45 ACP Bullet Set-Forward

Caboclo · June 7, 2010, 10:58 PM

I've read a lot about set-back, but I'm having the opposite problem. I've loaded 1000 or so rounds with 230 RN, both lead and hard moly. Worked up a couple different loads with HP38 and Bullseye; used a combo seat/crimp die and then switched to separate dies; all was good throughout all those variations. All of those were about 1.20 COL. Then I decided to switch to 1.27 COL, at the same powder charge (4.9 Bullseye) and I started having jams. The slide would not close all the way, and would stick when I tried to cycle it manually. After I got the slide open, there would be a mark on the bullet where it had jammed against the barrel, and the bullet would be pulled out the case by about 1\32", as evidenced by a slight circumferential mark on the case where it had been crimped. So what's going on? Is the recoil of the first shot popping the top bullet in the mag out of it's case, like a magnum revolver? Or is the round just too long to feed, and it's the effort of pulling the stuck bullet out of the barrel that's pulling it out of the case? I try to use a minimal crimp, but maybe I'm overdoing it even so. I tried running some of the finished rounds through a harder crimp, didn't help.

mongoose33 · June 8, 2010, 06:54 AM

My guess: You're crimping too much, which is buckling the case a bit and reducing neck tension.

The clue that leads me to this conclusion is the crimp ring you're seeing in the bullet after it sets forward.

The .45 ACP needs only enough taper crimp to straighten out the expanded casemouth (what you're expanding to allow the bullet to enter the case and be seated).

"Crimping" in a straightwall cartridge like this is an unfortunate use of the word, as it implies something necessary to maintain tension on the bullet. Normal neck tension is enough to hold the bullet.

Your taper crimp should be just enough to straighten out the casemouth and square it up--nothing more. The .45 ACP headspaces on the casemouth; anything that starts turning that casemouth into the bullet risks doing it so much that it jams in the throat and causes you problems.

Sevens · June 8, 2010, 08:57 AM

Yes, the longer COAL rounds are too long for your particular barrel/chamber.

Depending on the shape of the bullet (even FMJ round nose aren't all the same shape) some can be loaded further out than others. When the bullet of the chambered round contacts rifling the in the barrel so much that you can't close the slide and you see marks on the bullet when you eject it, that's your obvious sign that you need to reduce the COAL of the cartridge.

As was said, the taper crimp merely re-sets the brass so that it can headspace properly, it's proper case mouth tension (set by the sizing die) that gives you bullet pull, not a crimp.

It's important to not reduce the COAL by too much (as you reduce the internal space, the pressure rises) but you must also make ammunition that fits your pistol and in your case, those particular bullets will not run at 1.270" COAL. They run at 1.200" COAL (which is a common COAL for 230gr FMJ in .45) so try again at 1.200" COAL and if those work, stick with that COAL for those bullets.

You are quite correct in that a harder crimp is NOT going to help you here in any way.

Caboclo · June 8, 2010, 06:14 PM

Thanks guys.

demigod · June 9, 2010, 09:28 AM

Take a loaded round and drop it in the barrel. (with the barrel removed from the slide.)

If the case doesn't sit flush with the barrel hood, the bullet is hitting the rifling. Sounds to me like you have the bullets seated way too long and they're lodging into the rifling and sticking when you go to eject them.

m15171 · June 9, 2010, 09:50 AM

i had the same problem with moly coated bullets from Precision. it has to do with the shape of the nose. once i set the oal to 1.20 they fed flawlesly

demigod · June 10, 2010, 12:31 PM

Indeed. The seating die usually indexes off of the bullet's ogive.

Whenever you switch bullet makers, you should chamber check your first few rounds to avoid a whole run of problematic ammo.

