Large rifle primers in a magnum?

[std7mag]

So i use Federal 215 magnum primers in my 7mm Rem Mag.
I've been hearing about people using the Federal 210 primer.

Suppossed to stabilize ES/DS.

Thoughts?

[disseminator]

While I always use a Magnum Primer myself in the 7RM, I suppose it would depend on your choice of powder and expected operating temperature ultimately.

[Marco Califo]

We are talking about bolt action, right?
Magnum primers are recommended for Ball type Powders (Example H335). They can be harder to ignite than Extruded Powders (example IMR 4064).
Extruded powders are more easily ignited, and are supposed to be very forgiving of powder charge variance. Many extruded powders are temperature insensitive due to additives.
So, it would seem to make sense that you may lower SD/ES using regular non-magnum primers, when using extruded powders, even in a magnum chambering. I do not think that sounds dangerous in any way, and would be interested in your results.

[std7mag]

I'm using RL23, RL26.
So both are extruded powders.

[jmr40]

It won't hurt a thing to try and see. A few years ago when components were hard to find I was running low on magnum primers and substituted Winchester LR primers in my 300 WSM. There was no difference in velocity or accuracy.

[Mobuck]

Using moderate burn rate powders in moderate weather, probably will work fine. Combine slow burn(possibly harder to light due to heavy coatings) with extreme cold and you may see issues.

[Stats Shooter]

Talking with the folks at Speer (Makers of CCI primers), magnum primers are recommended in two applications.

We are talking about bolt action, right?
Magnum primers are recommended for Ball type Powders (Example H335). They can be harder to ignite than Extruded Powders (example IMR 4064).

For safety sake and a guaranteed ignition of ball powders like mentioned in the quote above, Speer recommends using magnum primers. H110 in the 44 mag is another example where the magnum primer is best. In my case I was discussing 58 gr of H335 in my 45-70 and a magnum primer ensured consistent ignition.

The other instance are long columns of powder in my .300win mag or .338 Lapua. I use 80 gr H1000 in my .300wm and 91 in the .338 LM. That's good bit of powder to get burning.

My rule of thumb is: Magnum Primers can be used when they aren't warranted, but not the other way around.

[Marco Califo]

CAUTION: The following post includes loading data beyond or not covered by currently published maximums for this cartridge. USE AT YOUR OWN RISK. Neither the writer, The Firing Line, nor the staff of TFL assume any liability for any damage or injury resulting from use of this information.

@Stats Shooter - You mentioned 45-70. If you search the link below, you will find some load date for 45-70 using WC872 and a magnum primer (No Duplex powder stack needed).

I had not thought about Magnum chamberings and their powder columns. I think magnum primers in "tall powder columns" should yield more consistent results with the more appropriate magnum ignition. That may not "require" magnum primers for extruded powders, but I think magnum primers would give more consistent results.
This reminds me of "during the great shortage" I played around with very slow Ball powder WC872 recovered from 20mm Vulcan pulldowns. I picked up 8lbs of WC872 for $39.99 and 8lbs of WC844 for about $80 from the old Wideners. This led to three Options with the surplus powders.
Source info, albeit scant: http://www.castpics.net/LoadData/Surplus/default.html
!. WC844 is equivalent to and replacement for H335, works fine, barrels get hot quickly. Serviceable for 65 gr and under. Also useful as is in 308.
II. One purpose of the WC872 was to mix it with carefully controlled portions of the faster WC844. In short a 872-50:50-844 mix was useful, predictable. Also steps of mostly 872 and 5 to 45% 844 were tried along the way. Nothing spectacular. But they all went bang and rang the steel plates. I tested these in 223 and only a bit in 308.
III. [Not tested yet] My other purpose for the 872 was as a very inexpensive propellant for 308/7.62, using heavy bullets (180 & +). Ball powder AND VERY SLOW. My research on this lost out to competing priorities, But I have around 300 or 500 220 gr RN. I think these are too heavy for 308 duplex loads and I have been eyeing Savage 30-06's. To set them off, myself and others tried certain things, typically a 3 gr. booster of Unique, over the primer and under the column of cannon powder. That was actually the point of my ramble: With a very slow ball powder, yes, use magnum primers, but also be aware there are other potential ignition boosters. I am thinking I can get 2300-ish results for 30-06 with the 220 gr JRN projectiles.

[mikld]

This is one situation where a chronograph works well for a home reloader. Load some ammo with both primers and run them over a chrony and see which gives the most consistent velocities (lowest Standard Deviation)..

[T. O'Heir]

Magnum primers have nothing whatever to do with the cartridge. Especially it's name. They're about the powder used and nothing more. Mind you, in places like Central Pennsyltucky, where it has been known to get seriously cold, magnum primers can help ignite powders that don't like the cold.
"...Magnum primers are recommended for Ball type Powders..." They have nothing to do with the shape of the granules either.
"...H110 in the 44..." Not according to Hodgdon. Their site finally got fixed for some cartridges and they stopped saying magnum primers for magnum named cartridges, but hot for non-magnum named cartridges. Their H110 .44 Mag loads were developed with regular primers. Daft twits still show magnum primers for 7mm Rem Mag and powders that absolutely no not require 'em. Like IMR4064.

[Stats Shooter]

Magnum primers have nothing whatever to do with the cartridge. Especially it's name. They're about the powder used and nothing more. Mind you, in places like Central Pennsyltucky, where it has been known to get seriously cold, magnum primers can help ignite powders that don't like the cold.
"...Magnum primers are recommended for Ball type Powders..." They have nothing to do with the shape of the granules either.
"...H110 in the 44..." Not according to Hodgdon. Their site finally got fixed for some cartridges and they stopped saying magnum primers for magnum named cartridges, but hot for non-magnum named cartridges. Their H110 .44 Mag loads were developed with regular primers. Daft twits still show magnum primers for 7mm Rem Mag and powders that absolutely no not require 'em. Like IMR4064.

First of all you contradict yourself here

They're about the powder used and nothing more

Then you say

They have nothing to do with the shape of the granules either

The shape of the granules has a lot to do with the type.

H110 in the 44..." Not according to Hodgdon

What will work and what works best are not the same questions. Ignition in general vs most consistent ignition giving best results are distinctions we are making here.