Too Slow?

[gopurdue02]

I have some Berry's 180g .40 S&W I've loaded up with Accurate No2 @ 4.0 which resulted in an average of 750 FPS which is about 70 less then manual. However, I'm trying to hit power factor for IDPA with the lightest load possible and this fit's the billet as it was very soft and the three different test guns I used it ran fine (Although that was with only 50 rounds: I want to do another test with a much higher number before going into production mode). My question is this: Should I be worried I was below the books published number of 820~?

Thanks

 

[Leo]

If the load makes the speed you need and reliably functions your pistol, all is good. There is often some variance between published data due to firearm type, barrel differences, etc. I would not worry too much with any load that is not showing excess pressure.

My particular .40 S&W pistol is a little more accurate with loads faster than yours. You might bump up the charge on a few and do an accuracy test. Other than that, if you are happy, don't change.

 

[mssmith44]

There is one test you should do for an IDPA load.
There are weak hand stages where a lot of pistols seem to jam. Revolvers not so much.
Limp wristing is the cause.
Load one round in the magazine, hold the pistol as weakly as possible so as not to let it get away.
Fire the one round, if the slide locks back, you are good to go, if not bump the charge up until it does.
My IDPA loads for 40 are a little over the minimum power factor, but whatever works right in your pistol.

 

[noylj]

Did you use the exact same components and lot numbers as the manuals?
Does your barrel/chamber have the exact same dimensions as used in the manuals and the same length?
Is your bullet and COL exactly the same as used in the manuals?
Is your chronograph exactly as far away from the muzzle as the manuals?