The Firing Line Forums

Go Back   The Firing Line Forums > The Skunkworks > Handloading, Reloading, and Bullet Casting

Thread Tools Search this Thread
Old January 28, 2013, 11:03 PM   #1
Senior Member
Join Date: January 31, 2010
Posts: 105
is it safe to use magnum primers in 38 spl ?


I can't find any small pistol primers anywhere. My normal load (for a 1962-vintage S&W model 10 in 38 special) is 3.2 grs of Bullseye. would it be safe to load CCI magnum small pistol primers with this load? Should I reduce the load to 3 or even 2.5 grains? I don't want to stress the pistol as I am quite fond of it.

would such a load be safe for a model 36 snubbie as well?
jambrdly is offline  
Old January 28, 2013, 11:05 PM   #2
Senior Member
Join Date: April 16, 2011
Location: Georgia
Posts: 1,485
Not saying that it is the right thing to do and not recommending it, but I have used them several times without a problem, but I backed off the powder charge about 10%.

Last edited by shootniron; January 29, 2013 at 12:40 PM.
shootniron is offline  
Old January 29, 2013, 12:22 AM   #3
Join Date: January 27, 2013
Posts: 21
I just shot some today in 38 spl out of my 357
Hunter_17 is offline  
Old January 29, 2013, 07:22 AM   #4
Senior Member
Join Date: June 12, 2007
Location: North Central Indiana
Posts: 407
This is where a chronograph would come in handy. Just chrono your known loads with a standard primer and then go for the same velocity with magnum primers. Eezy Peezy.
straight-shooter is offline  
Old January 29, 2013, 11:42 AM   #5
Senior Member
Join Date: May 26, 2008
Posts: 472
Drop your load 10%, then work back up.

floydster is offline  
Old January 29, 2013, 12:06 PM   #6
Senior Member
Join Date: May 3, 2009
Location: Central Texas
Posts: 3,543
I use small rifle primers for mine. Start at the starting load work back up to your present load watching for pressure signs.
No matter how many times you do it and nothing happens it only takes something going wrong one time to kill you.
m&p45acp10+1 is offline  
Old January 29, 2013, 12:09 PM   #7
Senior Member
Join Date: February 2, 2007
Location: Iowa
Posts: 2,676
Generally I just reduce loads by 1/2 a grain and call it good.
L_Killkenny is offline  
Old January 29, 2013, 12:41 PM   #8
Senior Member
Join Date: September 27, 2004
Posts: 4,811
Drop your load 10%, then work back up.
This is the best thing to do.
Allan Quatermain: “Automatic rifles. Who in God's name has automatic rifles”?

Elderly Hunter: “That's dashed unsporting. Probably Belgium.”
wogpotter is offline  
Old January 29, 2013, 02:12 PM   #9
Senior Member
Join Date: February 7, 2009
Location: Southern Oregon!
Posts: 2,307
No! Stop what you're doing and send me all those dangerous magnum primers. I'll dispose of them safely
My Anchor is holding fast!
I've learned how to stand on my own two knees...
mikld is offline  
Old January 29, 2013, 02:43 PM   #10
Join Date: March 4, 2005
Location: Ohio
Posts: 13,654

You didn't say if you were shooting 148 grain wadcutters seated flush with the case mouth or some other bullet seated further out. The difference it makes is that the former doesn't leave a lot of empty space in the case where the latter would. In the latter instance you may actually find you get better accuracy from magnum primers just because the do a better job of pressurizing all the empty space. A magnum primer behind a 158 grain round nose bullet seated to the max .38 Special COL is probably making lower pressures than standard primer behind the deeper seated 148 grain LWC is.

Broadly speaking, though, the advice to reduce charge is good. In .223 I've seen magnum primers make the equivalent pressure difference of about a 4% increase in powder charge, so I only drop rifle loads 5% when making the small rifle primer switch. The smaller volume of the handgun, though, probably makes the 10% reduction more reasonable to do. If it were a rifle cartridge I'd then say to roll six rounds that go up in 2% steps, but that's too small for most scales to weight in your case. So I like the idea of just dropping the load half a grain, then going back up in 0.1 grain increments to see if you can tell the difference.

In the end it may make no difference at all. The primer may just unseat the bullet sooner, leaving the net peak pressure largely unchanged because the powder starts building pressure in a larger volume. Can't know until you try, though, and that's why the reduction and build up is a good plan.

As also suggested, a chronograph would make this a lot easier.
Gunsite Orange Hat Family Member
CMP Certified GSM Master Instructor
NRA Certified Rifle Instructor
NRA Benefactor Member
Unclenick is offline  

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

All times are GMT -5. The time now is 10:15 PM.

Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
This site and contents, including all posts, Copyright © 1998-2016 S.W.A.T. Magazine
Copyright Complaints: Please direct DMCA Takedown Notices to the registered agent:
Contact Us
Page generated in 0.05666 seconds with 9 queries