Author Topic: magnum primers (Read 442 times)

tvc15 · « **on:** December 12, 2005, 10:37:30 AM »

I have a really simple question. I am going to load 100 grain sierra bullets in my .243. the sierria book gives you all the formulas for IMR 4350 powder and makes no mention of magnum primers. Now I look at my speer book and it recommends a magnum primer for it's 100 grain bullet with the same powder. What gives? Thanks in advance, TVC15

PaulS · « **Reply #1 on:** December 12, 2005, 10:42:09 AM »

tvc15,

Chalk it up to differences in chambers, load techniques and preferences. IMR 4350 is not a double base powder and unless it is a compressed charge I can think of no reason to use a magnum primer.

warf73 · « **Reply #2 on:** December 12, 2005, 09:00:14 PM »

I don't use Mag primers for the 243, but I do use mage primers using IMR4350 in my reloading uses.

I use IMR4350 in my 300WBY & 460WBY but we are talking about case volume that is doubled that of the 243.

Doesn't/didnt IMR4350 and there slower powders have a coating on them that needed the Mag primmer to burn threw it so to speak? Thought I read that some were or heard it.

Warf

june6th1944 · « **Reply #3 on:** December 13, 2005, 03:00:57 AM »

I use magnum primers with IMR 4064 in a .30-06 Springfield, but I wouldn't see their use in a .243 Winchester. I would go with what the reloading manual recommends, you might get the accuracy you need with that little extra amount of heat and pressure.

Good luck.

beemanbeme · « **Reply #4 on:** December 13, 2005, 04:19:33 AM »

I use magnum primers only for belted cases. I have read the reccomendations about using magnum primers for large (30-06 sized) loads of ball powder in cold weather but have never had a problem with standard primers so.................. :grin:

Also, I have done enough modest tests to convince me that magnum primers does nothing for me in the accuracy department.

Danny Boy · « **Reply #5 on:** December 13, 2005, 06:09:23 AM »

Go according to the loading manual. Start with a lower charge and work yourself up. A magnum primer may give you a little extra. But alway start with a low charge.

Danny Boy

Tn Jim · « **Reply #6 on:** December 13, 2005, 06:47:55 AM »

I've read that with IMR-4350 a magnum primer is recommended in larger cases when the temps are in the single digits or lower. That being said, I've used 4350 in my 30-06 reloads while hunting for over 15 years with zero problems.