Wincherter Large Pistol primers VS. Regular Magnum primers

[PoFF]

I've known for a long time that Winchester is not making magnum large pistol primers because their regular large pistol primers are already hot enough to light magnum loads, which seems to be true as I've been using them for .44 Magnum with "magnum-primers-needing-powders" without problems. But the store where I was usually buying these primers ran out of stock (Le Baron, not very surprising), so I had to switch for Federal Large Pistol for my .45, and I am on the look for magnum primers for my 44.

My question is : Is there a big difference between WLP and, let's say, CCI Magnum Large Pistol primers? Any issues I should be aware of, as I never used Magnum primers before.

Help will be greatly appreciated.

 

[Rapt]

No offense but this gets asked a lot. Might be worth doing a search although I no the threads do eventually disappear.

Basically don't even switch brands, let alone types (magnum/non magnum) without backing off your loads and working back up... (Unless you're WAY below max anyways.)

Just switching brands can cause SIGNIFICANT pressure differences. One set of tests showed something like up to a 20% pressure increase was possible using the same loads/brass/bullets and only changing brands of primers.

 

[anchor3593]

I've been experimenting in the cold with a .45 acp - found that CCI magnum primers gave me 65 fps with clays, 80 with Universal and 95 with Longshot over Remington LP primers. It seems that the longer burning powders need magnum primers to light 'em up before they leave the barrel in the cold - or with shorter barrels - faster burning powders like Clays may be much better for the cold. Extreme spread and standard deviation with Clays - for me - are one third of Longshot - again - in the cold. These experiments are using 185 fp Ranier and 200 rn Ranier in a 345 Ruger in a temp range of - 25f to +10f. Built a warm box with hot water bottles to keep the chrono working.

The difference in pressure from a standard to magnum primer in the higher pressure .44 load could be quite radical I'm sure though I have no experience to confirm it. Like Rapt says - work up again.

Heres a crazy experiment result - I loaded six .45acp with LRP's - okay so they dont quite seat flush - went from a light 700 fps average to well over 900 fps - DONT TRY THIS AT HOME - the extreme spread went crazy !

 

[Handloader B.C.]

Primers

Ran out of Win. primers. Had to do the same thing - change brands. Used the chrony to help with the problem. Loading the other primers and adjusting the powder charge a little bit, I end up with the same velocity as before and the level of accuacy. Might be a fluke, but I do not think so.
Carry on!