Hi folks, I'm yet another newb to the reloading forum here but I've been lurking quite a bit over the last few months as I've been getting my bench set up. First I'd just like to say hi and thanks for the wealth of information that can be found here in this forum.

So last week I finally got everything together and started prepping and loading .40 cal. pistol using my WWB brass. After decapping, the OAL of the brass is consistently from .840-.843. Both the Hornaday and the Lyman manuals say max length of .850. Should I be trimming these to a uniform length prior to loading and seating the bullet?

Here's why I ask that. When I seat the bullet in my Lee carbide die I'm getting inconsistent COL ranging from as low as 1.120 up to 1.140. Max OAL says 1.135. I had to keep resetting the seating depth on the die. Am I doing something wrong here or could that have something to do with not trimming the brass?  

I hope this isn't a stupid question, and thanks in advance for any help or advise.

Remember, the .40 head spaces off of the case mouth, just like the 10mm and other non-rimmed cases.  You should definitely be trimming to a uniform length after resizing.

Should I be trimming these to a uniform length prior to loading and seating the bullet?  
Those cases are fine ...run em.    For all practical purposes those cases are within spec.  You will probably never run across a long .40 case.

Straight wall cases dont have the stretching issues thart bottlenecks do.  I have NEVER trimmed a 9MM, .40 or .45
Get yourself a case Gauge..Dillon (stainless) and use it to check your resizing adjustment and case length.  They are like $20 but are priceless especially for .40
If you ever come across a long case the case gauge will catch it.

I also HIGHLY recomend a Lee FCD to remove the bell of the case mouth and resize the loaded case.  Sizing on one die and crimping on another yeild the best results IMO.

Your COAL  1.120-1.140 is most likely due to bullet tolerances or meplat or inconsistant ram stroke.  The first two the most suspect.

What press and bullets are you using?

Thanks for the info fellas. I will look into picking up a case gauge and a FCD (factory crimp die?) I've tried to keep the stroke as consistent as I can, but that doesn't mean it's not human error of some sort I guess. How would I check bullet tolerence and how much of a role does meplat play in a flat nosed bullet?

My press is a Lee auto indexing press and I'm using Winchester 165 gr. FMJ bullets.

Also, is there a index somewhere of all the different headstamps?

Thanks again guys.

Quoted: Thanks for the info fellas. I will look into picking up a case gauge and a FCD (factory crimp die?) YES I've tried to keep the stroke as consistent as I can, but that doesn't mean it's not human error of some sort I guess. How would I check bullet tolerence and how much of a role does meplat play in a flat nosed bullet? My press is a Lee auto indexing press and I'm using Winchester 165 gr. FMJ bullets. Also, is there a index somewhere of all the different headstamps? Headstamp link Thanks again guys.