Small rifle primers vs SR Magnum primers

[mugsie]

I have done hours of reading and research on this question. What prompted it was the fact that nowhere around here can I find SRM primers. I'm shooting 25 grains of H335 under a 53 grain FB bullet.in the past using a ball powder, I always used a magnum primer. Well now they are as scarce as hens teeth!

So I loaded up 13 rounds with the last 13 magnum primers, then another 13 with standard primers. Both were CCI primers. OAL, brass, etc were all the same. Today I went to the range and shot them both, couple of SRM's then standard, then SRM's etc.

The results surprised me. The standard primers grouped tighter, and more consistent than the magnum primers. I don't know if these results would be the same using a larger case, such as a .308 family, but in the 223 family I know going forward I will be using standard rifle primers instead of magnum.

I also realize manufacturers tell us that for ball powders we need the extra oomph to get it all lit properly, but emperical results do not support that statement. I'm tending to believe the majority opinions out there that it truly is marketing hype to drive more sales and greater profits.

Comments?

 

[mugsie]

Mods, maybe this should go in the hand loading section? Your choice.
Thanks....

 

[rodregier]

Action type?

Powder type?

Keep in mind that ignition becomes more challenging as the ambient temperature drops. You may have a load that works ok above freezing, but is intermittent with much colder temperatures. Thinner cups in some of the non-magnum primers also have the increased prospect of primer piercing, which is bad news for bolt faces and firing pins if nothing worse happens.

 

[Rule3]

Hodgdon does not recommend using a Magnum primer in their data, so I guess I do not see an issue??

Their data was tested with a regular Winchester SR primer

http://data.hodgdon.com/cartridge_load.asp

 

[mugsie]

Rule 3,

That's interesting that you mention that about the SR primer in Hodgdon's data. I had used this recipe for years, but with magnum primers, which came out of a Speer loading manual. Speer recommends a magnum primer whenever a ball powder is being used. They specifically highlight it in the manual on the individual loads in order to stress that fact.

Anyway, emperical data demonstrated quite clearly today that I no longer need the magnum primers, which is a very good thing. Now I can go out and stock up on more SR primers to keep the ones I already have on hand company.

Thanks for pointing that out to me. I usually always use the Hodgdon site too, but never thought to print the recipe out to look at the primer selection.

Stay well and shoot straight.....

 

[rodregier]

Reloading manuals are rather like watches.

If you have one watch you know what time it is, with two watches you're not sure

 

[Rule3]

I have never used a magnum primer in 223

Speer #14 calls for a Mag primer or the CCI 41 for H335 and few other powders.

Hornady #8 calls for a regular primer, so go figure?

Some data wants the 41 primer for AR 15's Hornady does not. I use Hornady data more than any others. The make more bullets than Speer.

Kinda like Hodgdon dat for any magnum pistol load uses a Mag pistol primer even though the powder does not require it. Like HP 38 in a 357Mag.

 

[mtrmn]

I have used my supply down to where I only use CCI 34's or 41's exclusively. ("military primers") Both are "magnum" strength according to CCI's website.