product using 2400, using 18.7 gr,@ 7000 gr per pound(another fixed). Using 8.9 of Bulleseye, I can make 786 rounds, or almost twice as many, for the same cost. If I go over "book", or +p, I can still make a much higher profit, but at the expence of pressures exceeding spec.


[This message has been edited by RAE (edited February 24, 2000).]
Hal is offline  
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 02:43 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
This site and contents, including all posts, Copyright © 1998-2013 S.W.A.T. Magazine
Copyright Complaints: Please direct DMCA Takedown Notices to the registered agent: thefiringline.com
Contact Us
Page generated in 0.07176 seconds with 7 queries