Magnum primers give less speed than regular ones ?

[hexades1]

In my .284 Win I noticed that with otherwise the same load (180 Berger VLD, 58,0 greins of N560, C.O.L 80,0mm, Lapua brass) I got 4 m/s less speed with Fed215 magnum primer than with Fed210. With Fed210 898 m/s and with Fed215 894m/s at +18C.

This goes against the common logic but I suspect the magnum primer with +100% powder filling pushes the bullet out of the case before the powder starts to burn propewrly. The Fed210 apparently is less powerfull and can not push the bullet out and therefore the powder starts burning faster and at a somewhat higher pressure.

What do you think is happening ?

Does anyone use Fed215 for their .284 Win loads ? I plan on using Fed210 in this rifle in future.

 

[Mudcat-NC]

Re: Magnum primers give less speed than regular ones ?

Thats not unsual, though I am not sure why it is the case.

 

[Jered Joplin]

Re: Magnum primers give less speed than regular ones ?

You are correct on the burn rate. Just food for thought. If you aren't burning 65g or more of powder you don't need a magnum primer.

 

[Graham]

Re: Magnum primers give less speed than regular ones ?

Try CCI BR2's for the .284 with Lapua brass.

 

[LR-WSM]

Re: Magnum primers give less speed than regular ones ?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: JJoplin</div><div class="ubbcode-body">You are correct on the burn rate. Just food for thought. If you aren't burning 65g or more of powder you don't need a magnum primer. </div></div>

I was taught that magnum primers were also to be used with high density powders such as ball and SSC as there was a lack of sufficient air space between granuals for a standard primer to get the job done evenly. Standard length extruded powders can be ignighted well with either as there is sufficient air space for the primer to light the load uniformly.

 

[Greg Langelius *]

Re: Magnum primers give less speed than regular ones ?

Piece of advice. Do your load developement with Standard, not Match, primers. When you have your load, try the Match primer from the same maker. See what it buys you. You may find that <span style="font-style: italic">your application</span> can get by nicely without Match primers. For ball powders, especially Winchester, try Winchester primers. They are formulated specifically to ignite powders with stubborn deterrent coatings. If memory serves, Win does not make a Match primer. That's got to bear some very basic message in there somewhere.

Greg

 

[FNARSHOOTER]

Re: Magnum primers give less speed than regular ones ?

Match primers are softer than standard primers. I have found they are of the same strenght just require less energy fom the pin to ignite. Mill spec primers are harder that standard and require more energy to ignite and are of the same strenght as standard. Winchester only has one primer they claim to be for standard or Magnum apps.
Scot

 

[Jered Joplin]

Re: Magnum primers give less speed than regular ones ?

Without a doubt the only difference between a 210 and 210M is the fact that the M is inspected twice. I was given this info from a Federal employee. I didn't see it in person.

 

[bohem]

Re: Magnum primers give less speed than regular ones ?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: JJoplin</div><div class="ubbcode-body">You are correct on the burn rate. Just food for thought. If you aren't burning 65g or more of powder you don't need a magnum primer. </div></div>

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: JJoplin</div><div class="ubbcode-body">Without a doubt the only difference between a 210 and 210M is the fact that the M is inspected twice. I was given this info from a Federal employee. I didn't see it in person.</div></div>

I've heard this and read this for several manufacturers.

For CCI and Wolf I've been told by some reputable sources (including CCI's tech support) that the difference is just a harder primer cup on the mag primers.

If the internal composition of the primer is identical and you're just getting a harder cup then why does it matter to use a regular vs. mag primer? I've heard Tom Sarver say that if you're not shooting 90gr or more of powder then there's no reason to use a mag primer.

I'm using Wolf primers in a couple of rifles with great success. I have been using the mag primers because I get less flattening and cratering from the same load. This tends to support the harder cup idea. I see no difference in velocity from the primer change on identical loads, but I do have the capability to get another 1/2 gr of powder into my 6.5-06 and 30-06 loads. This increase gets me to a higher node to shoot similar repeatability with, and I have tended to push the cases harder and run higher velocities.

Until I see the extractor groove grow I push on the loads, my 6.5-06 (Rem 700) grows the grooves before I get ejector smears, my 30-06 (M98) grows them just shy of flattening out the headstamp markings on the case head.

I'm not trying to be argumentative, I'm trying to understand how the same composition and same charge of material in the primer is supposed to make a difference in how much charge weight you're shooting them with.

What's to say it's not 65gr or 90gr, what's not to say it's just the operating pressure that you're running?

 

[Fred_C_Dobbs]

Re: Magnum primers give less speed than regular ones ?

TA, you might be on to something with the compressed load. Maybe it is unseating the bullet earlier in the process than burning powder alone would have. And I can think of an additional possibility.

Maybe the magnum primer is crushing some of those (already compressed) powder granules. Crushing exposes uncoated surface to flame, which alters the pressure curve.

Looking at your load's properties in QuickLoad, it appears that N560 is formulated so that the rate of production of evolved gasses continues to increase until well after PMax. My guess is that this would boost MV, especially with your load's relatively low (QL-predicted) chamber pressure (3336 bar/48.4k psi).

I'm thinking maybe the magnum primer crushes some of the powder, which increases its burn rate, which means "Z1" -- the point at which evolution of gasses ceases to accelerate -- occurs earlier than Vihtavuori intended and closer to PMax.

Or maybe it's a bit of both. Or maybe "olen idioott."

 

[FNARSHOOTER]

Re: Magnum primers give less speed than regular ones ?

When they started using 209 primers for inline muzzle loaders they found the force of the primer was pushing the load before lighting it they now have special 209 just for this. Sound like the same thing is happening in your case.
Scot