Topic: Hammer Strut mod (Read 6794 times)

Kilibreaux · « **Reply #60 on:** January 16, 2012, 06:42:22 PM »

Unfortunately that is the case with the FACTORY setup which I pointed out way back when I first presented the modifications.
You see, in a STOCK GSG when you pull the trigger that large plate on the left side is moved forward to depress a plunger that unlocks the firing pin...problem is, as long as you hold the trigger, the firing pin block is "unlocked" throughout the bolt's cycle.
in the FACTORY configuration if you retract the bolt ALL THE WAY BACK to where you just feel it touch the cocked hammer, then pull the trigger...what do you think will happen? The hammer will drop and this with the bolt approximately 2/3'd OPEN...this is how the GSG comes direct from the factory, so the mod to eliminate the relatively pointless firing pin block located in the bolt is completely valid. Whether you disconnect the block or not, as long as a FINGER is holding the trigger back - or pulls the trigger and the bolt is far enough forward so the cocked hammer is uncovered by the bolt, the hammer WILL FALL....factory or modded.
Now, what keeps the cartridge from firing is the ANGLE formed between the hammer and bolt IF the bolt is out of battery....IF the breech was "half open" with a jammed cartridge and the trigger pulled, the hammer cannot reach the firing pin. This is a part of modern "safe design" and is what REALLY prevents an out of battery fire...UNLESS, as you stated the gun is "really dirty" which might have lead to a "slam fire" from a bound up firing pin that hangs up at just the right point so the cartridge rim can get in front of it, yet protrudes just enough - maybe .020" to cause a slam fire just as the breech closes.
22's have a hard time detonating the priming compound in any position other than chambered because the rim must be "crushed" and without a fixed point supporting the rim, even if the firing pin snaps forward inadvertent detonation is unlikely.

You did not specify precisely what happened when the trigger was pulled and the gun when "pop." Does this mean you had an out-of-battery fire and case rupture? You did not state that the gun was damaged in any way...this means no out-of-battery fire.

BTW, the whole POINT of doing the hammer strut mod is to CORRECT a major design error where the hammer has no direct spring impetus during the last 10 degrees or so of its travel which means when the gun fires the only force closing the breech is the bolt's mass and recoil springs until the bolt has moved back about 1/4"...which CAN and has led to case rupture due to the case being pushed out of the chamber during the high pressure phase. By modding the hammer and removing the "rebound" feature the bolt hits home under full spring pressure thus supplying important resistance to the breech opening.
The "features" deactivated on the GSG are completely unnecessary and create no more potential for a dangererous fire condition - practically speaking. Yes, IF the bolt lock is retained and the hammer slips the sear without a finger on the trigger, the hammer will not detonate the round, but if a finger is holding or has pulled the trigger and the bolt is closed or very close to fully closed the gun will fire.

It might be nice to see photos of any damage to better assess what happened.

dizzny1 · « **Reply #61 on:** January 17, 2012, 08:34:50 PM »

hold up real quick I wasnt saying anything about the hammer strut mod or the trigger reduction we worked out or anything like that, I should have been more clear and for that I apologize. The gun had aprox 400 rounds through it that day alone, so yes it was dirty. when the weapon misfed, it had the next round (the one that went off with the bolt open) already in the bolt (how that happened I have no idea) it looked like she chambered it, pulled the bolt halfway open, then pulled the trigger. This did not happen as I was watching her shoot from the left side, so I couldnt see that the breech was half open. I am sure it was a freak occurrence, My concern is that the weapon fired ie. the firing pin was released with the breech open with a pull of the trigger. Is there any way to make this weapon not fire unless the breech is fully closed? I beleave that would prevent this kind of occurrence from happening again (the firing part I mean) I will cycle check and snap cap the hell out of it to figure out why it misfed. No disrespect intended, just need a little help from the pro

Kilibreaux · « **Reply #62 on:** January 20, 2012, 01:24:28 AM »

Okay....let's see if we can figure this out.

In order for the hammer to depress the firing pin, the bolt MUST be virtually "closed." If you visualize the bolt retracted even a few millimeters, the hammer cannot strike the firing pin with enough force to fire a round. IF the bolt is open a greater distance, the firing pin is no longer a factor in any round that fires because it is nowhere near the firing pin.
UNLESS the bolt hangs up during feeding - "just enough" to that when the trigger is pulled the falling hammer's energy drives the bolt closed and smacks the firing pin - but there is a problem, and I assure you I've tested this...
The GSG has a MONSTER firing pin return spring. Even if you remove the entire trigger group and allow the hammer to ride the bolt home, the gun will not fire. What this means is the likelihood of the hammer causing a cartridge detonation is nil. However, if the firing pin opening has ingested enough carbonaceous material to cause binding, the firing pin MIGHT....MIGHT snag just enough that a suddenly driven forward bolt would result in a slam-fire.
Bear in mind a slam-fire only requires about .020" of firing pin protrusion which is about half what we normally expect from a hammer-fired system.
Another thing that might have caused this is retained debris...remember, .020" is TINY which means a few particles of grit...perhaps a buildup, could create, in effect, a fixed firing pin slam-fire situation. Based on the information you have supplied this scenario, or the scenario of a firing pin not properly retracted is the only explanation that is mechanically possible.

