40 S&W question/issues

[moorvogi]

been reloading for a couple years but new to casting bullets. and always have something to learn.

i cast some bullets, resized them and about 95% of them are fine.. however... every once in a while the slide wont shut (semi auto).

i had reloaded probably 800-900 rounds of FMJ bullets and no issues. i changed to cast bullets and i'm having issues. I'm not sure what to share because i have no idea wahts going on.. open to thoughts ideas... things to check etc.

[Patricklaw]

I’m not sure you’ve given enough information to comment. If you’re looking for “the book”, here it is:

http://www.lasc.us/Fryxell_Book_textonly2.pdf

Have fun.

[jdfoxinc]

Pull the recapping pin from your sizing die and run the problem cartridges through the die. This may undersize the bullet affecting accuracy, possibly causing some leading,(I haven't had that problem).

[moorvogi]

skimmed thru that book, seems to be a lot of info in there worth reading. thanks!

[moorvogi]

Pull the recapping pin from your sizing die and run the problem cartridges through the die. This may undersize the bullet affecting accuracy, possibly causing some leading,(I haven't had that problem).

It took me a minute to figure out what you were saying but i'm with you now. As in, perhaps i just dont have enough crimp on there after flaring the mouth open?

Assuming this fixes the issue... do i look for a new seating/crimping die? right now i'm using a 3 die setup (deprime, powder thru and bullet seating).

[3leggedturtle]

Boolit is too fat up front, seat a few thousands deeper, or have DougGuy throat your barrel. Todd

Also did u look at the rounds that didn’t chamber? We’re the boolits deformed or have rifling marks on them?

[Jniedbalski]

Your over all leingth could be to long with that type bullet. Your bullet to big to fit the troat. Maybe it’s tight . The ones that don’t chamber can you push the slide forward and then shoot? If you can reduce over all leingth and reduce the charge if below minimum leingth

[fast ronnie]

Lee makes a factory crimp die for .40 S&W that sizes the case as the case is being withdrawn from the die. If there is any wrinkling of the case or a bell that isn't quite crimped enough, it will iron it out. I use a Lee bulge buster on every single .40 S&W that I load. The Bulge Buster kit is used with the Lee factory crimp die.

[wrench man]

i had reloaded probably 800-900 rounds of FMJ bullets and no issues. i changed to cast bullets and i'm having issues.

Are you seating and crimping in the same step?, if so you're probably getting a bur of lead in front of the case mouth not letting it go into battery, I had this issue and started seating and crimping in two step and the issue disappeared.

[slughammer]

Pull your barrel and plunk test 50 rounds into the chamber to see if they go flush. It could be seating depth or a case sizing issue
Nothing wrong with a 3 die set (I prefer 4 die sets). If you are shaving a ring of lead, try a little more flare with die number 2 and a little less crimp with die number 3.

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[popper]

Do the plunk test. If case head is flush with the hood, OK. Check OAL on ones that don't. Run loaded down all the way in the seater/crimped die ( pull the stem up) on ones that aren't flush. They will chamber and shoot but may lead.

[bstone5]

I use the Lee factory crimp die to iron out the cases on the 40 S&W. Since I Started using the factory crimp die all assembled ammo passes the plunk test.
This die solves a lot of problems with the 40 S&W.

[roysha]

I use the LEE TC style bullet in 9mm, 40 S&W and 45 ACP. All 3 guns are SIGS. I had to throat all of them because of the exact same experience you are having. The throats were all, apparently, designed for a bullet that is not groove diameter beyond the case mouth, which the TC bullet is if you seat it out far enough to crimp.

So. I would suggest you throat your barrel or perhaps, change to a different bullet style.

There are a couple of fellows here that do not believe a crimp is necessary, just a straightening of the case mouth flare, and if you follow that line of reasoning then you can seat deep enough to clear the throat. However, I for one, have seen enough KABOOMS, that although I can't verify that they were caused by bullet set back, knowing the details of each one, causes me to crimp everything, to some degree.

[slughammer]

The taper crimp die only does a little to hold the boolit. Case tension from sizing and more precisely the tension remaining after the expander has been used is what holds the boolit. If your expander is too big in dia you will loose tension. Also, if you taper crimp too hard you size down the lead, the brass springs back and you loose tension.

When setting up new handgun dies I use the edge of my bench and push a loaded round against it to see if I'm getting enough case tension to prevent setback.

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[rsrocket1]

I now size all my 401-175-TC's to 0.401" but I still prefer to seat to 1.10". The throat of my M&P 40 is just slightly over 0.401" and I can get a failure to go fully into battery once in a great while if I seat to 1.135" COL with the straight part of the bullet sitting above the rim so seating to 1.10" eliminates that problem. I use a Lee FCD without the stem screwed down so that the carbide ring only touches the top of the case and straightens out the bell without going down any further. It does the same as the taper crimp die but is not dependent on the exact case height.

[Time Killer]

You also may want to check the base of your brass to make sure there is not a slight bulge on the ones not going into battery. 40 brass is known for the Glock (Smile) bulge. I check every 40 round I reload. I will bulge bust them if it is just slightly bulged but if the bulge is significant I toss the brass. No only do I worry about a major failure I have also found that the major bulges do not chamber some times even after bulge busting do to brass spring back. This is not just a Glock issue though. Any unsupported chamber can cause this. Also there are some 40 barrels with larger than normal chambers that create full brass bulging issues.

I have a 40 Glock and its the one gun I do not reload for. I also have a 40 AR style rifle that I do reload for. I have found it to chew threw full power 40s also. Greatly reducing there reload life. I reload reduced power loads for it due to this issue. The 40 is just one of those calibers that is maxed out at its current load specks. I have also found that 165 grain and under bullets seem to be more brass freindly than the 175 plus grain bullets.

[glockfan]

Boolit is too fat up front, seat a few thousands deeper, or have DougGuy throat your barrel. Todd

Also did u look at the rounds that didn’t chamber? We’re the boolits deformed or have rifling marks on them?

this. i suspect it's the boolit profile up near the meplat who is fatter than the jacketed you were loading before.in such case,shorten your coal, then set a lower charge accordingly to the lenght you removed from the coal. and you should be good to go. of course set your crimp die just enough to remove the bell,don't crimp too much,it would swag the boolit base which is no good for accuracy.

[Tackleberry41]

Few modern pistols are throated, most shoot factory jacketed, no need. Cast it does become an issue that varies by the gun. Cast you need to expand more, what comes w Lee dies will only work w jacketed. using cast they get swaged down seating them. The NOE expanders do wonders. And do not even try the factory crimp die, it will swage them down to. I use the NOE 200gr in my various 40s, loaded properly they work in anything.