Standard VS magnum Primers in the 45ACP

[dale2242]

I have an excess of CCI 350 primers.
I am loading a lot of 45ACP these days and was wondering if they would be suitable for cast loads.
My load is a Lyman 452460 cast of #2 alloy and 5 gr 700X in Winchester cases.
I loaded 10 rounds of each to try in 2 different 45s, one an issue 1911 and the other a Sig P220.
The loads were shot over my Shooting Chrony.
The loads were fired for group at the same time.

1911: CCI 300
Average 839 FPS
ES 43
SD 12

1911: CCI 350
Average 859
ES 55
SD 18

SIG: CCI 300
Average 794 FPS
ES 35
SD 14

SIG: CCI 350
Average 824
ES 55
SD 20

Velocities, ES, SD were slightly higher with the magnum primers.
Primers looked the same. Not a scientific way of measuring pressure, but the best I have.
Accuracy was pretty much the same with no obvious difference.
I see no particular advantage or disadvantage in using the magnum primers.
I am still undecided about using the 350s in the 45ACP....dale

[243winxb]

The WLP is what i use. They only make one large pistol primer. Good for 45 acp & 44mag. Bullseye, 700X, Unique, 296/H110, 4227 & ball powders.

Just work up loads for the CCI350.

[samari46]

Only usage of magnum primers is in my '06 with IMR 4350. Never did see the need for them in the 45acp. Frank

[tazman]

I have used magnum pistol primers in standard loads when I couldn't find any standard primers several years ago. I used them in plinking/practice type loads where I was using less than maximum pressure loads.
I am not a good enough shot to be able to tell any difference in group size in all but one instance.
That instance was in a 9mm pistol where the magnum primer actually improved my group size significantly. In this case, I believe the powder got better ignition using the hotter primer.

[mebudman63]

Well here lately I have been running CCI 350`s cause i can`t find any 300`s locally. I haven`t really noticed any change pressure wise. I haven`t seen what difference on a chrony yet.

[6bg6ga]

I doubt your going to see any difference in performance/accuracy using magnum over standard primers. Cost wise I think they are close and I just buy what I can find anymore.

[Ateam]

I have used mag primers in both pistol and rifle applications. I have moved to standard primers in all applications and find mags to have a much larger ES (4831sc, 300 win mag), and initiate early over-pressure sign (blue dot, .357mag). No doubt there are applications for mag primers but I tend to think of them as a specialty loading component. That said there is no reason that they cant be used in a load that is not near peak pressure and you don't care about a greater ES.

[Three44s]

In my opinion, a Mag primer in a small case with a fast powder is not an ideal situation.

I use Mag primers with HS6 with my 44 Mag revolvers and I recall some use of that powder in the 45 ACP but I would research that more in depth before I went that route.

As I see it, the downside would be potentially jumping the crimp and/or pressure spikes. Jumping the crimp happens when the power of the primer alone moves the bullet towards the rifling before the powder can ignite. The pressure spikes could emanate from either the bullet stopping because it becomes arrested against the lands and then the powder igniting and pushing against the somewhat stalled bullet.

The other reason for pressure spikes would be from a powder that ignites easily without magnum primers but ignited instead with a magnum and thus increasing it’s burn rate.

Three44s