Going to load some .40 S+W. Primer choice, starting loads?

vaalpens said:

Not exactly the same case. The neck will be shorter if you use a .40 case for 357sig, and neck tension is something you need to watch when loading 357sig.

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close enough for government work

vaalpens said:

Not exactly the same case. The neck will be shorter if you use a .40 case for 357sig, and neck tension is something you need to watch when loading 357sig.

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If a guy was to trim and form a 10mm case, would that work, even with the lg primer pocket....?.....I don't know if .357 SIG is lg or sm primer....

Mark_Mark said:

you know that .40 can become a .357 Sig very easily

same case too... my next project

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.357's formed from .40 will be a good bit shorter.

I formed 1000's 20+ years ago, but if you can get the proper brass, don't reform .40's.

The Sig neck is already ridiculously short, going shorter increases the chances of bullet setback and skyrocketing pressures.

Swampman said:

.357's formed from .40 will be a good bit shorter.

I formed 1000's 20+ years ago, but if you can get the proper brass, don't reform .40's.

The Sig neck is already ridiculously short, going shorter increases the chances of bullet setback and skyrocketing pressures.

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I noticed how short the neck was! you suggested loading the longer bullets? 147gn?

I used to load long bullets and use a bulky powder that supported the bullet to give extra insurance against bullet setback.

I still suggest that you use actual .357 Sig cases if at all possible.

MFInc said:

Just got back from test firing them all. everything worked. I didnt have a target as the wind made it moot. But I've shot my pistol enough to know that they were seemingly fairly straight shooting. Will analyze the cases later, have to run errands now though

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Good deal. I’m presuming these were TG and WSF? Any qualitative statements for the different powders? I started with TG and .40 and it was an acceptable combination but ended up shooting a lot of WST in .40. Just in case you see an opportunity to obtain some - and it works in other calibers as well. I stepped in 9mm quicksand so I haven’t shot .40 in a while but recently obtained a limited gun and now have to develop loads for that. Good luck!

Soonerpesek said:

If a guy was to trim and form a 10mm case, would that work, even with the lg primer pocket....?.....I don't know if .357 SIG is lg or sm primer....

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I've never actually done it, but my assumption is that 10mm would be a better donor case than .40 since you'd have a full length case neck.

But to me it'd make a lot more sense to just offer a trade in the "Buy, Sell and Trade: Reloading Components and Gear" forum, your 10mm for .357 Sig.

Swampman said:

I've never actually done it, but my assumption is that 10mm would be a better donor case than .40 since you'd have a full length case neck.

But to me it'd make a lot more sense to just offer a trade in the "Buy, Sell and Trade: Reloading Components and Gear" forum, your 10mm for .357 Sig.

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Understandable.....I don't have anything chambered in, or load for, .357 SIG......Just curious.

MFInc said:

I went with WSF in all of them. It seemed to burn cleaner less sooty than the CFEP I was using with the 9mm loads.

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I'm not sure what you are looking for in .40 loads, but I like W244 with 180gt jacketed bullets in .40. I actually have a few Berrys 180gr FP plated bullets loaded up, but haven't tested them yet. I will post my results once I had time to test them for accuracy and also velocities.

With CFEP my most accurate load in .40 so far has been with 155gr bullets. I probably haven't tested enough 180gr bullets with CFEP, but I will probably get some testing done in the future since I now have mostly 180gr bullets.

Good luck with your .40 loads and be safe.