Long Range Hunting Online Magazine


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

Reloading Techniques For Reloading


Reply

More powder with longer c.o.l.

 
LinkBack Thread Tools Display Modes
  #1  
Old 09-16-2013, 05:00 PM
Bronze Member
 
Join Date: Dec 2004
Location: Hegins, Pa.
Posts: 66
More powder with longer c.o.l.

My friend was telling me about the Berger manual stating that you can use more powder in a cartridge if you seat the bullet out further. Here is a copy of the piece.. I never knew this and have been reloading 25 or so years. Thanks for your input on the subject. PaLuke



Effects of Seating Depth / COAL on Pressure and Velocity
SAAMI COAL
Figure 1. When the bullet is seated farther out of the case, there is more volume available for powder. This enables the cartridge to generate higher muzzle velocity with the same pressure.
The primary effect of loading a cartridge long is that it leaves more internal volume inside the cartridge. This extra internal volume has a well known effect; for a given powder charge, there will be less pressure and less velocity produced because of the extra empty space. Another way to look at this is you have to use more powder to achieve the same pressure and velocity when the bullet is seated out long. In fact, the extra powder you can add to a cartridge with the bullet seated long will allow you to achieve greater velocity at the same pressure than a cartridge with a bullet seated short.
When you think about it, it makes good sense. After all, when you seat the bullet out longer and leave more internal case volume for powder, you’re effectively making the cartridge into a bigger cartridge by increasing the size of the combustion chamber.
Reply With Quote
  #2  
Old 09-16-2013, 05:53 PM
Platinum Member
 
Join Date: Dec 2011
Location: S.E. Michigan
Posts: 3,413
Re: More powder with longer c.o.l.

I posted that a month ago in a thread. My jury is out on it however but then I don't load Berger bullets. I just read it online on the Berger site.
__________________
'It's not about me, it's about we'..........
Reply With Quote
  #3  
Old 09-16-2013, 05:57 PM
Bronze Member
 
Join Date: Dec 2004
Location: Hegins, Pa.
Posts: 66
Re: More powder with longer c.o.l.

Sidecarflip, I'll search it to see the responses. I've never came across any info like that and was just checking it out. Thanks for the time and response. PaLuke
Reply With Quote
  #4  
Old 09-16-2013, 06:16 PM
Platinum Member
 
Join Date: Dec 2011
Location: S.E. Michigan
Posts: 3,413
Re: More powder with longer c.o.l.

No issue, I took it with a grain of salt. There is more going on inside a cartridge than just propellant burning. So I considered Berger's comments as loading beyond the maximimum proven load and candidly, I don't want to experiment even though modern receivers have vent holes for such 'experiments' on each side, it would still ruin the firearm.

If I had an old clunker, I might mount it in a Lead sled and use a string to pull the trigger to see what occured but thats about it for me. No old clunkers here, except me.

There is more discourse along with the powder versus jump theory about SAMMI specs and COAL, some of which I can accept, some of which I prefer not to.

I typically jump bullets but I've never increased the load past the loads listed in the respective bullet manufacturers books for the bullet I'm using. Again, I don't load Berger's, except maybe on the grill....oooops, thats burger, not berger...
__________________
'It's not about me, it's about we'..........
Reply With Quote
  #5  
Old 09-16-2013, 07:24 PM
Bronze Member
 
Join Date: Dec 2004
Location: Hegins, Pa.
Posts: 66
Re: More powder with longer c.o.l.

Thanks again. I suggested to him to leave well enough alone.
He shoots a 270 and it groups sub moa with Hornady interlocks.
I'd personally be very leary going over max with any load. Why
chance it. Thanks again.
Reply With Quote
  #6  
Old 09-16-2013, 08:21 PM
Silver Member
 
Join Date: Sep 2012
Location: minco, ok
Posts: 104
Re: More powder with longer c.o.l.

As long as you watch for signs who's to say what's safe I got all the way to 92gr of retumbo in my 338 ultra with 300gr bergers I ended up going back to 90.5gr for accuracy but even that is over book load it was loaded to a col of 4.088 with a custom throat so as for theory your correct however homework must be done and caution exercised
Reply With Quote
  #7  
Old 09-22-2013, 12:00 AM
Silver Member
 
Join Date: Oct 2010
Location: Montana Plains
Posts: 289
Re: More powder with longer c.o.l.

You can increase powder load if you seat a bullet further out than book spec. Been doing this with 9mm Luger to get a powder load 20% or so over book, and 466 foot pounds of energy with a Hornady 115 XTP, which allows 1mm set forward of the bullet. On top of that, I use a popular .44 Magnum and 10mm Auto powder that compresses which slows the initial burn and reduces pressure. The +P 9mm Luger actually operates at 1000 PSI above 10mm Auto pressure. The Lee manual mentions this powder compression trick. Will not give load data as you MUST ascertain that your pistol can tolerate the forward seating and still have .030" bullet jump or therabouts.

You can decrease powder load by seating inward and/or using a magnum primer if you have been using a standard primer.

The point is that loose powder loads perform erratically so you need to get from a nearly full case to a somewhat compressed powder load for consistent performance. Somewhere in that range has always worked best for me.
Reply With Quote
Reply

Bookmarks

Thread Tools
Display Modes


Current Poll
Do you wear hearing protection while hunting?

All times are GMT -5. The time now is 09:26 PM.


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