Magnum primers in 40sw

Tuvlo · February 19, 2009, 04:32 PM

I bought some primers the other day and when i got home i noticed that they were small pistol magnum primers, when i went back they would not exchange them because of store policy.
My question is would it be safe to use magnum primers in 40sw with a 180gr bullet and power pistol powder?
I know i should work back up from the starting load but with a heavy bullet could it cause spikes even at starting loads?

ShootingNut · February 19, 2009, 05:32 PM

Tuvlo
Personally I would not use a magnum primer in the .40, or any other for that matter if not called for.
But, my advice would be to email the powder manufacturer, and go with their advice to be safe.

Regards,
SN

Inspector3711 · February 19, 2009, 10:08 PM

I agree with the advice above. .40 S&W has a very narrow pressure window. I wouldn't use magnum primers.

WESHOOT2 · February 22, 2009, 09:52 AM

But I have my reasons.

Can you provide more details, such as specific primer / bullet / powder and charge weight / launch platform(s)?

madmo44mag · February 22, 2009, 10:17 AM

I have had to go the mag primer route a few times due to no STD primers available.
Each gun is different but I started at the boittom load and worked up.
Now that said, I did find a very happy medium that was very accurate and safe.

Jim243 · February 22, 2009, 11:42 AM

Do not over load the 40 S&W. Primers are cheaper than Hospital Bills or new guns.

Tuvlo · February 23, 2009, 02:07 PM

Weshoot2, i would be be using rem 5 1/2 primers, 180gr fmj, using power pistol starting at 6.1 gr and would be loading up to a mild target load, nothing hot.

Tuzo · February 23, 2009, 03:00 PM

There is always a fine and delicate balance of primer, powder, and bullet that can be personally determined by trial and error or by consulting various references.

The safest bet for most reloaders is to adhere to reloading manuals. The powder and bullet companies have taken the hazardous risk in determining what is acceptable. But if you must use magnum primers for non-magnum applications, then carefully experiment but please be aware of the dangers dealing with things that go boom. Then again, some of our modern cartridges were developed by risk takers.

WESHOOT2 · February 23, 2009, 03:39 PM

Recommend:

-OAL 1.130"+/-.005"
-size all cases
-start load 5.6g Power Pistol (make ten test ten)
-ensure sufficient case neck tension

An excellent addition is crimping separately using the LEE Carbide Factory Crimp Die, but understand crimp does not secure the bullet; case neck tension, as determined by your sizing and flare die, secures the bullet. Too much crimp can bulge the case slightly, relieving neck tension.

Hope this helps.

kraigwy · February 23, 2009, 03:42 PM

I just called CCI, asking about this question. Their Tec Support told me that CCI mag primers are 10% hotter then their regular primers.

Sierra says reduce the charge by 5% if you switch from standard primers to mag primers.

THEREFORE: If you are (like me) stuck to using Mag primers because of the shortage of reg primers, you have to start all over in develolping your loads.

WESHOOT2 · February 23, 2009, 03:50 PM

When I change ANY lot, or component, or tooling, I start low and work up.

MASTERSPYDOG · February 24, 2009, 12:45 AM

I too have had to start using mag primers because ALL the std primers are GONE and all the shops on/offline don't know when/ if they will get any within the next 4-6 months. From the info i've recieved is that the load for 40s&w starts at 4.8grns - 5.3grns for W231 using std primers; to use the mag primers I was told you should reduce the loads by one (1)grn. I have loaded 5 rounds to test with 4.3 grns, 4.1grns, and 3.9grns.

anyone else heard using this rule of reducing by 1 grn?

thanks and good luck

February 19, 2009, 04:32 PM	#1
Tuvlo Junior Member Join Date: February 19, 2009 Posts: 2	Magnum primers in 40sw I bought some primers the other day and when i got home i noticed that they were small pistol magnum primers, when i went back they would not exchange them because of store policy. My question is would it be safe to use magnum primers in 40sw with a 180gr bullet and power pistol powder? I know i should work back up from the starting load but with a heavy bullet could it cause spikes even at starting loads?

February 22, 2009, 09:52 AM	#4
WESHOOT2 Senior Member Join Date: February 20, 1999 Location: home on the range; Vermont (Caspian country) Posts: 14,324	I have, and do But I have my reasons. Can you provide more details, such as specific primer / bullet / powder and charge weight / launch platform(s)?

