1911 Slide Failure To Lock On Empty Mag

BradS · January 5, 2020, 04:22 PM

I purchased a Dan Wesson Vigil 9mm and made a trip to the range.
I only put a bit more than 100 rounds down the tube, but after about halfway in , the slide would fail to lock back on an empty magazine.
With this one exception the pistol ran great, smooth shooting and accurate.
I went home, cleaned and oiled the pistol and duplicated the issue when racking the slide with an empty magazine.
I took a second look at the pistol today and when I slowly racked the slide the slide stop would engage, but not completely.
I don't know if this is related, but a good bit of pressure is needed to engage the safety.
Any ideas on how to remedy this issue ?

krunchnik · January 5, 2020, 07:51 PM

New or used Dan Wesson-magazine springs possibly week not allowing the slide stop to fully rise-possibly defective magazine.
Most of the time when a 1911 will not lock open on last round it is due to a magazine fault.

BradS · January 5, 2020, 11:08 PM

I utilized my Springfield Range Officer magazines with the DW and experienced the same failure to lock back.

**Aguila Blanca** · January 7, 2020, 11:04 PM

If you insert an empty magazine into the frame with the slide and barrel removed, so the slide stop move up freely? With the slide and barrel installed but the recoil spring either not installed, or left slack, does the slide stop move up freely when pushed up manually?

You're looking for what would appear to be an interference fit. The trick is to isolate where the interference is, and then file something down to relieve it.

bamaranger · January 8, 2020, 12:17 AM

I'd try a couple of other mags before I started to file. What's to say the Springfield mag is weak as well, but the Springfield pistol works with it anyhow, for what ever reason.

DnPRK · January 8, 2020, 01:51 AM

Is the pawl on the slide release long enough to engage the magazine follower? Take off the slide. Install the slide release and insert a few magazines. Look to see how much engagement the pawl has with the followers.

Scorch · January 8, 2020, 04:04 PM

I see this fairly commonly, factory 9mm 1911s that will not consistently lock back. 9mm and 38 Super slide stops have a longer latch extension than 45s. Buy a 9mm slide stop.

**4V50 Gary** · January 10, 2020, 07:35 PM

I'd try Colt factory 9mm mags. See if you can borrow one.

Had a PD guy who carried a 1911 with Wilson mags. He had problems and once USGI mags were tried, it was flawless.

**44 AMP** · January 11, 2020, 01:41 AM

strip the pistol enough to remove the slide stop plunger and plunger spring (this will also remove the safety plunger).

Reassemble the gun enough to be able to work the slide with the slide stop in place without any tension on it. Insert the "defective" magazine and see if the slide will lock back. If yes, then you can discount the plunger tension as the problem. But if it fails to lock open, then your problem is the plunger and its spring tension.

Some guns just have the plunger pushing on a flat face on the slide stop. Others have a "dimple" in the slide stop for the plunger to ride in. These can be stiff, especially on a new gun. Also look at the plunger tip, itself, it should be smoothly rounded, without anything to cause drag.

Same check for a "stiff" safety. Seldom the cause but can be. Simple check to confirm or eliminate as a possible cause.

good luck

Henry400 · June 5, 2020, 10:02 PM

Dan Wesson manual states that they need a 500 round break-in period. During this period, shoot only roundnose ammo, and don't clean the gun. Just lube it every 100 rounds, especially the slide rails and the barrel lugs, and up by the bushing. Don't clean off the old lube, just ad more. The tolerances in a DW are really tight, and the oil/grease mixed with powder residue acts like jewelers' rouge and polishes bearing surfaces. After 500 rounds, clean it, oil it, and you're good to go.

January 5, 2020, 04:22 PM	#1
BradS Senior Member Join Date: July 8, 2005 Location: Salisbury,Pennsylvania Posts: 173	1911 Slide Failure To Lock On Empty Mag I purchased a Dan Wesson Vigil 9mm and made a trip to the range. I only put a bit more than 100 rounds down the tube, but after about halfway in , the slide would fail to lock back on an empty magazine. With this one exception the pistol ran great, smooth shooting and accurate. I went home, cleaned and oiled the pistol and duplicated the issue when racking the slide with an empty magazine. I took a second look at the pistol today and when I slowly racked the slide the slide stop would engage, but not completely. I don't know if this is related, but a good bit of pressure is needed to engage the safety. Any ideas on how to remedy this issue ? __________________ Then I heard the voice of the Lord saying, "Whom shall I send? And who will go for us?" And I said, "Here am I. Send me!" Isaiah 6:8

