Bad trigger job by a pro.(long)(ranty,too)

[model 649]

Evening all, I just need to vent a little . 3 weeks ago I dropped off my Smith 745 at my local shop so their well-recommended gunsmith could reduce the trigger pull from just over 6 lbs. down to, ideally, 4 lbs. I was on my way home from shooting three pin matches and man, my finger was aching. I do the work on my 1911 with great success, but the Smiths are more like a watch to me so I figured I'd let a professional go into it (some jobs are best left to professionals). Well they called today and I went down to pick it up and part with $50.00, which, if the job was right, is money well-spent to me. The 'smith was already gone for the day and one of the clerks went and got it for me. I started dry-firing it to check out the trigger and immediately noticed that the hammer was rebounding and catching the half-cock notch every time. I said "I haven't had this gun long, but I don't remember seeing that before". (I didn't even know it had a half-cock notch)(I've never seen a hammer function like this on any of my guns, ever). The clerk said "oh, yeah, thats a safety function". I thought "hmm, so it's supposed to work this way and the 'smith fixed it?" Nah, it still didn't seem right. The gun doesn't even have a firing pin block, why would it do that? The hammer felt light as I cocked it, but I haven't handled it in 3 weeks. I did replace the recoil spring when I bought it, as well as the hammer spring, and firing pin spring with new Wolffs as the gun was made in 1987 and they looked to be original. This whole thing seemed wrong. The hammer spring, as far as I know on 1911's effects the unlocking of the slide and this hammer bouncing back seemed, to me, bad for unlocking, as in speeding it up. When I got home I went down to the bench to have a look at that hammer spring. Yup, you guessed it, the 'smith had ground a little more than an eighth inch off one end. (I knew it was ground because it was blue and flat).(Aren't springs supposed to be clipped, not ground, anyway?) I took out a new-in the package spare spring and saw that the wire is round, not flattened at either end, and longer. Now, I realize that shortening springs is not uncommon when tuning a gun, but if the spring needed lightening, Wolff sells these springs far lighter than factory, why not use one of those? So I put the old original spring back in and sure enough, the hammer goes down and stays down against the slide the way I thought I remembered it did. :banghead: Three weeks and fifty bucks later I get a malfunctioning pistol back! I got on the phone and explained that I really wanted to meet the 'smith and discuss this problem with him in person. I'd like to know if (1) he's ever worked on one of these pistols, and(2) has he ever seen any other Browning system pistol rebound the hammer to half-cock as a regular function. I'm no 'smith, but in my work, I just about always know when it's right or not when I finish, before it goes out to the customer. I'll see the 'smith Monday. I don't know really what I want from him(a $4.00 spring?) The trigger does feel better(even with my new spare spring in it) (my scale is across town at the moment, so I can't measure for sure). I think he was actually inside the frame smoothing things, so at least some of the work is there for the money, just that rebounding hammer that he should have seen really burns me, I guess. I'm sure the firing would be erratic at best. I guess, maybe, I would have liked to have been told that 4 lbs. was unachievable while preserving the function and I'd have left it at that. Thanks for letting me blow off a little steam here. I'd really like this gun to run well and I've been working at it hard enough without a crappy job from a professional to set me back.
Josh

 

[BluesBear]

Let me make sure I got this right.

After the hammer falls from firing, the pressure of the firing pin spring pushing the firing pin back into position is stong enough to bring the hammer to safety cock?

If that's what you're saying.




IT AIN'T RIGHT!
The hammer should fall and stay all the way down until the slide moves and pushes the hammer to full cock.
If it can "bounce" back to safety cock that means that only inertia is causing the hammer to impact at all.

I'll wager that the spring has little or NO tension at rest because the spring is now too short.
I'll also wager that you will get misfires out the wazoo if you attempt firing it.

With the butchered mainspring in the gun, do the pencil test.

