primer question

[sam77757]

can i use large rifle primers in loading my 300 win mag or do i have to have the magnum primers?

 

[AZBru88]

Sam I use Mag primers, always worried about full ignition of the powder with large rifle. I'm sure some one with more experience will chime in. My only rifle calibers are 300 Win Mag and 300 Weatherby Mag and lots of 223! Mainly a pistol shooter! Best of luck....Bru

 

[contender]

It depends upon the powder. If you are using a slow burning powder,, I'd use the mag primers. If a faster burning powder is used,, then you might be able to get away with it. As always, start with reduced loads & work up testing carefully.

 

[WYO1]

Go with whichever the loading data you are using suggests. Because the caliber says magnum, doesn't mean the best primer may be a magnum. But there are those who suscribe to other beliefs, such as, any loading using over 45 grs. of powder should use a mag., or those loads being used in cold temps should use magnum primers to assure ignition.

 

[WYO1]

Go with whichever the loading data you are using suggests. Because the caliber says magnum, doesn't mean the best primer may be a magnum. But there are those who suscribe to other beliefs, such as, any loading using over 45 grs. of powder should use a mag., or those loads being used in cold temps should use magnum primers to assure ignition.

 

[sam77757]

well im using 75g of IMR-4350 i loaded 100 with mag primers and that was the last of my magnum primer stock and with no store here selling mag primers only large and small rifle primers which i have plenty of allready i was just wondering as i have never loaded them in my 300win mag and i didnt want to just go out and try one or two to see if they worked before i asked the Experts...

 

[contender]

Without looking up your load,, in general,,most likely,, it'll be ok. The mag primers generally burn a bit hotter,, and sometimes a fraction longer,, so ignition of the powder is more uniform. You may or may not notice any differences,, but then again,, it could make a big difference.
Try contacting both the primer companies & the powder companies with your question to see what they say. They have the equipment to test such things as it relates to pressures.

 

[sam77757]

Contender that sounds like alot of hassle lol i will just wait and pick up some magnum primers offline and stick with them i have other uses for the lr primers anyways.. they are just easier to get here in town thanks guys for all your info

 

[AKGrouch]

Looked in my old 1973 Hornady handbook at loads for the .300 Win Mag. out of curiosity cuz I used 4350 for years. With no, I repeat, NO exception, the book recommends a CCI 250 (magnum) primer for the .300 Win Mag regardless of the powder used. I would listen to Contender and what he said, especially with a slow burning powder like 4350. I used 4350 for many years in a .375 H&H which needs a slow burning powder. A .375 H&H loves 4350. But, because it is such a slow burning powder a mag primer is simply a must for the big magnum using 4350 to simply insure adequate ignition.

 

[sam77757]

well my Nosler handbook shows magnum primers with every load.. the pamplet that came with my Lee Dies recommends Large Rifle primers unles using Winchester 296 powder which requires mag primers. which i dont think it made anymore.. im going to stay with mag primers after what i have heard and read myself but it is weird that different answers to the question of something so serious from different companys!

 

[mattsbox99]

Anything over 60 grains of powder, ball powders, or in sub zero temps really need Magnum primers.

There are exceptions, of course, small pistol cases and small rifle cases using ball powders should use standard primers.

Variance across loading data is inevitable, when in doubt, I defer to the company making the bullets I am using. Speer and Nosler are my two most trusted reloading manuals.