Magnum primers vs standard

[hlq]

I stopped at five gun shops this weekend looking for standard primers. All but one was out but they all had magnum primers. How much difference is there between the two? In a pinch can I use magnums and if I can do I need to adjust any of the other components?

A couple of examples:

1. Let's say I'm loading my 45 acp with a 185gr jacketed bullet and 5.7gr of W231. How much difference will a mag primer make?

2. I'm loading 223 with a 55gr jacketed bullet and 26gr of Varget. Same question.

thanks,
hlq

 

[NCsmitty]

DO NOT switch to magnum primers with established loads. I suggest going back to a starting load if you pursue this switch.
There is no doubt that magnum primers will increase pressures over standard primers. There are several articles that I have read that corroborate this issue. How much? It varies with several factors.
I recommend staying with the known loads and your standard primers. Someone will have them available.

NCsmitty

 

[jcwit]

+1 Work up a new load

 

[Shoney]

When I first started experimenting with primer substitution, a CCI engineer told me to reduce established loads by 5% and work up.

 

[hlq]

When I first started experimenting with primer substitution, a CCI engineer told me to reduce established loads by 5% and work up.

Thanks, that's good information.
hlq

 

[rockhound758]

Quick followup question (and I +1 all the above by the way)...

Hornady's manual (I believe...don't have it in front of me) states use of standard primers for the 44 mag but also lists several slower vs. faster powders for use in loads. Powder burn rate aside, is it fair to assume that standard primers are enough for the (relatively) small volume of a .44 mag cartridge? So choice of primer (in the context of powder burn rate) is more an issue for larger (e.g., rifle) cases? Just curious.

 

[cliffy]

Slow Powder - Magnum Primer

Taking .223 Remington as a standard example, the slower the burn, the crisper the primer required. X-Terminator, H335 and RL-10x, the most potent .223 Remington powders, benefit from Magnum Primers. Such is probably true throughout the caliber range. cliffy

 

[evan price]

Truthfully, if you are not loading up near maximums you should not have a problem, however always back off and work up again is the rule in reloading. I try to always use Magnum primers with .223 or anything that goes in a gas gun. As far as in your .45, Winchesters are for a Magnum or Standard application, and from my experience they work fine in both. I've used Magnums for nonMagnum applications and couldn't tell a difference.

 

[clugnut]

regular primers to magnum

I called cci about this a few years ago and kevin said it was not nessasary to do anything. The magnum is a little hotter, but does not add any pressure to the load. And i was talking about bullseye in 357 cases i allready had the primers in for h110 heavy loads. The mag primer is for cold weather and to get slow powder ignited.
Seriously, clugnut
ps I have been reloading since 1970 and I havent had any problems.

 

[ArchAngelCD]

rockhound758,
By any chance were those .44 Magnum rounds charges with 2400? Magnum primers are required for hard to ignite powders like H110/W296. When loading 2400 they aren't required because 2400 isn't hard to ignite. Also like said above, in very cold conditions you might need a Magnum primer to insure proper ignition and burn, especially in rifle rounds using temperature sensitive powders.

clugnut,
Welcome to the forum...

 

[jjohnson]

Slow Powders?

That's interesting.

I would think that, lawyers doing what lawyers do, if there were a significant risk to using magnum primers in non-magnum cartridges, there would be a BIG statement on each primer package warning you to not do this.

That's a guess, take it for what it is.

Others have cautioned to NOT start with top end loads when introducing magnum primers, and to watch pressure signs carefully. That sounds like good advice.

It does seem logical that magnum primers might be worth trying for slower powders (like Blue Dot) that usually don't finish burning completely before the bullet leaves the muzzle.

I just may give that a try and chronograph the standard vs magnum primed loads. If the magnum primed loads wind up going a little faster, maybe this isn't a bad idea.

Mind you, the only cartridge I'm pondering using for a test of this kind are .38 Specials fired in .357 Mag firearms - where moderately higher pressures would still put me way under the limit. And I am NOT loading 38 brass with 357 charges.

 

[NCsmitty]

Here's a little info that I found on another site.
If you Google, standard primers versus magnum primers, you'll get this info.

Here is a short summary of the A-Square test of primers in the Remington 7mm Mag. as published in "Handloader" magazine.

160 grain Sierra boat-tail, 66.0 grains of Hodgdon H-4831 and Winchester cases.


Winchester WLRM (magnum) 3045 fps, 67,600 psi

Winchester WLR (standard) 3024 fps, 64,400 psi

Federal 215 (magnum) 3036 fps, 61,400 psi

CCI 250 (magnum) 3039 fps, 61,500 psi

Remington 9½ M (magnum) 3041 fps, 59,300 psi

CCI 200 (standard) 3011 fps, 54,800 psi

NCsmitty

 

[Iheartguns]

What about the Winchester WLP primers which are "For standard or magnum cartridges?"

 

[NCsmitty]

Yes, it's strange that Winchester makes small regular pistol and small magnum pistol primers but only make WLP for large pistol.

I only use CCI primers in all my brass and have for the last 40+years.
I use Winchester 209's in my shotshell loads.

NCsmitty

 

[rockhound758]

ArchAngel:

I think all the loads listed for the .44 mag in the Hornaday's 7th edition specified a standard primer, regardless of powder. Haven't checked any other sources. I think before I knew better (when I was first starting out) I used magnum primers pretty much all the time. In any case (no pun intended) it sounds like just be careful and watch for pressure signs and work up again if you do want to try and switch with the faster powders.

 

[ArchAngelCD]

rockhound758,
The guidelines you just laid out are good advice for all reloading. If you follow that mindset all the time you will never have a problem.

 

[Shoney]

According to the A-Square test of standard primer vs. magnum primers in the Remington 7mm Mag, you get roughly a 1% increase in velocity with a 20-23% increase in pressure.

Considering that SAAMI spec for the 7Mag is 61,000 psi, 3 of the primers tested put the pressures just below or just over max, and two were significantly over max. I'd think that tells a lot.

 

[ArchAngelCD]

Shoney,
There's a big difference between a small charge of 5.7gr W231 used in a handgun round and 60gr to 70gr of a slow burning rifle powder used in a 7mm Mag round. While I'm sure you can get a large pressure spike from the mentioned rifle charge I highly doubt you will get a 20+% pressure increase in the .45 Auto case using W231.

 

[physicist]

magnum primers

I sent the following question to Accurate Arms.


Regarding 9mm, .45ACP, .38 , and .357 . When is it permissible to use small pistol magnum primers instead of small pistol primers? I seem to be having problems getting small pistol primers (CCI), but have no problems getting small pistol magnum (Winchester and CCI) primers.


Here's their reply:

As long as you begin at the minimum START and develop your loads in 2% increments all will be fine. The normal -10% will amply compensate if there is to be a difference.

 

[redneck2]

Considering that SAAMI spec for the 7Mag is 61,000 psi, 3 of the primers tested put the pressures just below or just over max, and two were significantly over max. I'd think that tells a lot.

Yeah, I'm just not sure what. The Rem Magnum primer gave 59,300 and WW std gave 64,400 and WW mag 67,600. WW standard is higher than any other brand of magnum.