Make sure the gun is unloaded.
Get a red #2 pancil with an unused eraser.
Make sure the gun is unloaded.
If you don't have a red #2 pencil use a light blue one.
Make sure the gun is unloaded.
If you can't find a light blue one try to locate one of the rare yellow ones.
Make sure the gun is unloaded.
Insert the bencil into the bore eraser first.
Make sure the gun is unloaded.
Point the pencil toward the ceiling.
Make sure the gun is unloaded.
Cock the hammer,
Pull the trigger.
Notice how high the pencil goes.

Now put in the original spring and repeat the procedure after you make sure the gun is unloaded.

If the butchered spring doesn't launch the pencil AT LEAST as high as the original spring, IT'S DEFECTIVE.

But probably not nearly as defective as the brain of the quack who "fixed" it.

 

[model 649]

Yup, Bluesbear, The hammer bounces off the firing pin and catches the half-cock.....every time. I won't try to fire it (why bother). The 'smith is supposed to be in the shop on Monday. I'll show him how it works now and also how it should work. I still have a hard time believing he thought this was O.K. Thats the part that burns me the most. I could have messed my gun up myself for alot less money. I'll post back on Monday after I meet this guy.
Josh

 

[bountyhunter]

I'll wager that the spring has little or NO tension at rest because the spring is now too short.
I'll also wager that you will get misfires out the wazoo if you attempt firing it.

Bullseye.

 

[Jim K]

Hi, Model 649,

The problem seems to be amenable to an easy solution, but where did anyone get the idea that "The hammer spring ... on 1911's effects the unlocking of the slide". I am not sure whether you mean "effect" or "affect", but the hammer spring certainly does not cause the unlocking, and has negligible effect on it. There seems to be a common belief that the hammer spring somehow converts the 1911 into a delayed blowback or something like that, and that the hammer spring plays a significant role in the functioning of the pistol.

Yes, if you made a hammer spring (mainspring) very strong, or blocked the mainspring channel entirely, the slide wouldn't come back, but then the hammer couldn't be cocked either. Any reasonable mainspring weight will have no significant effect on the recoil of the slide, one reason being that the recoiling slide almost immediately kicks the hammer out of contact, so the hammer is not even touching the slide between the first movement and the time the slide is over an inch back.

Jim

 

[model 649]

Jim, that was a thought that came out of other threads here dealing with 1911's. As this pistol operates on the same principles, I connected them. So, you're saying that the hammer doesn't provide any delay in the first movement of the slide rearward? That is, the hammer spring isn't absorbing energy as it forces the hammer back? I was thinking it did affect the unlock timing and not having the hammer against the slide would be detrimental. O.K. I could be and have often been wrong. In any case, yes, I know this can be corrected simply(I already have). The complaint is that I left a functioning gun with a gunsmith and received a malfunctioning gun in return. The man ruined a new, albeit inexpensive hammer spring in the process and these things together make me question the rest of the job. I usually do my own work. I usually know when I am in too deep and look for help. This guy does alot of work in our area and I talked to a few people I know who said they were happy with work he had done for them. Live and learn.
Josh

 

[mete]

What Jim is saying is that while the hammer spring does absorb energy of the slide moving rearward it isn't a significant amount.....BTW The bullet has left the barrel before there is any significant movement of the slide.Recoil that you feel almost entirely occurs when the slide hits the frame at it's most rearward point of travel.

 

[BluesBear]

You know, a lot of people on this forum could benefit immensely by taking high school Physics 101.

 

[Jim K]

OK, a bit of physics 101. Recoil of any firearm begins at exactly the same time as the bullet starts moving (Newton's law of conservation of momentum, Physics 101). Note that "the bullet starts moving". If the bullet does not move, there is NO recoil. Gas pressure in the chamber will not cause recoil since its force is exerted in all directions (Boyle's Law, Physics 101), only forward movement of mass will cause movement of mass in the opposite direction (Newton again). If the barrel is blocked so the bullet cannot move, there is NO recoil. (There is some recoil with a blank because there is forward movement of mass - the gas and burning powder - but that movement is not enough to function a recoil operated pistol.*)

In a recoil operated pistol (like the 1911, Luger, M9, Glock, P.38, etc.) the barrel and breech (slide in the 1911) are locked together, as a unit, until the bullet leaves the barrel, but recoil motion begins when the bullet begins to move. So the gun is actually in recoil while the bullet is still in the barrel. This recoil motion is compensated for by the sights.

