40 S&W bullet sizing

[DougGuy]

If you are dead set on taking that 40 into the bear woods, don't hesitate to have that barrel throated so it doesn't confine you to shorter COA and or boolit diameter small enough that it will feed reliably. Load up a dummy with your 200gr and see what the maximum length your magazine will cycle with. Now pull the barrel and use it for a plunk gauge, see how much of that same dummy case sticks out from the barrel hood.

*IF* the barrel was throated to the point where the longest dummy that you can cycle through the magazine will now plunk and turn, now you can start figuring out load data. This way you have effectively exposed the maximum amount of case volume so you probably have some wiggle room with powder charges.

[justindad]

After letting the slide slam home a couple of times on the loaded round, I see a ring on the ogive of the bullet about 5 thou above the case mouth, indicating (I believe) that it is headspacing/bottoming out on the bullet.

Since the bullets mic out at .403-4035, I will try the .401 and see if that gets me there.

Thanks, all.

5 thou is pretty small, so you could be head spacing on the boolit. On the other hand, you may have the boolit hitting the barrel throat. If the lead is wide and your throat shallow, then sizing down your boolit will do nothing. Can you measure the ogive diameter at the indentation?
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Consider making a few dummy rounds without crimping after you seat the boolit (requires a very light case mouth bell, if any at all). Attempt to chamber the boolit, if it fails to chamber then seat deeper by 10 thou and repeat. The WFN makes your boolit shorter than the RCBS version used in the manual, so you have some room to shorten your OACL. Just be aware that there are aspects of bullet design that can increase pressure for as of yet unknown reasons.
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Your brass may have sized your boolit for you, so pull one and see if the size is still .403”.

[DougGuy]

With an unthroated barrel it's a safe bet that it will not ever plunk with a .403" with ANY of the sides of the boolit ahead of the case mouth. Like where the ogive of the boolit is marked .005" in front of the case mouth, I suspect that the boolit was seated out farther, and was hammered back into the case by the OP's numerous attempts trying to get it to go into battery.

Meaning that if he would have ejected the round the first time it wouldn't plunk, the "witness" mark would be a good bit farther up from the case mouth than .005"

The 40 is MUCH harder to load for successfully with heavier (and longer) boolits that need to be seated far enough in the case that it will feed and plunk. And this compounds the pressure issue. It NEEDS the throat relieved so that a longer COA can be used.

[44Blam]

With 40 S&W, I've had great success with the NOE HTC-402-188-WFN and AA #7 powder. The HP and CUP points tend to chamber a bit easier than the flat points...