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Warnberg Rookie Member
Joined: Nov 28, 2010 Posts: 17 Location: Tampa, Florida
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Posted: Wed Nov 02, 2011 5:58 pm Post subject: magnum v regular primers |
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/I'm probably going to open a can of worms here but here it goes. If I took an identical load one with a regular primer one with a magnum primer what difference if any will I observe?
Example:
Ruger 204, berger 40 gr BT, 26gr Varget, CCI Primer
Ruger 204, berger 40 gr BT, 26gr Varget, CCI magnum Primer
Would I see any difference in FPS or group between these two loads?
What if the load was a partially compressed load, would there be a differance then?
I'm just trying to figure out what a magnum primer does that a regular primer doesn't do.
Thanks
Dave
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Dawgdad Super Member
Joined: Feb 08, 2006 Posts: 1065 Location: On the Prairie
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Posted: Wed Nov 02, 2011 6:18 pm Post subject: Re: magnum v regular primers |
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It is one of the great things about reloading you can try it and see. Magnum primers are usually for larger amounts of slower powders but the increased briscillance of the magnum primer can improve ignition in normal loads... or.. it can rasie the pressure and increase the SD and ES of a load.. or.. it can have no effect at all.
Run 10 of each over the chrono and measure the groups and see what you get.
_________________ Alcohol, Tobacco and Firearms should be a convenience store, not a government agency... |
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Vince Site Admin
Joined: May 25, 2005 Posts: 15725 Location: Brisbane AUSTRALIA
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gelandangan Super Member
Joined: May 07, 2006 Posts: 6401 Location: Sydney Australia
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Posted: Thu Nov 03, 2011 12:55 am Post subject: Re: magnum v regular primers |
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In my 300 Whisper, magnum primers gave consistently lower MV than standard primers.
I am sure I have checked and double checked my primers, I have also purchased a fresh box from another supplier just to try.
It must be because of the low charge amount.
_________________ A straight line is the shortest distance between two points.
A smile is the shortest distance between two people.
Do - Not try!
gelandangan.weebly.com/ |
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stovepipe Super Member
Joined: Sep 25, 2008 Posts: 4877 Location: Pine, Az.
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Posted: Thu Nov 03, 2011 9:34 am Post subject: Re: magnum v regular primers |
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What's the RECIPE call for?
204's a pretty damn zippy round. Doubt I'd wanna do anything to alter the presure curve on that. Esp on a "partially compressed" load (what the heck is that?), as if it comes out of compression during settling during transport you now have a BOMB. I avoid compressed loads like the plague. Way too risky and inconsistent. If you need more room find a powder with the same speed and and a lower VD.
If the recipe calls for a mag primer, use it, with a START load, go from there. Varget's a medium speed powder and @ 40gr ya dont even need a mag primer.
Start loading long colums of 68gr+ of 4831 or slower? Then you can use a mag primer IF the recipe says too. Mag primers are wild cards. They can alter pressure curves and send things over the top faster than the chamber can handle them. It's dont take muhc @ 50-60k PSI.
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MacD Super Member
Joined: Apr 08, 2011 Posts: 1052 Location: Canada
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Posted: Thu Nov 03, 2011 10:05 am Post subject: Re: magnum v regular primers |
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My only experience is with loading regular versus magnum is for the 308. Using 43.5 grains of Varget and a 168 grain bullet the magnum primers gave me a higher average velocity and a lower deviation. I will check my records this PM when I get off work to get the exact numbers. Their was a slight improvement in grouping but I can't say it was the primers. This is a medium load and not compressed.
Added: CCI 200 versus CCI 250
_________________ La a'Blair s'math n Cairdean
(Friends are good on the day of battle)
Last edited by MacD on Thu Nov 03, 2011 10:19 am; edited 1 time in total |
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chambered221 Super Member
Joined: Aug 17, 2007 Posts: 3455 Location: Lost for good !!!
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Posted: Thu Nov 03, 2011 10:09 am Post subject: Re: magnum v regular primers |
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The primary idea behind magnum primers is to provide a hotter ignition for larger amounts of powder. Cold climates can also benefit from the use of a mag primer.
With that said.......... they are like any other component that can be substituted and experimented with !!!
Just remember......... they are not universal......they can not be interchanged freely !!!
They vary in strength from one manufacturer to another.
It's possible that ones standard is just as hot as an others mag.
Personally I've never seen the need to use them when not called for, but others have found them to be beneficial.
_________________ Ask as many people needed, sooner or later your question will be answered the way you want it answered !!!
A free people ought not only to be armed and disciplined, but they should have sufficient arms and ammunition to maintain a status of independence from any who might attempt to abuse them, which would include their own government.
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chambered221 Super Member
Joined: Aug 17, 2007 Posts: 3455 Location: Lost for good !!!