As to the hammer, I didn't say that the resistance of the hammer to the rearward movement of the slide had no effect in retarding the slide. I said that in the overall picture, that retardation is not significant, and certainly does not "lock" the pistol or keep the breech closed.

What does keep the breech closed in the 1911 until pressure drops, is the upper lugs of the barrel locked into the lug seats in the slide. And, contrary to some nonsense that has been written, the barrel and slide really are locked together. If the barrel and slide unit is removed from the gun and clamped in a vise, and a round fired by driving the firing pin with a punch, the barrel-slide unit will try to recoil, but it will NOT unlock.

The barrel is unlocked from the slide only when unlocking is allowed. This is when the lower lug moves back from the slide stop pin. Even that won't actually unlock the barrel from the slide; it takes the link to do that. Once the link pulls the barrel down, and unlocks it from the slide, the slide continues back on momentum, bounces off the flange of the guide rod, and flies forward to pick up a round from the magazine and return the barrel to battery. It is this forward slide movement that is the main purpose of the recoil spring, not slowing the slide or acting to retard it. The gun will fire and unlock without a recoil spring, and the slide will even partially return to battery, but the recoil spring ensures the full return.

As to the hammer, when the slide starts back, one of the first things it does is hit the hammer a hard, fast blow, not a "push" as the pictures usually show. The hammer acts like a baseball struck by a bat. It moves down and back, out of contact with the slide, until it bounces off the grip safety. Then it returns at high speed to strike the bottom of the slide. This is the cause of the dent seen on the bottom of the firing pin tunnel on many 1911 pistols. The hammer spring alone would never be able to cause that dent; only the rebounding of the hammer with momentum remaining from its initial blow by the slide could make the mark. The dent is well forward of the firing pin stop because that is the distance the slide has moved since striking the hammer. During that time, the hammer has been out of contact with the slide.

I realize this is not what the pictures in books show, but high speed photos tell a different story. (The "dent", BTW, will be more noticeable, and closer to the firing pin stop, when "hot" loads are used, since the rearward hammer momentum is greater and more is left after rebound; the rebound is faster, so the dent is closer to the rear.) Firing a number of loads of different power will result in several dents, corresponding to the power of the load.

* High speed rearward movement of hot gas is enough to cause recoil though, if there is enough gas to provide lot of mass. A rocket works because the gas moving rearward causes the rocket to move forward. Unlike a gun, the recoil is continuous as long as the gas is moving. So, though we don't usually think of it that way, men went to the moon on recoil (Physics 101 again).

And that is why a rocket works in space; it doesn't need air to "push against", any more than a gun's recoil depends on the bullet pushing on the air.

Jim

 

[model 649]

Jim you could teach this stuff! Even I understood it (and thats saying something). So, then, that long thread dealing with the small radius firing pin stop on a 1911 is mostly, well, not what it seemed? There isn't a meaningful delay of the slide's movement, eventually resulting in less muzzle rise? That whole saga made sense to me, at least the part about delaying the slide a "tick" longer, allowing barrel pressure to drop a bit further while absorbing a significant amount of recoil energy into the hammer spring, ending up with less perceived recoil and muzzle rise. I myself, didn't notice a difference on my 1911 with that set-up, but what do I know? I was mostly interested in making the gun function closer to the way it was originally designed. With my 745, which operates on the same principle, I figured the rebounding hammer to cause faster slide movement being off the slide altogether. Talk about over-analyzing! I really like the gun and it competes well in my game, so, I got even more worked up when I found it was messed up by a pro, setting me off in print. Thanks Jim!
Josh

 

[Jim K]

I didn't get into that discussion because I have not tried that firing pin stop and so I really didn't feel I could comment. By lowering the contact point on the hammer, the mechanical advantage of the cocking motion is lessened slightly, because the lever arm is shorter. But IMHO, the difference is still insignificant, and I think the claimed advantages of lessened recoil, etc., are mostly subjective. I note that no one says they have put the gun on any kind of test rig to actually measure recoil, only that they claim to have "felt" less recoil. A double blind test (literally, with blindfolds) might be interesting.

