magnum primers for 40 S&W

[jeffg]

I have Federal Small Magnum Pistol primers, I bought these not paying enough attention, I was looking for just small pistol primers, I was wondering if I could still shoot these in a 40 S&W.

[VegasOPM]

I have without issue. Of course it was a Glock with a stock striker, so YMMV.

[G-ManBart]

They should work just fine, but don't use them on really, really light loads. The harder primer cup may not seal properly with super light loads and that can allow gas blowby around the primer, which can/will cause wear on the gun's breachface...which is bad. R,

[sargenv]

I've used Small pistol magnum Federals in place of regular Federal small pistol and had zero issues with them in my revolver. This is the same revolver that is not reliable with CCI, Winchester, or any other small pistol primer out there. You should not notice much difference.. you might have a slight difference in velocity though.

[TonyT]

Several years ago I made the same mistake and purchased Federal SP Magnum primers istead of the normal SP primers. I used them with moderate (not full power) loads in my 40 S&W revolver. As I remember there was a ca 10-20 fps increase in velocity but that was statistically insignificant - I have experienced that type of velocity difference in day to day tests.

[Rocket35]

I asked the very same question some time ago and found the similar answers as here. I have 5K of them and will be trying them out soon.