Chris Brines

Just realized that the 400 primers I picked up a few days ago to load my 9mm's and 40 S&W's with..are magnum primers. (CCI Small Magnum Primers)

Just wondering are these safe to use for non magnum calibers? (9 and 40 specifically, obviously)

I'm loading 9mm 115 grain FMJ RN's from Precision Delta, using Hogdon Titegroup. I'd say I'm loading pretty close to the middle of the recommended charge of 4.3 to 4.8 grains. Mine are about 4.5-4.6

To be shot in Glocks.

Spike12

The reloading book you're using will specify is a particular load requires magnum or regular primers.

Military loads (7.62 & 5.56 NATO) assume magnum primers.

Chris Brines

Yeah, it calls for regular primers. I grabbed CCI Magnum Small Pistol Primers, No. 550, by mistake. I'm just wondering if magnum primers can be safely (and effectively) substituted for regular ones, if it is not recommended, or if it is a BIG "no no".

Iowegan

Chris Brines, At best it's risky with the two cartridges you load. Both the 9mm and 40 S&W run pressures in the 35,000 psi range so even with reduced powder charges, magnum primers may put you well over the limit. In low pressure cartridges like a 38 Special, reducing the powder charge by a half grain will compensate for the extra mag primer power but in my opinion, I wouldn't attempt this with a 9mm or 40 S&W and especially with faster burning powder like Titegroup.

Chris Brines

Ok thanks...I'll just save it for my next round of 357 magnums....last time I used Unique for those....i'm guessing that would be fine...any reason "not" to do that? I know magnum primers are only supposed to be used for specific powders loading 357 magnums...

mikld

Normaly today's reloaders will use magnum primers for slow burning ball powders; W296/H110. I use magnum primers in my .44 Magnum WC820 loads, don't know if it's really necessary, but it works for me...

Iowegan

Chris Brines, Unique powder in a 357 Mag is far from optimum. Yes, it will work fine for mid-range loads but if you want to get full magnum performance, I would highly recommend using H-110 or W-296 powder, both of which require mag primers. With mid-range Unique loads in a 357 case, if you back off your powder charge about .5 grains, magnum primers will work OK. If you are loading at the higher end of the charts, then I would not recommend using mag primers with Unique.

MidLife

Magnum primers are not linked to "magnum calibers".

Just because a cartidge is designated "magnum" does not indicate a requisite "magnum" primer.

For example, a "357 magnum" round does not dictate a magnum primer. The powder/and load dictates the required (or recommneded) primer requirement.

MZ5

As recommended on Shooters Forum, where this was also posted, follow your loading manual exactly. There's simply no way to tell in advance whether a magnum/non-magnum primer swap will increase pressure, decrease it, or what other changes it may cause.

Iowegan

MidLife, Well ... kinda, sorta, usually .... depends on what reloading manual you use. If you look in the Hornady 7th Ed manual, all jacketed bullet loads listed for 357 Mags use Winchester Small Pistol Magnum primers, however none of these loads use faster burning powders. If you look in the Speer manual, only loads with slow burning "magnum powders" use CCI 550 Small Pistol Magnum Primers and are noted with a * next to the powder type. Much the same for 44 Mags where Hornady uses Winchester WLPs for all loads and Speer only uses CCI 350s with magnum powder loads.

In the same manuals, if you look at other "non-magnum" cartridges such as 9mm, 40 S&W, 38 Special, etc ... you will not see magnum primers listed for any loads nor will you see magnum powders listed either. There is obviously a good reason!!!

So if I'm reading between the lines correctly on your post ... you are saying "primers are linked to the powder ... not necessarily the cartridge", which I totally agree with.

MZ5, I certainly agree with your first statement ... follow the reloading manual's recipe to a "T". Your second statement is mostly correct too, however I can't imagine a single case where a magnum primer would lower chamber pressure, assuming two loads were otherwise identical.

The point is ... when you try to second guess reloading manuals and substitute components of any type, the outcome will most assuredly be different ... possibly dangerous.

MidLife

Yes. A 357, or 44 or other "magnum" loaded cartidge or round, as defined by general ammunition definitions, does not require a "magnum" primer. The word "magnum" is different context in these phrases. Primers are designated as "magnum" apart from rounds or cartridges designated as "magnum".

In other words, a magnum primer does not a magnum round make, nor does a magnum round make a magnum primer.

MZ5

Okay, I was stuck in my rifle context. Sorry about that, folks.

...Nothin' to see here, move it along...

Iowegan

MZ5, You might want to do some more research ... there are many ball/spherical powders used in handgun loads that do not use magnum primers ... in fact most of them. Some of these are: W-231, HP-38, AA-2~AA-9, Trap 100, 452AA, W-540, and many more. About the only ball/spherical handgun powders that use mag primers are H-110, W-296, Lil'Gun and maybe a few more slow burners.

Sr40ken

Speer actually warns not to use magnum primers on thier loads using 2400 and another for(have to get the book out at home) the .357. Hornady does use magnum primers but less powder. I've started using 300MP and Alliant doesn't call for magnum primers.

Southerngunner

Perhaps Iowega can answer this question for me. For all of my handgun loads for the last few years I have been using Winchester primers, and both large and small boxes say they will work for magnum or standard loads. I understand they will work but I formerly used CCI which had a definate difference between the two when compared with the same powder charge. The mags seemed hotter almost like the case had an extra grain of powder.