40 S&W Brass

[m50miller]

Hello,
I have been doing a little shooting with the .40 S&W. I just purchased a Sig P-226 x-five comp. that really shoots. I have been shooting Winchester USA 165 gr. FMJ ammo. I was thinking of reloading some rounds to see what kind of accuracy I could ring out of this gun/caliber combination.

I have three reloading manuals, Hornady, Speer and Lyman. All of them show the case length of .850, with a trim to length of .845, Speer says .840. I measured 20 once fired cases and they checked .835, with a couple at .837.

I have several questions that I hope someone out there can answer for me.

Why are factory once fired cases shorter than the minimum length?

What is the minimum headspace spec. for a .40 S&W cartridge?

How much shorter can a casing be than the minimum headspace spec.?

Are there other manufactures that do a better job of maintaining case length?

I don't see how optimum accuracy can be achieved without making the case lengths uniform.

How is having the case lengths uniform going to help if all the cases are too short and an excessive headspace condition exists?

I've handloaded for .45 ACP using Winchester USA once fired brass with most cases needing a small amount removed to hit the trim to spec., with only a few going .001 - .002 under minimum.

Any help that you can give me would be greatly appreciated.

Thanks,
Mike

 

[LotI]

I have three reloading manuals, Hornady, Speer and Lyman. All of them show the case length of .850, with a trim to length of .845, Speer says .840. I measured 20 once fired cases and they checked .835, with a couple at .837.

Have you re-sized the brass yet? They will lenthen upon resizing. After firing a few times the brass will be shorter. I have never trimmed straight-walled pistol cases(9mm, .40, .45)

Why are factory once fired cases shorter than the minimum length?

See above.

I don't see how optimum accuracy can be achieved without making the case lengths uniform.

Sort by length and headstamp and reload as usual.

I've handloaded for .45 ACP using Winchester USA once fired brass with most cases needing a small amount removed to hit the trim to spec., with only a few going .001 - .002 under minimum.

I have never trimmed .45 Auto. If it's too long, toss it.

Welcome to THR!
psst...You may want to wander to the reloading forum to find the holy grail of info.

 

[m50miller]

Thanks LotI,
Mike

 

[Kimber1911_06238]

I know that cases at the maximum length according to Speer #13 manual
(.850) work flawlessly in my HK USP .40

And as stated above they do tend to shorten a bit after a firing or two

 

[Walkalong]

I have never trimmed a 9MM, .40 S&W, or .45 ACP case, never.

 

[Babalouie]

I've reloaded over 20k rounds of 40 S&W in the last three years. (My son and I shoot uspsa and our club shoots weekly) I've case gauged ever one of those rounds. Because I case guage I have never measured or trimmed the brass. About 1% won't case gauge correctly and gets tossed. In 3 1/2 years we have never had a jam or malfunction. One time we had a case blow out at the rim and blow the ammo out of the bottom of the mag...scary. Our visual inspections have been a bit more through since then. OAL (Over all length) can be longer, and we do load ours longer than factory, but not shorter!