Is there a way to prevent this? The only way I can imagine is to check the chamber and bolt face frequently and spray it down with a solvent to clear out any grit (bearing in mind the gun's finish).

In RE-reading your last response I am more likely to conclude that regardless of what the shooter "appeared" to do, the end result was a closed breech for the following reasons:
1. The firing pin CANNOT be impacted by the hammer if the bolt is more than about .050" out of battery.
2. If the hammer falls with the bolt grossly open - say 1/4" or more, the hammer cannot strike the firing pin, but CAN contribute considerable power to drive the bolt closed.
3. That you have not stated the cartridge case ruptured in the open chamber indicates the cartridge was fully chambered when detonated...it cannot be otherwise.
4. Your position on the LEFT side was not suitable to view the ejection port...when your wife racked the operating knob the gun must have gone into battery, otherwise you'd have a blown case to show for it.
5. A .22LR that detonates outside of the walls of a supporting chamber virtually disintegrates.

On most if not all modern .22's out of battery fire is prevented by hammer-to-bolt angle interface. By positioning the hammer's axis of rotation well below the bottom plane of the bolt, IF the hammer is released during the bolt's travel it will simply "ride" the bolt home without enough free energy to cause the firing pin to detonate the priming compound. A good example of gun design before this understanding was incorporated in design is the 1911 pistol. The 1911's hammer pivot is very close to the slide's underside. This results in the hammer being held fully cocked until the slide is almost closed....which is why 1911's will "go full auto" everyday of the week if the disconnector is removed, but the GSG is NOT of such design. The GSG hammer pivot is WELL below the bolt line and if released by a pull of the trigger with the bolt "half-way open" or substantially less, will dissipate its energy on the bolt's lower radius leaving insufficient energy to depress the firing pin.

dizzny1 · « **Reply #63 on:** January 20, 2012, 11:55:52 AM »

Thank you for your insight, I believe that the hammer would exert the force needed to shove the bolt in such a way that the pin could hit. I had forgotten to mention that when the round went off, it was only halfway in the barrel. The rear of the shell desintegrated like you said, leaving the fron half of the shell inside the barrel right at the feed. I had to use a cleaning rod to push it out, and bore scoped the barrel and surprisingly it did not do any damage to the paper thin barrel. we got lucky, but now I have some ideas to prevent and a better understanding of what happened. Thanks for all your help

dizzny1 · « **Reply #64 on:** February 13, 2012, 12:51:31 AM »

By the way, a little off topic but I had a huge problem with my gsg receiver being a MAGNET for moisture. On a warm day when I was out shooting I had it in its case while i shot other guns, and when I went to grab it it looked like I dipped the gun in a bucket of water and threw it into its case. even on days when it wasnt so bad, if I did not clean it that same day I shot it white crap would form on the outside of the receiver and it looked terrible. I carried the old 522 cocking tube which was made out of the same zinc magnesium alloy as my receiver to my gunsmith and he put a coating over it and told me to test the hell out of it. when I got it back the coating actually worked to protect the metal and keep moisture from accumulating. The white stuff I told you about no longer showed up. With the test a success I sent him my receiver to be coated and we will be back in buisness

edgecrusher · « **Reply #65 on:** February 13, 2012, 05:49:20 PM »

wow, not sure how much changed between the 522 and the gsg5, but after about 1300 rds i no longer have any issues with my 1st gen gsg5. it eats all high velocity 22lr ammo, has no ftf or fte's, hopefully yours sorts itself out a bit for you. good luck, be safe

imschur · « **Reply #66 on:** February 13, 2012, 08:00:57 PM »

I dont think Kilibreaux will reply again. He changed his email to a fake one. By doing that he is unable to get the confirmation and wont be able to log in.

Kilibreaux if you read this contact me through the main site so we can straighten this out.

lmao_37 · « **Reply #67 on:** February 14, 2012, 12:11:11 AM »

I took my gsg AK47 apart and looked at the trigger assembly and it has the same hammer strut in it I have done the hammer strut mod to it just now waiting for some range time now to try it out I have also done the mod on the trigger over travel thanks kilibreaux

BulletCushion · « **Reply #68 on:** April 07, 2012, 03:17:42 PM »

Just bought the GSG 522 on tuesday and had my 1st chance to shoot it today. Had a great time. I did the hammer strut mod befor i ever put any rounds through it and it performed flawless. I tried 4 differents types of ammo: Federal Auto match, CCI MiniMag HP, CCI Stinger, and CCI AR Tactical. All were good but the CCI AR Tactical had the best groupings out of the bunch.