Long Range Hunting Online Magazine


Go Back   Long Range Hunting Online Magazine > Rifles, Reloading, Optics, Equipment > Reloading

Reloading Techniques For Reloading


Reply

New brass - different velocities than fire formed?

 
LinkBack Thread Tools Display Modes
  #1  
Old 06-16-2010, 12:46 PM
tlk tlk is offline
Silver Member
 
Join Date: Apr 2008
Posts: 238
New brass - different velocities than fire formed?

Lapua 30-06 brass, 4x shot, cleaned with ultrasonic cleaner (CLEAN inside), all the prep work done and all brass is exactly the same. Avg = 2952 fps.

SAME brass, same lot, never fired, prepped the EXACT same way, avg = 2990 fps.

What gives? Need some light here...


Thanks.
Reply With Quote
  #2  
Old 06-16-2010, 04:56 PM
Platinum Member
 
Join Date: Aug 2003
Location: NC, oceanfront
Posts: 3,364
Re: New brass - different velocities than fire formed?

New brass has yet to blow out to fireformed dimensions. So it has less capacity.
You put the same load in a smaller case and pressure goes up, velocity goes up.
Reply With Quote
  #3  
Old 06-16-2010, 06:02 PM
tlk tlk is offline
Silver Member
 
Join Date: Apr 2008
Posts: 238
Re: New brass - different velocities than fire formed?

OK cool, thanks.

The other conclusion there is that the bullet leaves before the brass fully expands to the chamber, correct?
Reply With Quote
  #4  
Old 06-16-2010, 06:33 PM
Platinum Member
 
Join Date: Aug 2003
Location: NC, oceanfront
Posts: 3,364
Re: New brass - different velocities than fire formed?

No reason to...
Reply With Quote
  #5  
Old 06-17-2010, 09:59 AM
tlk tlk is offline
Silver Member
 
Join Date: Apr 2008
Posts: 238
Re: New brass - different velocities than fire formed?

Mike, I have NO idea how to read that last statement - can you explain?
Reply With Quote
  #6  
Old 06-17-2010, 12:03 PM
Platinum Member
 
Join Date: Aug 2003
Location: NC, oceanfront
Posts: 3,364
Re: New brass - different velocities than fire formed?

Enough of that powder is lit & reacting to it's confinement, before ANYTHING moves or changes, that the affect in discussion barely relates to further downstream timing.
Yes the brass expands quickly, but much of the powder's burn rate has already been altered by it's tighter confinement. So unless something unusal downstream counters this, all will be influenced by it.

Given this, it makes absolutely no sense to rely on brass that isn't fully fireformed & stable in dimensions. Atleast, not for LR accuracy..
And you bring a good example, which is supporting of this position.

To heal this, many FL size brass -everytime.
This is rediculous in my view, as dimesions can be managed without all the side affects.
Fireforming(2-3 reloads) followed by minimal sizing is good enough.
Reply With Quote
  #7  
Old 09-11-2014, 04:55 PM
Junior Member
 
Join Date: Jan 2013
Posts: 19
Re: New brass - different velocities than fire formed?

I've been working up an elk load for this fall in my 300 Win Mag and have decided on 73 gr. H4831sc behind 190 ABLR's velocity is around 2850 in used brass. Recently I've been shooting this load in new Nosler brass and my velocity is off between 100 and 150 fps and accuracy is about 1.5" at 100 yards versus under 1" with used brass.

I've talked with several knowledgeable reloaders at my gun club and they say it stands to reason since new case expansion will reduce pressure to some extent and therefore drive the bullet just a bit slower.

I intend to use the once fired cases for my hunt.

Any thoughts on this?

Don
Reply With Quote
Reply

Bookmarks

Thread Tools
Display Modes


Similar Threads for: New brass - different velocities than fire formed?
Thread Thread Starter Forum Replies Last Post
Virgin brass vs. fire formed KQguy Reloading 34 08-06-2012 10:15 PM
Norma 30 HART Brass Fire Formed ERIC Reloading Equipment and Components 1 07-02-2009 08:38 PM
Fire Formed Brass? samson The Basics, Starting Out 7 03-22-2009 11:03 PM
Soot on fire formed brass, but not on new brass- 7RM?? Andy W Reloading 2 11-04-2006 10:30 AM
Wont chamber fire formed brass? daveosok Rifles, Bullets, Barrels & Ballistics 9 08-14-2002 10:10 AM


All times are GMT -5. The time now is 11:30 PM.


Powered by vBulletin ©2000 - 2014, Jelsoft Enterprises Ltd.
Content Management Powered by vBadvanced CMPS
All content ©2010-2014 Long Range Hunting, LLC