Magnum primer question

[jpex]

I load for several big bore revolvers, 41 mag 44 mag 475L 500JRH 500WE. I use HS-6 2400 AA#9 4227 H110.
I know I don't need magnum primers for HS-6, but does it hurt anything to use mag primers in all my
other loads. I know mag primers are a must in H110 loads but some published loads call for mag primers
with 2400 and AA#9 some call for standard. Some use WLP which I feel is in between. I mean across the
board with all calibers there seems to be a difference of info even from the major powder co.'s. I shoot Ruger's
and BFR's so any safe loads are no problem. Can anyone enlighten me?

[450ak]

Our testing showed the Remington 2 1/2 was significantly better than other primers in the 475, on up. We shoot plain base bullets which is why we don't care for CCI 350s. We also don't use 110/296 very much as we are happy with WC820. Our load for thirty years has been a 310 Keith, 20.2 of wc820 in the 45 colt. The cci300 is a good primer also. The federal 155 in the same load verges on dangerous pressure swings but its great in the 44 Magnum. The WLP is OK for unique and trail boss loads but weak for high performance loadings.
Large pistol primers are a study that needs to be done by a ballistic lab which is where we did our research. Quite a difference from different brands. Your chronograph is your friend.

[zeus]

I use WLP for almost everything personally.

[COR]

...well In regards to HS-6...all I ever use is magnum primers.

I like WinLP myself but I am trying Federals recently too.

H110/w296 is always best with Mags as you mentioned.

[jpex]

Thank you gentleman for your replies. If I chronograph a 44 mag with a 300 gr hard cast bullet over 16 grains of 2400
using one round with a LP primer and another with a LPM primer, how do I determine if the LPM gave me a dangerous pressure
spike. Assuming I don't have primers falling out or trouble getting a case out.

[jimtx]

Trouble getting a case out doesn't have to always do with high pressure, dirty chambers, overly thick web brass, etc can cause it. Measure the base of the case before and after you fire the round many manuals publish info regarding high pressure signs. Obviously a primer blowing out is a sign, but there have been dangerously high pressure loads tested and cases still fell right out. 

[JSilva]

Hello,
With loading Magnums, I side with the published load data for my recipe. If I had access to pressure testing equipment, it would be another story.
I justify it this way: if the highly educated chemists and ballistic techs who put these loads together don't specify magnum primers, there's probly one of a great many possible reason.

With regards to pressure signs, I avoid their use.
I'm sure you know that pressure signs are unreliable for measurement and sometimes do not show up until maximum pressure has been passed by a good margin.
On the other side, a loose gun chamber may show pressure signs at perfectly fine pressures.

All this is said with grains of salt, I am no expert. Take it as you like for optimum flavor.

Justin

[bradshaw]

Aug 28, 2016 15:41:31 GMT -5 jpex said:

I load for several big bore revolvers, 41 mag 44 mag 475L 500JRH 500WE. I use HS-6 2400 AA#9 4227 H110.
I know I don't need magnum primers for HS-6, but does it hurt anything to use mag primers in all my
other loads. I know mag primers are a must in H110 loads but some published loads call for mag primers
with 2400 and AA#9 some call for standard. Some use WLP which I feel is in between. I mean across the
board with all calibers there seems to be a difference of info even from the major powder co.'s. I shoot Ruger's
and BFR's so any safe loads are no problem. Can anyone enlighten me?

***

jpex.... you may as well have stepped on the .44 vs .45 minefield. The subject of standard vs magnum primers ignites emotions. Yours is a hypothetical question looking for a specific answer. More silhouette matches and championships have been won with mag primers in magnum revolvers than with standard primers. To include the first World Revolver Championship, which was won with the great Sierra .44 240-grain Jacketed Hollow Cavity (JHC) seated over 21-grains Hercules 2400 in Winchester brass, sparked by the CCI 350 Large Pistol Magnum primer. Ruger S410N Super Blackhawk 10-1/2-inch----a.k.a. Silhouette Super----factory everything right down to walnut scales.

Beaucoup tournaments and championships won with .44 Mags fueled by 296/H110, IMR & H4227 with, yes, mag primers. One may back off of the mag primer under a blazing summer sun in the Southwest, or otherwise overheated environ. Yet, trouble under high heat may be avoided by backing off the powder one or two grains. Heavy-for-caliber bullets change the tune, with the holdback (inertia) of the weighty slug contributing to full ignition of the slow powder.

As a rule, there nothing to be gained by using a mag primer to ignite fast and medium burn powders. Slow powders often benefit from sharper ignition. As stated, the inertia of a heavy bullet enhances ignition. In this environment the mag primer may increase velocity & extreme spread a percentage point, with nearly identical accuracy.

I have loaded mag primers over fast powder in .45 ACP and .38 Special when the standard primer was unavailable. Just back off the fast powder by 1/2 or 2/3-grain. In times of scarcity you have use what you got to get what you want. Experience and common sense spell success. A primer alone cannot compete with an inappropriate powder/powder charge to detonate a gun.
David Bradshaw

[jpex]

Thanks again for all the responses. I too follow published data but I have several loading manuals and
now us old timers have this thing called internet. It is just that sometimes 3 different manuals give you
5 different answers and they are all qualified experts in their field. I don't use data from a shooting a
forum unless I can verify it with a manual because I don't take chances with my eyes and fingers and I
don't need to reinvent the wheel. Mr. Bradshaw, thank you. I tend to try and use what I have and your
advice reinforces what I had thought. I am new to this forum and did some more research in older posts
here and have gotten some valuable insights.

[tek4260]

In my minimal testing, I found that with H110 loaded to 100% density, the WLP primer has lower ES than the magnum primers. I also use heavy cast lead bullets and have the expanders turned down for maximum case neck tension. whether there is any practical difference in accuracy, I cannot say. But, when one primer gives single digit ES, and the other bumps on 100fps ES, I can't help but think the more consistent load is the better load.

[bradshaw]

tek4260.... please share with us the specific load, or loads, with H110, wherein Winchester Large Pistol primer produces "single digit" Extreme Spread (ES); while a mag primer winds the same load to "100 fps" ES.
David Bradshaw

[f3]

Pertaining to the original question their can be huge pressure differences between primers. Handloader published some info from Western Powder that with no other change than primer in Large pistol and Large pistol magnum primers showed a 10,000 psi differences..

[tek4260]

Aug 29, 2016 23:29:35 GMT -5 bradshaw said:

tek4260.... please share with us the specific load, or loads, with H110, wherein Winchester Large Pistol primer produces "single digit" Extreme Spread (ES); while a mag primer winds the same load to "100 fps" ES.
David Bradshaw

Give me a bit and I'll see if I can duplicate the test. I remember I was using H110 and the Lee 300gr GC. I can't remember if the charge was 21 or 23gr. I'll load a few of each charge and primer combination and shoot them across the chronograph. All the pertinents were lost when a forum shut down.