Accidental discharge when decocking?

[M1A]

I am relatively new to the forum and to HK's in general. (I have owned other guns for many years but recently purchased my first HK). I have read two threads that mention an accidental disharge when decocking. I believe one was a P7 and one was a P9. Is there some type of design flaw that allows this to happen on these older guns? If so, has this been corrected on the newer guns? I know we don't always get the full story from a thread. Maybe those guns had huge round counts through them or had been abused. It is still a bit disconcerting for someone new to the brand.

[AviatorDave]

I am relatively new to the forum and to HK's in general. (I have owned other guns for many years but recently purchased my first HK). I have read two threads that mention an accidental disharge when decocking. I believe one was a P7 and one was a P9. Is there some type of design flaw that allows this to happen on these older guns? If so, has this been corrected on the newer guns? I know we don't always get the full story from a thread. Maybe those guns had huge round counts through them or had been abused. It is still a bit disconcerting for someone new to the brand.

Definitely not a P7 - they don't have a decocker. To cock the striker, you squeeze the cocking lever at the front of the grip. When it's released, it can't fire.

You may have read something about the USPs and that when they are decocked, they are not also placed on safe at the same time. They are just decocked, but the hammer can be recocked and fired by a pull of the trigger. To put them on safe requires moving the lever so "S".

[Big Bore]

Decocking a USP/C cannot fire the pistol if you do it the way you are supposed to, using the decocker. The firing pin block prevents the pistol from firing as well as the half-cock (decock position) notch. The ONLY way it can fire is if you decock with your thumb while pulling the trigger and your thumb slips. Then that is not an AD but an ND.
Ditto the P7.
Not sure about the P9 because I have not shot mine and it has been years since I have shot one and right now I do not recall the internals that would prevent a discharge when decocking, but again I'd wager it would be operator error such as decocking with the finger on the trigger.

[Lukas Koukal]

It MAY happen with the P9S, as You have to pull the trigger to decock it. If Your thumb slips from the cocking lever in that very moment, it will go off. I can´t think of anything else but operator´s error with these guns.

[Gunner777]

I've never heard of this happening and frankly from the pistols design I believe it's impossible unless the user has his or her finger on the trigger at the same time and induces a user AD.

[dc42nr86]

Maybe an older model USP which doesn't go back to the half-cock position?

[uspswatcop]

It's not impossible. It happened to one of my team mates a few years ago and after it went off he swore to holy hannah that he did not have his finger on the trigger.

Our team armour took that earlier model USP .45 and set it up (with a video) and he was able to get the gun to do the same thing while decocking following normal procedure.....ie no finger on the trigger etc.

It did happen and the video and the gun went to HK. The gun was fixed by HK and went back into service.

If anyone doesnt believe it can happen I can put you in contact with our team armour but keep in mind don't call him because you are a fan of the usp and want to shoot the **** with him. If you have a legimate reason I will put you in contact with him for the details.

Mikey

[F22_RaptoR]

It's not impossible. It happened to one of my team mates a few years ago and after it went off he swore to holy hannah that he did not have his finger on the trigger.

Our team armour took that earlier model USP .45 and set it up (with a video) and he was able to get the gun to do the same thing while decocking following normal procedure.....ie no finger on the trigger etc.

It did happen and the video and the gun went to HK. The gun was fixed by HK and went back into service.

If anyone doesnt believe it can happen I can put you in contact with our team armour but keep in mind don't call him because you are a fan of the usp and want to shoot the **** with him. If you have a legimate reason I will put you in contact with him for the details.

Mikey

It may have had a faulty/damaged firing pin block.

The older USP's didn't have the "half cock notch" but they still have the firing pin block.

[cueist]

Lukas is right about the P9S since you have to push the release-lever down then pull the trigger in then release the release-lever then let the trigger out. It is easy to make a mistake if you try to decock the P9S too fast.

F22 is correct in that the older USP's (both Full Frame and Compact) didn't have the half-cock notch and that the block could have been damaged.

[Tabsr]

I have an older USPC bought when it first came out. Aprreciate knowing the year cut off for the half decock.

[cueist]

When you decock your USPC the hammer will either go all of the way down to the same possition as when fired or it will stop in a halfcock possition which is 2/3's of the way before fired possition.

[Gunner777]

I've just never had a problem like that. Mine is a 1998 and has the half cock function.

[Tabsr]

Mine is code KH, 1997 and looks like a partial hammer decock.

[ydaho]

my usp 45 is a KE (1995) and it doesn't have the half cock portrusion notch like the later model usp's have. It has done fine.

[mkivbb]

wow, this is scary. i've never heard of that happening, but the way a usp de-cocks, is still kinda scary to me every time i do it with a round in the chamber.

[ydaho]

You should always decock in a safe direction (away from self and people). However, mistrusting a guns safety devices is unsafe in my opinion. In other words, acting scared around guns is not safe, nor is being cavalier around guns either. Confidence in safety and gun nomenclature is the safest route. I trust my decockers on all of my different models; hk, beretta, baby eagle... I think hk's are very safe guns, especially because you can manipulate the slide with the safety on. I think the hk decocker is just fine.

The beretta 92 decocker rotates the firing pin actuater out of alignment with the rest of the firing pin and the hammer falls all the way down. I think the system is just as safe as the hk usp's.

Iv'e never mistrusted a decocker. I think it is bad karma to do so. Whatever.

[SlayerGGX]

The USP (particularly the newer ones with the half-cock) is remarkably safe when it comes to decocks.

