1911 failure to feed last round cause?

[7.62 Solution]

I would really appreciate any ideas as to why my 1911 fails to chamber the last round from the magazine. With different magazines the pistol will leave the final round unchambered with the slide locked back. The cartridge is left sitting above the magazine and the pistol is locked open as if it's empty. Ideas and thoughts as to the cause are appreciated.

 

[Drail]

Inertial feed. The last round is being jerked out of the case by inertia before the extractor can pick it up. A new magazine spring will usually fix it. The reason the old G.I. spec mag followers have that little dimple stamped on them is to prevent this problem. The dimple will hold it in place. If you don't know how old your mag springs are, change them.

 

[1911Tuner]

What Drail said. Essentially, the cartridge is jumping the magazine when the slide impacts the frame, letting the follower engage the slide stop. An overly-heavy recoil spring can be a contributor, as can a smooth-topped follower. That silly little dimple on top of the follower in the 7-round magazine was put there for a very good reason. So many people who market magazines are either ignorant of that...or they choose to ignore it. That Browning feller really did know what he was doin'.

 

[Drail]

I think Browning was from another planet just like Leonardo DaVinci. Every time I tear down a Browning design I have to just look at it and marvel at how his mind worked.

 

[1911Tuner]

Yep, Drail. Browning not only had a penchant for designing one part to perform multiple functions...he was the master of redundancy. There was always a backup in case the primary failed. Functional reliability was his mantra. All else ran a distant second.

 

[7.62 Solution]

Gentlemen, thank you for the information and the instructions. I will buy a new magazine or replace the springs and report back with the results. I agree about Browning, I have read more about his designs than actually used/disassembled them, but to think he came up with the ideas and made them work so long before CAD animation, high speed camera analysis and cnc prototyping is simply amazing. Thanks again for sharing your knowledge.

 

[Fishslayer]

An overly-heavy recoil spring can be a contributor, as can a smooth-topped follower. That silly little dimple on top of the follower in the 7-round magazine was put there for a very good reason.

IIRC it was your posts that led me to the Checkmate dimpled 7 rounders w/heavy springs & hybrid lips?

Then there is this of course... from The Gospel According to JMB...

And the profaning of the internal parts didst render it unworkable when the dust of the land fell upon it, and these profaners didst try and fit more rounds of ammunition into the magazines than the holy number of seven, appointed for the .45.