One person who seems to be promoting it not only claims a reduction in recoil but also says that it prevents the hammer from striking the grip safety. But here also he did not indicate that he ran any real tests (using Dykem blue or another means of actually checking contact), only that his grip safeties are never marked by the hammer due to his expertise in setting up his guns, etc. Some folks have been skeptical.

(Why the hammer striking the grip safety seems to be a major concern for some folks escapes me. It is perfectly normal.)

Barring some better evidence, I remain "from Missouri." I would like to see high speed photos or at least some objective testing by someone who is not involved with the seller of the product.

Another fad item, which I will say flatly is useless, is the full length guide rod. If made of steel, it adds some weight to the gun and thus reduces recoil, but I can see no other use for it except to make money for the promoters and make the gun more difficult to disassemble. The idea that the recoil spring must be kept straight sounds good, but seems to have escaped the Army, John Browning, Colt, and quite a few folks over the years, all of whom thought the gun worked perfectly OK with the normal spring guide.

Jim

 

[bountyhunter]

but where did anyone get the idea that "The hammer spring ... on 1911's effects the unlocking of the slide".

It is commonly taught that going to a lighter hammer spring can allow faster unlock. On some of the guns that started out as 9's and had 40's made (like the Browning HP) rapid unlock would sometimes cause "primer wiping". That was due to the gun unlocking and starting to eject the round before the firing pin had fully retracted. A stronger hammer and firing pin spring was the fix.

As to exactly how much effect the hammer spring has on unlock times? Don't know. Maybe not much. The stroger firing pin spring will get the FP back faster, but also requires a stronger hammer spring to maintain good striking energy.

 

[bountyhunter]

Recoil that you feel almost entirely occurs when the slide hits the frame at it's most rearward point of travel.

For the record, I have seen actual "g-force" graphs (rearward force versus time) plots for various guns and the main recoil force is at the start of the cycle (instant of ignition) for both autos and revolvers.

The difference is, for a revolver there is only one (high and narrow) recoil pulse, but for autos there are two pulses: the first one at firing is a higher, the one when the slide hits the frame is lower, and there is a gradual "ramp rise" of force in between as the recoil spring compresses.... but the recoil force caused by this spring compression is not even 1/2 as tall as the initial pulse from firing.

Open gun shooters lighten their recoil springs to try to "equalize" the height of the two recoil pulses of their autos. The slide/spring assy acts as a recoil absorber, which means it spreads out the recoil energy over time and thereby reduces the peak amplitude. By getting the two pulses (firing and frame impact) more equal, the muzzle rise is minimized.

An interesting byproduct of all this is that revolvers "sight in" with their bores aligned a good bit lower than autos (with repect to the sight line). Revos have the bigger single recoil pulse (ignition) which causes the barrel to rotate upward faster and so the bullet leaves the muzzle a shade higher in the recoil arc.

I have a laser bore sighter and verified that every wheelgun I own sights in with the bore line at least a couple of inches under sight line at 17 yards when it is "zeroed" on target but the autos are close to "on line" comparing bore line to sight line (maybe 1/2" below). The recoil absorber effect of the slide assy is enough to reduce muzzle rise rate significantly.

 

[model 649]

I saw the gunsmith today after work. He claims that my gun was acting up BEFORE he started work on it. Apparently, he has never seen, much less worked on a 745. He said he did the "pencil test" and when he did, the pencil would shoot out and the hammer stayed down. He decided this was a "safety thing" unique to these guns. He also told me that as he had never seen one of these, he hoped it would be like a 1911 internally. I just stood there kind of dumbfounded. I thanked him for his time and forgave him in my mind as I left the shop.
Josh

 

[Jim K]

Hi, Bounty Hunter,

That quick fix with a heavier hammer spring may have solved the problem for the 9/40 change, but the real solution would have been to prolong the dwell time of the camdown. Since that would have involved some serious rework of the gun, the "quick and dirty" method was chosen; I still say it is not very significant, but it may have been just enough. I guess "what works, works" but the price would be paid in harder manual cocking and more strain on the hammer notch and sear. There is no such thing as a free lunch.

