Firearm & Gun Forum - FireArmsTalk.com

Firearm & Gun Forum - FireArmsTalk.com (http://www.firearmstalk.com/forums/)
-   Ammunition & Reloading (http://www.firearmstalk.com/forums/f30/)
-   -   Magnum primers for 9mm (http://www.firearmstalk.com/forums/f30/magnum-primers-9mm-107864/)

amstutz 06-16-2014 01:41 AM

Magnum primers for 9mm
 
I stopped in my local gun shop on sat to inquire about supplies. No powder but he had a box of primers. When he handed it to me I noticed they were magnum primers (cci 550's). I looked puzzled and he quickly said "these are fine, no problem, don't worry use 'em just like the 500's I promise you will have no problems at all". I bought them. And now am having second thoughts. I'd like some opinions from you experts. Should I use them the same as the 500's? Or not?

c3shooter 06-16-2014 02:22 AM

No, you don't.

Magnum primers have a pinch of powdered aluminum, burn hotter, giving higher pressures.

General rule of thumb is reduce starting load by 10%, but would check w/ manufacturer. Other folks may have advice for you.

mseric 06-16-2014 02:39 AM

You will be fine, just start your load work at the "Start" charge and work up. No need to go below Start.

Rick1967 06-16-2014 02:52 AM

I use mag primers for everything. I just use the starting load in the book.

BillM 06-16-2014 03:03 AM

I see a 10-15 fps increase in velocity with small pistol magnum. If you are
running a striker fired gun you may or may not have issues with light strikes.

When I was loading for 9mm minor, 9mm major, 40 minor and 40 major for
USPSA competition, I used Winchester SP magnum in everything--but ran
a stock striker spring in my Glocks. No problems.

samnev 06-16-2014 06:47 PM

Quote:

Originally Posted by c3shooter (Post 1590794)
No, you don't.

Magnum primers have a pinch of powdered aluminum, burn hotter, giving higher pressures.

General rule of thumb is reduce starting load by 10%, but would check w/ manufacturer. Other folks may have advice for you.

That's exactly what I did with the magnum primers. Then work your way up very slowly. IIRC I ended up using about 10% less powder that what I had been using.

JonM 06-18-2014 04:30 PM

Quote:

Originally Posted by c3shooter (Post 1590794)
No, you don't.

Magnum primers have a pinch of powdered aluminum, burn hotter, giving higher pressures.

General rule of thumb is reduce starting load by 10%, but would check w/ manufacturer. Other folks may have advice for you.

this.

the issue with magnum primers in very small charge weights is over pressure. there is so much energy coming out of a magnum primer its possible to get detonation instead of a controlled burn.

on the other hand since the charge weight in a 9mm is so small you probably wont notice it if it does.

if your getting flattened primers in a 9mm your pressure is too high.

cratering: where the primer metal is flowing into the firing pin channel

http://i1222.photobucket.com/albums/...P-WST-48_4.jpg

flattened primer. not necessarily sign of over pressurein some cartridges. but in a 9mm it is the primer has flattened and totally filled the primer cup.

http://media3.dropshots.com/photos/1...3/b_102258.jpg

none of these are ways to measure pressure. they are merely indicators you need to back off.


All times are GMT. The time now is 02:31 PM.

Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.