February 23, 2009, 02:07 PM	#7
Tuvlo Junior Member Join Date: February 19, 2009 Posts: 2	Weshoot2, i would be be using rem 5 1/2 primers, 180gr fmj, using power pistol starting at 6.1 gr and would be loading up to a mild target load, nothing hot. Last edited by Tuvlo; February 23, 2009 at 03:37 PM.

February 23, 2009, 03:39 PM	#9
WESHOOT2 Senior Member Join Date: February 20, 1999 Location: home on the range; Vermont (Caspian country) Posts: 14,324	Thank you Recommend: -OAL 1.130"+/-.005" -size all cases -start load 5.6g Power Pistol (make ten test ten) -ensure sufficient case neck tension An excellent addition is crimping separately using the LEE Carbide Factory Crimp Die, but understand crimp does not secure the bullet; case neck tension, as determined by your sizing and flare die, secures the bullet. Too much crimp can bulge the case slightly, relieving neck tension. Hope this helps.

February 23, 2009, 03:42 PM	#10
kraigwy Senior Member Join Date: June 16, 2008 Location: Wyoming Posts: 11,060	I just called CCI, asking about this question. Their Tec Support told me that CCI mag primers are 10% hotter then their regular primers. Sierra says reduce the charge by 5% if you switch from standard primers to mag primers. THEREFORE: If you are (like me) stuck to using Mag primers because of the shortage of reg primers, you have to start all over in develolping your loads. Last edited by kraigwy; February 23, 2009 at 05:45 PM.

February 19, 2009, 05:32 PM	#2
ShootingNut Senior Member Join Date: December 27, 2006 Location: Wisconsin Posts: 1,475	Tuvlo Personally I would not use a magnum primer in the .40, or any other for that matter if not called for. But, my advice would be to email the powder manufacturer, and go with their advice to be safe. Regards, SN

February 19, 2009, 10:08 PM	#3
Inspector3711 Senior Member Join Date: February 9, 2008 Location: Puget Sound Washington Posts: 1,553	I agree with the advice above. .40 S&W has a very narrow pressure window. I wouldn't use magnum primers.

February 22, 2009, 10:17 AM	#5
madmo44mag Senior Member Join Date: December 29, 2008 Location: Ft.Worth, Texas Posts: 1,522	I have had to go the mag primer route a few times due to no STD primers available. Each gun is different but I started at the boittom load and worked up. Now that said, I did find a very happy medium that was very accurate and safe.

February 22, 2009, 11:42 AM	#6
Jim243 Senior Member Join Date: January 6, 2009 Location: Just off Route 66 Posts: 5,067	Do not over load the 40 S&W. Primers are cheaper than Hospital Bills or new guns.

February 23, 2009, 03:00 PM	#8
Tuzo Senior Member Join Date: June 14, 2007 Location: Louisiana Posts: 797	There is always a fine and delicate balance of primer, powder, and bullet that can be personally determined by trial and error or by consulting various references. The safest bet for most reloaders is to adhere to reloading manuals. The powder and bullet companies have taken the hazardous risk in determining what is acceptable. But if you must use magnum primers for non-magnum applications, then carefully experiment but please be aware of the dangers dealing with things that go boom. Then again, some of our modern cartridges were developed by risk takers.

February 23, 2009, 03:50 PM	#11
WESHOOT2 Senior Member Join Date: February 20, 1999 Location: home on the range; Vermont (Caspian country) Posts: 14,324	finger count When I change ANY lot, or component, or tooling, I start low and work up.

February 24, 2009, 12:45 AM	#12
MASTERSPYDOG Junior Member Join Date: September 30, 2008 Posts: 12	mag primer use I too have had to start using mag primers because ALL the std primers are GONE and all the shops on/offline don't know when/ if they will get any within the next 4-6 months. From the info i've recieved is that the load for 40s&w starts at 4.8grns - 5.3grns for W231 using std primers; to use the mag primers I was told you should reduce the loads by one (1)grn. I have loaded 5 rounds to test with 4.3 grns, 4.1grns, and 3.9grns. anyone else heard using this rule of reducing by 1 grn? thanks and good luck