Jamming trouble with 40s&w

Dannyboy303 · November 4, 2007, 12:25 AM

i am having trouble with the ammunition im loading for my 40s&w semi auto.

im using 155 hard cast lead projectiles with a moly coating and when i go to seat them into the brass a film of lead is peeled back onto the brass case as i push down on the press.. This is causing my pistol to jam nearly every round so im not firing it till i have fixed this problem.

Is the only thing i can do is cut the peeled bit of lead off each projectile or is there a way i can prevent this... maybe im loading them wrong?

**Unclenick** · November 4, 2007, 01:50 AM

This comes from the fact your crimp profile is starting to work on the case mouth before the bullet is all the way in. Best approach is to back the seater die out until there is no crimp, adjust the seater stem in just to get the right bullet depth, then use a separate crimping die altogether. That dies could be the Leed Factory Crimp die or the Redding Profile die.

I've read that the polygon barrels in .40 S&W lead rapidly and can cause a pressure hazard before you realize it. Make sure your barrel is not this type.

Nick

croc4 · November 4, 2007, 06:30 PM

Maybe you need to adjust the expander die a bit to create a larger bell on the case mouth?. When you set the projectile on the case right before seating it, does it go in easily? the case mouth should be larger than the projectile if not then you will shave material off the projectile.

Sigma 40 Blaster · November 4, 2007, 08:29 PM

You need a little more flare on the case mouth before you seat the bullet. I will sometimes get a little excess lube above the case rim but don't get lead shavings. Also make sure that your crimp is enough to completely knock the flare out of the case mouth.

By jam do you mean fail to feed??? You could also be having a sizing problem at the base of the brass. If you haven't isolated the problem I'd take the barrel of your gun and feed the bullet backwards to make sure it's sized right. Get a set of calipers to be sure your crimp is knocking the flare out of the case mouth. That eliminates everything but the need to flare your case mouth a little more.

November 4, 2007, 12:25 AM	#1
Dannyboy303 Senior Member Join Date: February 27, 2007 Location: QLD, Australia Posts: 116	Jamming trouble with 40s&w i am having trouble with the ammunition im loading for my 40s&w semi auto. im using 155 hard cast lead projectiles with a moly coating and when i go to seat them into the brass a film of lead is peeled back onto the brass case as i push down on the press.. This is causing my pistol to jam nearly every round so im not firing it till i have fixed this problem. Is the only thing i can do is cut the peeled bit of lead off each projectile or is there a way i can prevent this... maybe im loading them wrong?

November 4, 2007, 01:50 AM	#2
Unclenick Staff Join Date: March 4, 2005 Location: Ohio Posts: 21,061	This comes from the fact your crimp profile is starting to work on the case mouth before the bullet is all the way in. Best approach is to back the seater die out until there is no crimp, adjust the seater stem in just to get the right bullet depth, then use a separate crimping die altogether. That dies could be the Leed Factory Crimp die or the Redding Profile die. I've read that the polygon barrels in .40 S&W lead rapidly and can cause a pressure hazard before you realize it. Make sure your barrel is not this type. Nick __________________ Gunsite Orange Hat Family Member CMP Certified GSM Master Instructor NRA Certified Rifle Instructor NRA Benefactor Member and Golden Eagle

November 4, 2007, 06:30 PM	#3
croc4 Senior Member Join Date: March 9, 2006 Location: Idaho Posts: 191	Maybe you need to adjust the expander die a bit to create a larger bell on the case mouth?. When you set the projectile on the case right before seating it, does it go in easily? the case mouth should be larger than the projectile if not then you will shave material off the projectile.

November 4, 2007, 08:29 PM	#4
Sigma 40 Blaster Senior Member Join Date: July 1, 2007 Location: East Texas Posts: 997	You need a little more flare on the case mouth before you seat the bullet. I will sometimes get a little excess lube above the case rim but don't get lead shavings. Also make sure that your crimp is enough to completely knock the flare out of the case mouth. By jam do you mean fail to feed??? You could also be having a sizing problem at the base of the brass. If you haven't isolated the problem I'd take the barrel of your gun and feed the bullet backwards to make sure it's sized right. Get a set of calipers to be sure your crimp is knocking the flare out of the case mouth. That eliminates everything but the need to flare your case mouth a little more.