The Firing Line Forums

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

Reply
 
Thread Tools Search this Thread
Old February 13, 2017, 08:02 AM   #1
irobro
Junior Member
 
Join Date: February 1, 2012
Posts: 9
Potential Problem: 45 Auto, Unique Powder, 230 gr Bullet

I have sent several emails to Alliant Powder asking for comment but have not received a reply. The Alliant Reloaders Guide boldy warns readers not to exceed the charge weights printed in the guide but I'm having trouble deciding which recipe to believe. I would appreciate comments from forum readers. My email to them:
It appears there may be an error on your website Reloader's Guide. The three copper 230gr bullets that you provide recipe's for have charge weights that vary widely: 6.5, 6.0 and 7.3 grains respectively. That's a 20% variance with jacketed hollow point the lowest at 6.0 grains, and a copper plated bullet the highest at 7.3 grains. Logic says there is something significantly wrong. Please comment.
irobro is offline  
Old February 13, 2017, 09:17 AM   #2
huntinaz
Senior Member
 
Join Date: September 21, 2010
Location: az
Posts: 1,294
Lot to consider besides just weight. Different shape, different bearing surfaces, different allow or plating vs jacketed etc mean different pressures and charges.
__________________
"When there’s lead in the air, there’s hope in the heart”- Hunter’s Proverb
"Feed me, or feed me to something. I just want to be part of the food chain." -Al Bundy
huntinaz is offline  
Old February 13, 2017, 11:55 AM   #3
Nick_C_S
Senior Member
 
Join Date: March 21, 2013
Location: Taxifornia
Posts: 4,898
A 230 grain bullet is not just any 230 grain bullet.

One huge difference can be how deep the bullet sits inside the case. This reduces the internal volume available for propellant. In general, the less internal volume, the faster the propellant's burn rate - i.e. more pressure.

Speer #14 has separate data for their 230 round nose, compared to their other 230 profiles.

Whenever I get a new bullet, I always take and record their measurements. Most importantly, the dimension of how deep it sits in the case. For instance, with 357 Mag, Sierra's 158 JSP sits .345" deep in the case; Hornady's 158 XTP sits .370" deep. That's 25-thousandths difference. If I do a work up using a Sierra bullet, I can expect considerably more pressure if I simply switch over to a Hornady XTP; and doing so is ill-advised. A reduction in charge would be in order.
__________________
Gun control laws benefit only criminals and politicians - but then, I repeat myself.
Life Member, National Rifle Association
Nick_C_S is offline  
Old February 13, 2017, 12:24 PM   #4
rg1
Senior Member
 
Join Date: November 6, 2001
Posts: 1,081
I've loaded several different 230 gr. bullets in 45 ACP, plated, jacketed HP and RN, and one lead 230 gr. In all I see 6.0-6.1 grains of Unique to be a good reliable load. Highest charge for me has been 6.5 grains and I would not go higher with any 230 gr. bullet I reload. Remington's 230 Golden Saber, a brass jacketed HP gets a little more powder to get the same velocities due to it's bearing surface shape. I consult a lot of data sources and do not use data that's higher than the norm. Be very careful exceeding 6.5-6.7 grains with any 230 gr. bullet and a lot less hammering on your pistol and brass if you keep charges near 6.0 grains of Unique. Alliant data used to be more reliable for various bullets especially when they were Hercules. Now most of their data is for Gold Dots and TMJ which often doesn't relate to other bullets. I don't use Speer data unless shooting their bullets, just me.

Last edited by rg1; February 13, 2017 at 12:31 PM.
rg1 is offline  
Old February 13, 2017, 12:32 PM   #5
Unclenick
Staff
 
Join Date: March 4, 2005
Location: Ohio
Posts: 16,410
Yes to Nick's information!


Irobro,

Constant charge with bullet weight depends on the bullets all having the same seating depth in the case. But many of the hollow point designs have such blunt nose forms that they won't feed properly when they are seated out to the maximum COL for a round nose bullet. So they seat them deeper. Powder charge has to be reduced some so doing that to avoids excessive pressure.

The other factor is bullet hardness. A plated bullet, like a Gold Dot or a Ranier or a Berry's plated bullet offers less rifling engraving resistance, so they produce lower start pressures. For that reason the powder doesn't burn as fast early in the firing event and the bullet is further down the barrel when the pressure peaks. The additional space behind the bullet due to its moving further forward¹ means the powder is burning in a larger volume. This is why the plated bullet loads call for more powder².


¹The powder burning space increasing because of the bullet moving forward is called expansion.

²With more expansion you need more gas to achieve a given pressure, and it takes more powder to make that additional gas.
__________________
Gunsite Orange Hat Family Member
CMP Certified GSM Master Instructor
NRA Certified Rifle Instructor
NRA Benefactor Member and Golden Eagle
Unclenick is offline  
Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search

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 10:30 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2019, vBulletin Solutions, Inc.
This site and contents, including all posts, Copyright © 1998-2018 S.W.A.T. Magazine
Copyright Complaints: Please direct DMCA Takedown Notices to the registered agent: thefiringline.com
Contact Us
Page generated in 0.05205 seconds with 8 queries