What do you do when you buy a used gun?

[Aguila Blanca]

I recently bought a new alloy-framed, commander-sized 1911 and didn't notice until I got it home that the manual safety was a bit mushy (too easy to move on and off). I stripped it and found that the plunger spring was kinked,

That's a feature, not a bug.

Seriously. When removing the thumb safety from a 1911, if the plunger spring is straight the whole plunger and spring has a tendency to fly out ... there's still one somewhere under my basement workbench from about five years ago. Colt and maybe a couple of other smart manufacturers use the kink to help keep the plunger assembly in the tube, where it belongs.

I think the out-of-round tube was probably the cause of your problem.

 

[Gunplummer]

Odd that people do not worry about used police firearms. 30 or more years ago we had a cop shoot himself at a club range. I am not sure if he died, but I seem to remember he did. The investigation showed that he laid a loaded handgun on the table, started to walk down range, and the gun went full auto on him. Apparently he had "Smoothed out" the trigger pull with a stone and got carried away. Literally. As for me, I buy used guns all the time for parts and repair, so I am checking them out anyway. You should give it a once over. People do weird stuff to guns.

 

[Metal god]

I field strip and clean real well . If I don't know much about the firearm I'll go on youtube and see if there is any good info to be found . I recently inherited a 22 rifle from a relative ( forget the brand or model ) that was incredibly dirty . I field stripped it but the inerds looked way to complex to mess with so I just clean and cleaned until it was looking pretty good inside . I would have no idea if anyone had modified it or if parts were even missing .

I took it out and it worked OK but there was an interesting thing to this rifle . It's a semi auto tube fed firearm . When you pull the trigger it goes bang and cycles the bolt back ejecting the case like you'd expect . How ever if you hold the trigger back the bolt stays back and does not move forward loading the next round until you release the trigger . I had never seen that type of function before .

My buddy on the other hand bought a Remington 700 that had a pretty dirty trigger and I just learned may have been modified or even missing parts of the trigger . Him not knowing anything about the firearm just cleaned it and took it to the range . We quickly found that the gun would fire by simply closing the bolt sometimes . Instead of messing with it he just had a new trigger installed .

I was talking about this recently on a forum but not sure where ( likely here ) and was supposed to upload more pictures of the old trigger but never got around to it . I was told based on the pictures I did post that it might be missing a screw and maybe some other issue . That may explain why it had those failures . He bought from a gun store off the used rack . I would have thought they would have given it a good once over and maybe it did but it failed at the range with in 4 shots and I was able to reproduce the failure 4 more times so there was something wrong for sure .

 

[JohnKSa]

That's hard to envision as M&Ps have a plunger that blocks the striker unless the trigger is pressed (that is, the safety is deactivated not by the sear but by the trigger bar moving backward).

The gun was examined by a licensed forensics engineer with considerable firearms experience. He confirmed that the modifications would have allowed the gun to fire without the trigger being pulled.

Modifications which alter the trigger travel or trigger reset distance can disable passive safeties which depend on trigger movement.

I have a friend who "pins" the triggers on his competition Glocks. This dramatically reduces the trigger travel/takeup but, as a consequence, can have the unwanted side-effect of disabling the drop safety, the trigger safety and the firing pin block.

 

[Loosedhorse]

That's a feature, not a bug.

I thank you for that information; I did not realize that the spring may have been bent intentionally. However, whether that's a feature or a bug seems something for the user to decide.

For me on that particular pistol, the kinked spring made the manual safety too easy to move, thereby increasing the risk of moving it unintentionally. I don't want that.

Further, inspection of the kinked spring revealed that the high spot of the kink was nicely polished from rubbing on the inside of the tube. Those spring are thin; not sure I want one high spot always rubbing to give me a predictable point of failure.

I notice that neither Wolff nor Brownells sells pre-bent plunger springs. Technical drawings for the spring do not show any kink; the kink doesn't seem part of Browning's design.

the whole plunger and spring has a tendency to fly out

That's also true for the firing pin and its spring; yet I don't see anyone kinking that spring to "help". Same with nearly every spring in an AR-15. One simply controls the spring on disassembly.

