[peter2772000]

I recently picked up a brand new Gen I .40 AS, tried it out on the range last night. During the course of firing a ten round mag, the slide will fail to go fully forward at least twice. The slide will be held back about an 1/8". The kicker is that if I pull the trigger while the slide is in this position, the slide will fall back into place. Yet another pull will fire the chambered round. It'll do this approx twice in ten rounds.
Any ideas?

 

[Biscuit64]

I would give the gun a good cleaning and oil the gun alittle on the heavy side,maybe grease the slide.I like Tera Gun Grease .The gun might need a little more break-in time,250-500rns.I have bought new guns in the past that had weak recoil springs from the factory,a call to Wolff Spring for a new recoil spring cured the problem.For our p-99s the call would be to Walther for a new spring,the last time i checked Wolff didn't make any.Good Luck

 

[C45P312]

Let us know how it acts up after a good clean and lube.

 

[Parabellus]

if I pull the trigger while the slide is in this position, the slide will fall back into place.

I would never pull the trigger on a round not fully in battery.

Russell

 

[MGMike]

I would never pull the trigger on a round not fully in battery.

Russell

AMEN.

You did not say what kind of ammo you were using; if it was some kind of soft-point, see if the problem goes away with US-made FMJ ball. If not, the first thing to determine is whether the slide's failure to close is due to the cartridge hanging up partly into the chamber, or because of some mechanical interference involving the striker. If a light rap on the back of the slide will close it, it's probably the former; if not, then the latter--which is not something that can be diagnosed from afar.

M

 

[BreakerDave]

Also take a look at the mags... The first gen P99's in .40 S&W had a problem with the first gen mags interfering with the action cycling properly. If your mag has an orange or black follower, try the redesigned second generation mag with the blue follower and see if the problem repeats.

 

[peter2772000]

The pistol came with two blue-followered mags, but thanks for the heads up.
As far as not pulling the trigger in a slide that hasn't closed completely, I simply replicated what would woulda happened under a stress situation. I do understant the danger of what could have happened if the cartridge had fired with a partially open slide, though. But I was under the impression that the firing pin safety couldn't disengage from the pin (striker) unless the slide was pretty well closed. Which would explain why the gun didn't fire.
Matter of fact, I waited 20 seconds after pulling the trigger and watching the slide go the last 1/8" into battery. I then ejected the cartridge and there was no hit on the primer, not even a trace. Does that provide any clues to you guys? I'll be dissembling the gun tonight and inspecting it thoroughly.

 

[peter2772000]

AMEN.

You did not say what kind of ammo you were using; if it was some kind of soft-point, see if the problem goes away with US-made FMJ ball. If not, the first thing to determine is whether the slide's failure to close is due to the cartridge hanging up partly into the chamber, or because of some mechanical interference involving the striker. If a light rap on the back of the slide will close it, it's probably the former; if not, then the latter--which is not something that can be diagnosed from afar.

M

Sorry, don't have an edit button....yet

I was running hardball American Eagle 165 grain

 

[MGMike]

Is this the same gun on which you modified the striker?

M

 

[peter2772000]

Nope, that was a QA. By modifed, I mean sanded as per Turbo's instructions. Haven't changed the spring eyt. That QA, by the way, is now shootin' awesome (well, at least much better than before) since the mods as per Turbo.
Took the AS apart tonite, couldn't find anything blatantly wrong with it. Other than the fact it was dry as a bone, no lube whatsover. Oh, and the striker spring does the wavy wavy just like the QA. Mebbe the pic Turbo posted of his AS spring may have been from a Gen II???

 

[P99Freak]

Nope, that was a QA. By modifed, I mean sanded as per Turbo's instructions. Haven't changed the spring eyt. That QA, by the way, is now shootin' awesome (well, at least much better than before) since the mods as per Turbo.
Took the AS apart tonite, couldn't find anything blatantly wrong with it. Other than the fact it was dry as a bone, no lube whatsover. Oh, and the striker spring does the wavy wavy just like the QA. Mebbe the pic Turbo posted of his AS spring may have been from a Gen II???

Hello

this is a long shot, but, in my very naive opinion, you could strip it down and insert the recoil spring, without the slide and barrel in the metal hooded area where this spring is supposed to act inside the frame. Since you have both guns, make it with both. I think that the spring is too new and sometimes it gets entrangled in the hooded area, some coils at least. i would even add a bit of light grease, (oil will not help), but that should go away at 300 rounds, that is when Earl says the recoil spring will break in. In any case, since you are not assembling, it wont harm your lovely gun.
Congrats on having both.

Sorry if this does not help, i am not a smith, just a mechanic in a factory.

regards and good luck

 

[peter2772000]

Well, the AS was dry, so maybe lubing it'll help. But I sincerely doubt it. For the slide to come to within an 1/8" and having the trigger drop it back into place....I dunno.
Thanks for your input though. I'll let y'all know how it goes now that she's lubed up.

 

[peter2772000]

Update;

She's fine now. I spent a weekend dry-firing her (using a spent casing, is that Kosher?) and I could see the slide hang up about 3/8" of an inch before returning to battery. The extractor already had it's claw around the rim, so that wasn't holding it up. A 3-5 lbs push against the rear of the slide would send it back into battery. Regardless, I played with the action all weekend & brought her to the range last night. Flawless. Ran both CCI & American Eagle 180 grain with nary a hiccup.
Petey happy now!

 

[MGMike]

So why is (or was) it hanging up?

M

 

[peter2772000]

I believe the official medical term is Waltheritis. Lack of sufficient shooting with a genuinely awesome firearm....

 

[MGMike]

Perhaps a new strain of Herpes Umarex...

M

 

[peter2772000]

LOLOLOLOLOL

 

[MGMike]

In all seriousness --and I don't mean to belabor this-- if it were MY gun, and I had to manually push it shut to close it, I would want to KNOW what had been causing it. If I didn't find a badly fouled chamber or dirty or ill-fitting mags, it's a fair bet that something inside got worn off or mashed down or swaged through enough to allow the gun to function. I'd be tearing down the gun looking for bright spots, and hoping it wasn't something serious that might cause problems later.

M

 

[peter2772000]

Yeah, I hear ya. I initially though it was tight headspacing that was partially/completely to blame, because it did this only on a full round or spent case. But I determined that this was not the case. I think it was hanging up on the trigger mechanism itself, somehow.
All I know is, it's been functioning flawlessly since the dry-fire weekend. By the end of the day Sunday, I couldn't get the slide to hang up as it would normally do. I'm gonna tale all my guns apart for a good cleaning over the weekend, and then give the AS another workout next week.
I'll keep you informed, Mike