On the sights, the fact that recoil takes place while the bullet is still in the barrel causes barrel time to become a factor in sighting in a gun, particularly a handgun. A fast bullet will get out of the barrel earlier than a slower bullet. This means that if a handgun is sighted in for a relatively slow, heavy bullet (say 158 grain .38 Special) and then fired with a light, fast bullet (110 grain), the fast bullet will strike lower. The reason is that the barrel at firing is pointing downward, even though the sight line is horizontal. The faster bullet gets out of the barrel earlier, while the barrel is still in a low position, and so the bullet strikes lower.

There is an amusing story about the effects of barrel time. When police went from the 158 grain .38 Special bullet to the lighter and faster 125 grain, they found that their shots were striking the silhouette target considerably lower than they were used to seeing. Some range officers explained this by saying that police officials had decided to use ammunition that would castrate criminals, as that would be considered a worse punishment than merely killing them. The story was widely believed in police circles.

Jim

 

[pauli]

OK, a bit of physics 101. Recoil of any firearm begins at exactly the same time as the bullet starts moving (Newton's law of conservation of momentum, Physics 101). Note that "the bullet starts moving". If the bullet does not move, there is NO recoil. Gas pressure in the chamber will not cause recoil since its force is exerted in all directions (Boyle's Law, Physics 101), only forward movement of mass will cause movement of mass in the opposite direction (Newton again). If the barrel is blocked so the bullet cannot move, there is NO recoil.

nitpick - if the charge goes off but the bullet doesn't move, there's probably gonna be a whole lot of recoiling going on when the primer blows out and the angry gasses inside make there way out in the direction of the shooter

 

[BluesBear]

If the barrel is blocked so the bullet cannot move, there is NO recoil.

Correct.
Which is why there no recoil when a squib load is fired.

And it's also why a semi automatic pistol will NOT eject the empty case of a squib load.

 

[Hawk]

Couple of decades back I dropped off a Ruger Security Six for some much needed help on the trigger.

Picked up the guy after a week, paid IIRC, around 75.00, marched off to the range and had 4 ignition failures out of 6 (fortunately no hang fires - didn't know what that was back then).

Disassembled the Ruger and found no polishing. In fact, couldn't see where anything had been done - apart from the hammer coil spring being about 5 coils short of what I remembered. Hmmm, 75.00 for 20 seconds work with a pair of wire cutters.

Mercifully, that shop is out of business.

 

[bountyhunter]

Disassembled the Ruger and found no polishing. In fact, couldn't see where anything had been done - apart from the hammer coil spring being about 5 coils short of what I remembered. Hmmm, 75.00 for 20 seconds work with a pair of wire cutters.

That pretty much defines "butcher".

 

[Jim K]

Pauli wrote:

"nitpick - if the charge goes off but the bullet doesn't move, there's probably gonna be a whole lot of recoiling going on when the primer blows out and the angry gasses inside make there [sic] way out in the direction of the shooter"

Well, no. I have blocked the barrel of a 1911 in such a way that the bullet could not move or compress. When a full charge (GI) load was fired, nothing happened except a sort of "thunk" from the primer and a hissing sound as the gas escaped slowly around the case. No blown up gun, no damage to the shooter. And no recoil. A strain gauge was placed across the gap between the slide and frame; it showed no movement. The primer can't blow out because it is held in the way it always is - by the breechblock.

WARNING: That experiment was done under controlled conditions, in a containment box. Allowing the slide to move enough to unlock will result in a burst case and damaged gun, with the possibility of personal injury. In other words, DO NOT TRY THIS AT HOME!

Jim