I did have this happen to me with a PPK...scared the bejesus out of me. Will never fire that gun again.

It IS possible, just not very likely on the USP.

[F22_RaptoR]

If you want to be EXTRA sure, just use the decocker, and then let the hammer down with your weak hand, like you would with a 1911 (except without pulling the trigger).

I use my Mark23's decocker this way, but i do pamper it :p

[RX7-2nr]

take the slide off a USP and watch the hammer area while you pull the trigger. the hammer block only falls out of the way once the trigger is pulled quite a way back.

[F22_RaptoR]

take the slide off a USP and watch the hammer area while you pull the trigger. the hammer block only falls out of the way once the trigger is pulled quite a way back.

Yep, its called the "Sear Actuator" its the part that the trigger bar "touches" in SA mode, or at least thats the way my Mark23 is.

[snitchy]

[QUOTE=AviatorDave;552075]Definitely not a P7 - they don't have a decocker. To cock the striker, you squeeze the cocking lever at the front of the grip. When it's released, it can't fire.


Oh yes a P7 can fire while de-cocking! My M13 began to fire when I released the de-cocker. After the first time this occured, I could fire the pistol by just releasing the de-cocker, never touching the trigger. HK fixed it for free. Since I got it back, I only chamber the first round by physically releasing the slide. I am in no way saying anything negative about the gun. Just a weak part in an older model that needed to be replaced. It will not happen with the newer part! My P7M13 is what I want in my pants when I don't have the luxury of a sniper rifle!

Remember, treat everyone with respect, but be prepared to kill them!

[F22_RaptoR]

[QUOTE=AviatorDave;552075]Definitely not a P7 - they don't have a decocker. To cock the striker, you squeeze the cocking lever at the front of the grip. When it's released, it can't fire.


Oh yes a P7 can fire while de-cocking! My M13 began to fire when I released the de-cocker. After the first time this occured, I could fire the pistol by just releasing the de-cocker, never touching the trigger. HK fixed it for free. Since I got it back, I only chamber the first round by physically releasing the slide. I am in no way saying anything negative about the gun. Just a weak part in an older model that needed to be replaced. It will not happen with the newer part! My P7M13 is what I want in my pants when I don't have the luxury of a sniper rifle!

Remember, treat everyone with respect, but be prepared to kill them!


ANY gun can "fire" if damaged or malfunctioning ;)

Its just easier for some than others. With the USP you need to defeat the half-cock notch AND the firing pin safety for it to "AD".

[G3Kurz]

[QUOTE=AviatorDave;552075]Definitely not a P7 - they don't have a decocker. To cock the striker, you squeeze the cocking lever at the front of the grip. When it's released, it can't fire.


Oh yes a P7 can fire while de-cocking! My M13 began to fire when I released the de-cocker. After the first time this occured, I could fire the pistol by just releasing the de-cocker, never touching the trigger. HK fixed it for free. Since I got it back, I only chamber the first round by physically releasing the slide. I am in no way saying anything negative about the gun. Just a weak part in an older model that needed to be replaced. It will not happen with the newer part! My P7M13 is what I want in my pants when I don't have the luxury of a sniper rifle!

Remember, treat everyone with respect, but be prepared to kill them!

P7 Drop Safety Package

P7 Drop Safety Package

Noting is impossible in mechanical devices. Man is not perfect and neither are those things he creates. That is why is it always important to keep them pointed in a safe direction at all times. I have seen many other handguns go fully auto or fire when “decocked”. Ever watch a 1911 go fully auto because of a bad trigger job? If one is not prepared the 7 rounds will be gone in under 2 seconds and could head in an unsafe direction. For that reason those who shoot customized 1911’s in 3-gun shooting usually loaded with their finger between the hammer and slide just in case. Now to the P7.

If you read carefully the current P7M8/M13 op manual you will see the caution about cleaning around the firing pin block (FPB) in the slide. Toothbrush bristles can accidentally release one end of the FPB spring. The FPB may then fall out of the slide sometimes w/o you knowing it. Now the only thing that prevents the firing pin from moving forward to strike the primer is the sear lever. If you have old-style parts (sear lever w/o a upward angle at the rear end and 5-7 other parts that go along with it depending on P7 model and date assembled - incorporated into P7's in the late 1980's) and the sear lever/firing pin interface surfaces are worn (beveled from use, or modification to "improve" the trigger pull - NEVER do this!) it is possible that this could occur, the "wing" on the firing pin overriding the sear lever and then fully free to project from the face of the slide. SO ALWAYS CHECK during reassembly that your FPB is in place and the two spring arms are engaged and that there is spring tension in the FPB (do not pull hard on it or it will come out!). Do not use force with a brush in the rear area of the slide where the FBP resides. If you do not have new style parts in your P7 send it to HK for the upgrade. If your FPB is missing, do not use the pistol until a new one is correctly installed. This all was learned when the HK engineers said in the 1980's "dat ist impossible" in response to a German police report that a loaded P7 (PSP) fired when accidentally dropped in a stairwell. After some close examination and MANY TEST DROPS it was proven to be possible though highly unlikely and ALL German P7’s were retrofitted. That is when the new "drop safety parts" were created and were incorporated into all new P7 production and replaced in departmental guns in the US, and on civilian repairs when sent in for that issue or something else. The P7 like many firearms are marvelously safe but like anything man made they will "bite you" if you do not respect them. Old and new style P7 drop safety parts are not compatible with one another and there are additional parts needed for the P7 (PSP versus the M8/M13). The only way to know for sure is for a fully qualified HK armorer to inspect them.