Modifications which alter the trigger travel or trigger reset distance can disable passive safeties which depend on trigger movement.

I have a friend who "pins" the triggers on his competition Glocks. This dramatically reduces the trigger travel/takeup but, as a consequence, can have the unwanted side-effect of disabling the drop safety

Again, I appreciate the info. I note that some after-market triggers tout reducing take-up; if I ever use one, I'll remember to check whether it, in its resting position, has already displaced the safety plunger.

I would think that such a modification would be easy to spot, with the trigger far back from its usual position. (Disabling the drop safety by, say, removing the plunger would also be easy to spot.) The implication on the video was that the gun's modified sear had caused the no-trigger-pull discharge.

I am somewhat surprised that a gun with a disabled drop safety is allowed in competitions these days; perhaps I should not be.

 

[Jim Watson]

I am somewhat surprised that a gun with a disabled drop safety is allowed in competitions these days; perhaps I should not be.

It is against the RULES most places, but is actually checked only at major matches like Tier 3 or bigger IDPA.
I had to reinstall a Colt S80 firing pin obstruction when they got picky about it.

 

[rickyrick]

I check it out in the most thorough way I can before any ammunition goes with it. Function check in any way that I can, especially looking to make sure the only way that the firing mechanism releases is with a trigger pull.

First shots at the range are not for accuracy. I fire the gun with my body parts as far away as I can.

 

[SIGSHR]

Do the basic checks before I buy. If the trigger pull feels too light, the safeties don't work, too many signs of hot loads, I'll pass. Though I did get a good buy on my Walther P-38. The safety was "broken". Turned out the firing pin was broken. IIRC $5.00 for a new pin and a half hour's work restored it.
I recall Massad Ayood writing about a pistolsmith named Andy Cannon, he noted that until he mastered his trade any gun he worked on was to be avoided-he mentioned trigger pulls that were too slick, e.g.

 

[joe45c]

I usually disassemble them and do a thorough cleaning. In fact i just bought a Winchester model 1890 built in 1908. Took it apart and all the metal parts went into some hoppes #9 for cleanup.

 

[Loosedhorse]

For revolvers, one more thing...

Besides the regular function and safety testing, I look for screws that have been chewed up (by improper screwdrivers and lack of care) and, on Smiths, a warped seam where the sideplate meets the frame. Those signs indicate that someone's been inside the gun, he didn't know what he was doing, and he wasn't particularly concerned with what he messed up.

However, context matters. Messy screws on a Webley & Scott Mark V wouldn't bother me as much, for several reasons.

 

[peggysue]

I buy it after I research it. If on Gun Broker I take a chance and get it. Clean it research it again and maybe shoot it. I have a few boat anchors. Not a big deal.

 

[15plus1]

Recently bought a police trade in that, from the factory, was supposed to have a mag release safety it seemed to be disabled, or possibly never installed.

Every thing else looked fine with a field strip and slide racking. So I bought it.

 

[Sure Shot Mc Gee]

When I bought my first squeeze cocker I took it apart for curiosity. BIG mistake. Had to send it back to its factory to reassemble as most of the good gunsmiths in this area had never seen one before. > fully un-assembled<

Field strip is about all I will do these days. Only because sooner or latter I will need to learn how to dissemble >to a reasonable point< for cleaning purposes.

 

[Loosedhorse]

When I bought my first squeeze cocker I took it apart for curiosity. BIG mistake.

I think that's commonly called the "Bag o' Gun" problem: you start out with a functioning firearm, and end up with a bag o' gun parts to take (or ship) to a gunsmith.


Whenever a friend finally breaks down and buys his first Glock (if he was a 1911 guy), or his first 1911 (if he was a Glock guy), I invite him over and we have a Bag o' Gun Party: take it down to springs and pins; then put it back together again. Beers after the guns are put away.

Rule: no fair if you have more than three parts left over.

That being said, I've NEVER had a P7 party and won't unless I become a certified armorer for it. Even though I have the armorer's book.

(Sigh. With P7 parts so hard to get, I've mostly retired my P7. It was a great SD piece, but time moves on.)