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Posted: Thu Nov 03, 2011 10:12 am Post subject: Re: magnum v regular primers |
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gelandangan wrote: |
In my 300 Whisper, magnum primers gave consistently lower MV than standard primers. |
Were they the same manufacture or different brands ???
_________________ Ask as many people needed, sooner or later your question will be answered the way you want it answered !!!
A free people ought not only to be armed and disciplined, but they should have sufficient arms and ammunition to maintain a status of independence from any who might attempt to abuse them, which would include their own government.
~George Washington |
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Aloysius Super Member
Joined: Nov 03, 2009 Posts: 2440 Location: B., Belgium
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Posted: Thu Nov 03, 2011 10:47 am Post subject: Re: magnum v regular primers |
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magnum versus regular...
and what about match primers?
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Ominivision1 Super Member
Joined: Sep 20, 2010 Posts: 2984 Location: Iowa
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Posted: Thu Nov 03, 2011 11:10 am Post subject: Re: magnum v regular primers |
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I think bench-rest and match primers are closer to magnum primers, plus they are suppose to be more consistent in the cup paste mixture.
Geland:
When you tried those magnum primers, were they on the same day as you tried the standard primers? Weather has a lot to do with overall performance.
_________________ Regards
Limitations are but boundaries created inside our minds. |
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TRBLSHTR Super Member
Joined: Mar 23, 2007 Posts: 1071 Location: Lower 48's-left coast(near portlandia)
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stovepipe Super Member
Joined: Sep 25, 2008 Posts: 4877 Location: Pine, Az.
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Posted: Thu Nov 03, 2011 12:13 pm Post subject: Re: magnum v regular primers |
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Cuz you use them in connection with BR reloading recipes and methods and components. For standard target and hunting loads dont even bother. Just buy standard, easy to find primers and get back on with life.
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MacD Super Member
Joined: Apr 08, 2011 Posts: 1052 Location: Canada
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Posted: Thu Nov 03, 2011 4:18 pm Post subject: Re: magnum v regular primers |
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Checked my records
Bullet: 168 Grain Hornady A-Max
43.5 Grains Varget
O.A.L. 2.800
New Winchester brass full length sized.
Range was 50 meters.
5 shots each
CCI 200 LR = Avg 2468 FPS Spread 2437-2506 Avg Group .44 **
CCI 250 LR = Avg 2536 FPS Spread 2520-2554 Avg Group .31
** I dropped two bad shots for grouping as I definitely pulled them. The guy next to me was firing some magnum "shoulder cannon" and my timing was off with respect to trigger let off. Trigger was dialed down to just over 1 pound. With these included Avg. Group was .91.
Both shot the same afternoon, same rifle over the same chronograph placed at the same location. The barrel was fouled and warm for each shot string.
My rifle is 1 in 12 with a 22" barrel. My theory is that the magnum primer gets the bullet moving faster which optimizes the potential of the shorter barrel as less propulsive power is lost to muzzle blast. It would be interesting to repeat this with 24-26 inch barrels to compare the FPS increase, if any, the magnum primer provides. On the safety side, if my theory is correct, this translates into a higher peak pressure and a reason not to try this with a maximum or near maximum load. Maximum for this bullet/powder combination is 46.0 grains (Hodgdon reloading site).
_________________ La a'Blair s'math n Cairdean
(Friends are good on the day of battle) |
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inthedark Super Member
Joined: Jan 31, 2011 Posts: 917 Location: Ontario
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Posted: Thu Nov 03, 2011 6:38 pm Post subject: Re: magnum v regular primers |
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Hey MacD
I use magum primers in both my 22-250 and 308 loads WHEN I am hunting in 0 degree F or below weather. I have found that using the magum primers in warm weather throws my accuracy right out the window. And as I am in brisk old Saskatchewan, I have had plenty of experience with the benefits of mag primers.
_________________ Chimo
Ron
War is sweet to those who have no experience of it, but the experienced man trembles exceedingly at heart on its approach - Pindar 518-438 BC
Be Copy now of Men of Grosser Blood and TEACH THEM HOW TO WAR |
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MacD Super Member
Joined: Apr 08, 2011 Posts: 1052 Location: Canada
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Posted: Thu Nov 03, 2011 7:44 pm Post subject: Re: magnum v regular primers |
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I did winter survival training 40 miles east of Churchill Manitoba in March. I made the mistake of grabbing my 7.62 mag in my outside pocket with my finger tip open gloves and it stuck to my fingers. It was so cold it felt like a burn. Those Valcartier Industries rounds fired every time but the FN's sometimes just froze after a few mags. Now from what I have heard Manitoba is tropical compared to Saskatchewan.
_________________ La a'Blair s'math n Cairdean
(Friends are good on the day of battle) |
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