January 5, 2020, 07:51 PM	#2
krunchnik Senior Member Join Date: October 27, 2010 Location: Lakeland,TN Posts: 220	New or used Dan Wesson-magazine springs possibly week not allowing the slide stop to fully rise-possibly defective magazine. Most of the time when a 1911 will not lock open on last round it is due to a magazine fault. __________________ THE CROW

January 5, 2020, 11:08 PM	#3
BradS Senior Member Join Date: July 8, 2005 Location: Salisbury,Pennsylvania Posts: 173	I utilized my Springfield Range Officer magazines with the DW and experienced the same failure to lock back. __________________ Then I heard the voice of the Lord saying, "Whom shall I send? And who will go for us?" And I said, "Here am I. Send me!" Isaiah 6:8

January 7, 2020, 11:04 PM	#4
Aguila Blanca Staff Join Date: September 25, 2008 Location: CONUS Posts: 17,811	If you insert an empty magazine into the frame with the slide and barrel removed, so the slide stop move up freely? With the slide and barrel installed but the recoil spring either not installed, or left slack, does the slide stop move up freely when pushed up manually? You're looking for what would appear to be an interference fit. The trick is to isolate where the interference is, and then file something down to relieve it. __________________ NRA Life Member / Certified Instructor NRA Chief RSO / CMP RSO 1911 Certified Armorer Jeepaholic

January 8, 2020, 12:17 AM	#5
bamaranger Senior Member Join Date: October 9, 2009 Location: North Alabama Posts: 7,904	try I'd try a couple of other mags before I started to file. What's to say the Springfield mag is weak as well, but the Springfield pistol works with it anyhow, for what ever reason.

January 8, 2020, 01:51 AM	#6
DnPRK Senior Member Join Date: August 24, 2001 Location: LC, Ca Posts: 1,916	Is the pawl on the slide release long enough to engage the magazine follower? Take off the slide. Install the slide release and insert a few magazines. Look to see how much engagement the pawl has with the followers.

January 8, 2020, 04:04 PM	#7
Scorch Senior Member Join Date: February 13, 2006 Location: Washington state Posts: 15,188	I see this fairly commonly, factory 9mm 1911s that will not consistently lock back. 9mm and 38 Super slide stops have a longer latch extension than 45s. Buy a 9mm slide stop. __________________ Never try to educate someone who resists knowledge at all costs. But what do I know? Summit Arms Services Last edited by Scorch; January 8, 2020 at 04:14 PM.

January 10, 2020, 07:35 PM	#8
4V50 Gary Staff Join Date: November 2, 1998 Location: Colorado Posts: 21,647	I'd try Colt factory 9mm mags. See if you can borrow one. Had a PD guy who carried a 1911 with Wilson mags. He had problems and once USGI mags were tried, it was flawless. __________________ Vigilantibus et non dormientibus jura subveniunt. *Molon Labe!*

January 11, 2020, 01:41 AM	#9
44 AMP Staff Join Date: March 11, 2006 Location: Upper US Posts: 26,797	strip the pistol enough to remove the slide stop plunger and plunger spring (this will also remove the safety plunger). Reassemble the gun enough to be able to work the slide with the slide stop in place without any tension on it. Insert the "defective" magazine and see if the slide will lock back. If yes, then you can discount the plunger tension as the problem. But if it fails to lock open, then your problem is the plunger and its spring tension. Some guns just have the plunger pushing on a flat face on the slide stop. Others have a "dimple" in the slide stop for the plunger to ride in. These can be stiff, especially on a new gun. Also look at the plunger tip, itself, it should be smoothly rounded, without anything to cause drag. Same check for a "stiff" safety. Seldom the cause but can be. Simple check to confirm or eliminate as a possible cause. good luck __________________ All else being equal (and it almost never is) bigger bullets tend to work better.

June 5, 2020, 10:02 PM	#10
Henry400 Member Join Date: December 16, 2019 Location: Cowtown, USA Posts: 44	Dan Wesson manual states that they need a 500 round break-in period. During this period, shoot only roundnose ammo, and don't clean the gun. Just lube it every 100 rounds, especially the slide rails and the barrel lugs, and up by the bushing. Don't clean off the old lube, just ad more. The tolerances in a DW are really tight, and the oil/grease mixed with powder residue acts like jewelers' rouge and polishes bearing surfaces. After 500 rounds, clean it, oil it, and you're good to go.

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