1911 slide not locking after last round

Tex S · November 23, 2009, 12:10 AM

I have been loading 200gr LSWC over 5.3gr of W231. They function and shoot great. I just picked up some 185gr LSWC and loaded them with the same 5.3gr charge. The recoil is noticeably lighter and now the slide will not remain locked open after the last round. I thought this was strange since I am not using an extremely low powder charge, and we are only talking about a 7.5% decrease in bullet weight.

Do yall think this is out of the ordinary?

spleify · November 23, 2009, 01:47 AM

Did you try shooting any 200gr again after the malfunction with the 185's? It seems unlikely that the change in bullet grain would cause this but I suppose it is possible.

I would try asking this in the smithy forum, or even the semi-auto forum.

HTH

Good luck

rwilson452 · November 23, 2009, 09:17 AM

I could be the mag spring is weak.

Walkalong · November 23, 2009, 10:12 AM

If it is not locking back now it is the mag or the load is just a little to light and the slide isn't coming back (compressing the spring) all the way.

**Unclenick** · November 23, 2009, 10:33 AM

Yuppers to that. You've simply passed the threshold where the recoil spring needs to be lightened. You'll have noticed the recoil now feels mushier because the slide isn't getting all the way back to bang against the frame. If you hold the gun out with really stiff arms and an extra hard grip, the slide will probably stay back because you aren't letting the frame move under it as much. Not a comfortable way to shoot and it promotes shooter's elbow when you grip too hard.

This is a very common result from reducing bullet weight. People forget that not only has the bullet mass reduced, but with it, Newton's equal and opposite reaction force for the powder to build pressure against has reduced. As a result, even with the same powder charge, the gun is now throwing a lighter bullet using a lower peak pressure. It's that combination that cuts recoil disproportionately to bullet weight alone.

The .45 ACP was originally designed by Browning to use a 200 grain bullet. Development testing resulted in it being changed, but even though that was all done by the time the 1911 came along, I still find that gun has its broadest functional load energy range using the 200 grain bullet weight. It will let you go from a moderate target charge to hot +P and still operate the 5" 1911 with its standard 16 lb recoil spring.

November 23, 2009, 12:10 AM	#1
Tex S Senior Member Join Date: November 12, 2008 Location: Fort Worth, TEXAS Posts: 909	1911 slide not locking after last round I have been loading 200gr LSWC over 5.3gr of W231. They function and shoot great. I just picked up some 185gr LSWC and loaded them with the same 5.3gr charge. The recoil is noticeably lighter and now the slide will not remain locked open after the last round. I thought this was strange since I am not using an extremely low powder charge, and we are only talking about a 7.5% decrease in bullet weight. Do yall think this is out of the ordinary?

November 23, 2009, 01:47 AM	#2
spleify Senior Member Join Date: August 3, 2009 Location: Denver, Colorado Posts: 151	Did you try shooting any 200gr again after the malfunction with the 185's? It seems unlikely that the change in bullet grain would cause this but I suppose it is possible. I would try asking this in the smithy forum, or even the semi-auto forum. HTH Good luck __________________ ΜΟΛΩΝ ΛΑΒΕ NRA Member Survival Paracord Wraps & Bracelets Like us on Facebook

November 23, 2009, 09:17 AM	#3
rwilson452 Senior Member Join Date: June 10, 2004 Location: Tioga co. PA Posts: 2,647	I could be the mag spring is weak. __________________ USNRET '61-'81

November 23, 2009, 10:33 AM	#5
Unclenick Staff Join Date: March 4, 2005 Location: Ohio Posts: 21,063	Yuppers to that. You've simply passed the threshold where the recoil spring needs to be lightened. You'll have noticed the recoil now feels mushier because the slide isn't getting all the way back to bang against the frame. If you hold the gun out with really stiff arms and an extra hard grip, the slide will probably stay back because you aren't letting the frame move under it as much. Not a comfortable way to shoot and it promotes shooter's elbow when you grip too hard. This is a very common result from reducing bullet weight. People forget that not only has the bullet mass reduced, but with it, Newton's equal and opposite reaction force for the powder to build pressure against has reduced. As a result, even with the same powder charge, the gun is now throwing a lighter bullet using a lower peak pressure. It's that combination that cuts recoil disproportionately to bullet weight alone. The .45 ACP was originally designed by Browning to use a 200 grain bullet. Development testing resulted in it being changed, but even though that was all done by the time the 1911 came along, I still find that gun has its broadest functional load energy range using the 200 grain bullet weight. It will let you go from a moderate target charge to hot +P and still operate the 5" 1911 with its standard 16 lb recoil spring. __________________ Gunsite Orange Hat Family Member CMP Certified GSM Master Instructor NRA Certified Rifle Instructor NRA Benefactor Member and Golden Eagle Last edited by Unclenick; November 23, 2009 at 10:39 AM.

November 23, 2009, 10:12 AM	#4
Walkalong Senior Member Join Date: May 30, 2007 Location: Al. Posts: 196	If it is not locking back now it is the mag or the load is just a little to light and the slide isn't coming back (compressing the spring) all the way.