Too light of a load for .40 S&W?

[Luggernut]

I shoot IPDA SSP. The power factor (speed in ft/sec * grain of bullet) needs to be over 125,000. However with a 180gr Berrys bullet I'm way over the req's power factor with just 6.2gr of Power Pistol, 1.125 COL, WSP. This combination gives me about 925 ft/sec... or a power factor of about 166,000. According to this formula I can be shooting in the low 700s and still make 125,000 power factor.

Question is: Is this way to slow for this round? Obviously I'm not even sure if the gun will function properly. Anyonr used Power Pistol with less that 6.0gr in a similar set up?

 

[Redneck with a 40]

I doubt any load at 700 fps would even cycle the action properly, you'd probably get stovepipes and mis-feed's. My powder puff loads with 180 grain Lasercast bullets with 5.1 grains of Unique, still push 850-900 fps, these functioned fine, althought they were not as accurate in my gun.

My current load is a 155 grain Ranier with 6.5 grains of Unique, these make "major" at 1050 fps and are very accurate, I like this load.

 

[jeepmor]

Just trickle the load down and find out. I loaded some cowboy action loads for my 45 out of the Speer 13 manual and loaded them in them in the middle of their suggested range. I had a couple stovepipes and the brass was landing on or near my feet. A grain more would have done the trick.

I'd say go for it in a competition environment. The less recoil you experience the faster you get back on target, the lower your times will be. Also, it's less wear and tear on your gun.

Either that, or use lighter bullets to reduce the other multiplier in your equation.

 

[Jim Watson]

I dunno about light loads with P.P.
The .40 Minor guru of my acquaintance uses Titegroup.
He also uses lighter than standard recoil springs, so if you cut a .40 down to .38 Special ballistics, you might have to tinker with the gun.

 

[LotI]

You didn't mention the gun...

These are my (limited) powder-puff loads:

4.5gr. Power Pistol behind a 180gr. Hornady HAP bullet @1.135". Claimed speed was 738. Chronograph out of my 3.6" bbl P239 says 672 fps average and it cycled just fine.

Next slowest that I have tried was 5.0gr. WSF; 180gr. Speer Gold Dot @ 1.118". Claimed 860 and my little gun spit them out at 797fps average.

YMMV.

This article says they needed 135,000 units minimum

I haven't tried them yet but I found an online article on light .40 cal loads and they went down to 3.4gr. Bullseye and 3.2gr. Titegroup. I made note of the loads but not the article.

Edit: Here's the article! Loads are on page 2.

 

[Spartacus451]

There is really no such thing as too low as long as you aren't getting squibs. .40 S&W is overkill for minor power factor which is why you can load it so light. It may cycle at that speed but you are still going to be running at the edge of reliability so it is best drop the recoil spring until it feels like the slide is cycling positively and the empties eject a decent distance. I can run my 9MM Sig (standard spring) with a 700 FPS 147 grain load and it cycles fine. You will want to have a little extra power to knock down steel.