Small rifle primers for 40S&W?

[Babalouie]

OK, I've read that a lot of IPSC shooters use small rilfe primers for their 40 S&W rounds. I have two questions: 1) Why? 2) How do you have to modify the powder charge? I currently load titegroup under a 180 grain fmj. Thanks!

 

[Zak Smith]

If you have a pistol set up to take high pressure rounds, a rifle primer can prevent primer extrusion into the firing pin hole. That is why they are used in the hot 38Super/9x23 (and some 40SW) loads in IPSC.

In many 40SW loads, other benefits include: increased average velocity by 20-40fps; decreased velocity standard deviation; and only needing to keep one type of small primer on hand if you load 223 or other cartridges with small primers.

-z

 

[BluesBear]

Be advised that the harder cups of the rifle primers may cause problems if you have a reduced power mainspring.

Make sure before you bet your life on them.

 

[Clark]

I have shot double loads in a 40sw with small pistol primers without the primer piercing [TIG welded feed ramp].

What are they using small rifle primers for?

 

[Zak Smith]

Read my response.

 

[gobabygo]

Zak nailed it. A lot of IPSC/USPSA shooters shoot both open (38 super/9mm) and limited (40S&W). Small rifle primers are used to prevent primer flow, especially on the 9mm major loads. For me I use them on 40S&W so I don't have to stock another primer.

*I* actually didn't see any statistically significant increase in velocity switching from small pistol to small rifle primers (less than the SD) and my SD only went down slightly. As usual though, if you switch primers it's prudent to reduce your load and work your way up.

 

[Jeeper]

It was a lot more common for IPSC shooter to use small rifle primers in 40 when the power factor was higher. now you dont risk primer flow. There are also problems with them at the lower power factro. Since they are harder it takes more juice to seal them in the primer pocket. If you have some brass that is old with slightly enlarged primer pockets then they might not seal which causes a round to almost feel like a squib. The gas escapes around the primer and you dont get a full power load. I stopped using them in 40 when the power factor changed a few years back.

 

[BluesBear]

In the 1970s I loaded .38 Super ammo for a Colt Commander to the point that the case was failing over the feed ramp and I never had any problems with primer flow.

I made some cases from military 5.56 cases and went even higher powder charge still had no problems with flow. Using standard CCI 500 or 550 small pistol primers I got the H&G #235? 158gr SWC-GC to almost 1400fps.

 

[Clark]

How big is the firing pin hole and how high it the pressure to get a small pistol primer to flow?

 

[Rockstar]

Hey, Clark, you don't really think those guys have pressure-testing equipment, any more than you do, do you?

 

[baker1425]

5.56 super brass?

I made some cases from military 5.56.

how? the dimensions don't look right to me, but If I can turn my excess of 5.56 brass into usuable super brass, I'm all over it.

thanks

 

[Tory]

Actually,

5.56 / .223 cases make 9x23; not .38 Super. The latter is semi-rimmed.

That said, my 9x23 SVI digests .38 Super all day, with the correct extractor and breechface.

 

[baker1425]

I'll start another thread

don't want to hijack this one more

 

[BluesBear]

baker1425 I answered you question in the other thread.