June 7, 2010, 10:58 PM	#1
Caboclo Senior Member Join Date: November 2, 2009 Posts: 212	45 ACP Bullet Set-Forward I've read a lot about set-back, but I'm having the opposite problem. I've loaded 1000 or so rounds with 230 RN, both lead and hard moly. Worked up a couple different loads with HP38 and Bullseye; used a combo seat/crimp die and then switched to separate dies; all was good throughout all those variations. All of those were about 1.20 COL. Then I decided to switch to 1.27 COL, at the same powder charge (4.9 Bullseye) and I started having jams. The slide would not close all the way, and would stick when I tried to cycle it manually. After I got the slide open, there would be a mark on the bullet where it had jammed against the barrel, and the bullet would be pulled out the case by about 1\32", as evidenced by a slight circumferential mark on the case where it had been crimped. So what's going on? Is the recoil of the first shot popping the top bullet in the mag out of it's case, like a magnum revolver? Or is the round just too long to feed, and it's the effort of pulling the stuck bullet out of the barrel that's pulling it out of the case? I try to use a minimal crimp, but maybe I'm overdoing it even so. I tried running some of the finished rounds through a harder crimp, didn't help.

June 8, 2010, 08:57 AM	#3
Sevens Senior Member Join Date: July 28, 2007 Location: Ohio Posts: 11,756	Yes, the longer COAL rounds are too long for your particular barrel/chamber. Depending on the shape of the bullet (even FMJ round nose aren't all the same shape) some can be loaded further out than others. When the bullet of the chambered round contacts rifling the in the barrel so much that you can't close the slide and you see marks on the bullet when you eject it, that's your obvious sign that you need to reduce the COAL of the cartridge. As was said, the taper crimp merely re-sets the brass so that it can headspace properly, it's proper case mouth tension (set by the sizing die) that gives you bullet pull, not a crimp. It's important to not reduce the COAL by too much (as you reduce the internal space, the pressure rises) but you must also make ammunition that fits your pistol and in your case, those particular bullets will not run at 1.270" COAL. They run at 1.200" COAL (which is a common COAL for 230gr FMJ in .45) so try again at 1.200" COAL and if those work, stick with that COAL for those bullets. You are quite correct in that a harder crimp is NOT going to help you here in any way. __________________ *Attention Brass rats and other reloaders:* I really need .327 Federal Magnum brass, no lot size too small. Tell me what caliber you need and I'll see what I have to swap. PM me and we'll discuss.

June 8, 2010, 06:54 AM	#2
mongoose33 Senior Member Join Date: June 23, 2009 Location: Wisconsin Posts: 228	My guess: You're crimping too much, which is buckling the case a bit and reducing neck tension. The clue that leads me to this conclusion is the crimp ring you're seeing in the bullet after it sets forward. The .45 ACP needs only enough taper crimp to straighten out the expanded casemouth (what you're expanding to allow the bullet to enter the case and be seated). "Crimping" in a straightwall cartridge like this is an unfortunate use of the word, as it implies something necessary to maintain tension on the bullet. Normal neck tension is enough to hold the bullet. Your taper crimp should be just enough to straighten out the casemouth and square it up--nothing more. The .45 ACP headspaces on the casemouth; anything that starts turning that casemouth into the bullet risks doing it so much that it jams in the throat and causes you problems.

June 8, 2010, 06:14 PM	#4
Caboclo Senior Member Join Date: November 2, 2009 Posts: 212	Thanks guys.

June 9, 2010, 09:28 AM	#5
demigod Junior member Join Date: March 13, 2008 Location: AZ Posts: 1,129	Take a loaded round and drop it in the barrel. (with the barrel removed from the slide.) If the case doesn't sit flush with the barrel hood, the bullet is hitting the rifling. Sounds to me like you have the bullets seated way too long and they're lodging into the rifling and sticking when you go to eject them.

June 9, 2010, 09:50 AM	#6
m15171 Junior Member Join Date: April 20, 2009 Location: Albuquerque NM Posts: 2	i had the same problem with moly coated bullets from Precision. it has to do with the shape of the nose. once i set the oal to 1.20 they fed flawlesly

June 10, 2010, 12:31 PM	#7
demigod Junior member Join Date: March 13, 2008 Location: AZ Posts: 1,129	Indeed. The seating die usually indexes off of the bullet's ogive. Whenever you switch bullet makers, you should chamber check your first few rounds to avoid a whole run of problematic ammo.