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Discussion Starter #1
I'm just starting to get my KP97D broken in. I'm up to 450 rounds and it functions great. Wednesday night I shot a 100 rounds of my reloads through it and I noticed toward the end that the trigger was getting harder to pull. I also noticed that the last little bit before the gun fired that the hammer was actually moving back a noticeable amount. Most of my P-Series triggers have become a little smoother as I shoot and dry-fire them more, but this one is getting progressively worse. Any ideas what might be causing this?
 

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rman, Yes, you have an under cut sear. This is very normal in all Ruger P-guns and most other brands of guns. To prevent pushoff and the posibility of a gun going full auto, the sear notch in the hammer is intentionally cut slightly under square (less than 90 deg engagement). If you place the empty gun on a bench and watch the hammer while pulling the trigger in SA mode, you can actually see the hammer move back slightly before the sear releases and the hammer drops.

Personally, I think you are flirting with danger if you try to "fix" it. On a new gun, this is hardly noticable because the part's mating surfaces are a bit rough and hide it. After the gun begins to break in, you can feel things that you could not feel before, even though it was there all the time. It won't get any worse but you might be able to feel it more as the gun continues to break in.

Look at my post in this thread. Though this is a SA revolver, the mechanical sear concept is the same in a P-gun. The difference is a SA revolver won't go full auto! http://rugerforum.net/topic.asp?TOPIC_ID=131&whichpage=2
 

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Discussion Starter #3
It's a little disconcerting, but I can live with it I guess. I'm not skilled enough to start honing on the sear. Thanks for the info!
Tom
 

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Discussion Starter #4
It's getting worse. When I'm dry firing I can hear a noticeable, kind of scraping sound and then a clunk just before the trigger breaks. This can't be normal - none of my other P-Series do this. I did a thorough cleaning and lube, but it makes no difference.
 

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rman, It's hard to say for sure without having the gun in my hand, but the grating sound/feel may be coming from something other than the sear itself. As you pull the trigger, the trigger bar moves forward and several things happen.

In DA mode, the trigger bar pulls the hammer back. A rough hammer strut rubbing on the hammer spring will cause a grating feel. The contact surface from the trigger bar and hammer may be rough.

In both SA and DA, the first event is where an extension of the trigger bar pulls the blocker lever which in turn pushes the firing pin block plunger up. This is a safety device that prevents the firing pin from going forward until the trigger is pulled. The plunger is located in the slide and can be seen from the bottom of the slide, directly under the rear sight.

In SA mode, the second event is when the trigger bar pulls the sear forward until the hammer drops.

Your grating noise/feel can be coming from either event. You can trouble shoot it by removing the slide and dry firing in both SA and DA modes. You need to flip the ejector plate back, hold downward pressure on the firing pin block, then cushion the hammer blow so it doesn't damage the frame or hammer. I use an old rag draped over the cocked hammer.

With the slide off, if your grating is coming from the trigger bar, blocker lever, or sear, you will still hear/feel it. If the trigger pull is good, the grating is coming from the firing pin block plunger. You can use a tool to press the plunger up manually. It should move nice and smooth.

Here's some pretty normal things that can cause your grating. The sear may be rough. Look for machine marks or wear on the sear contact surface. The sear notch in the hammer may have machine marks or wear spots. Dress the sharp edges on the hammer strut, DA trigger bar, and hammer surface.

The trigger bar is a stamped part and always has very sharp edges that can bite in to a mating part instead of moving smoothly. It has three extensions, one for the sear, one for DA cocking, and the other for the block lever. A rough mating surface on the trigger bar's extensions or the other half of the mating surfaces on the sear or blocker lever can easily cause grating. Also, the trigger bar can grate on the frame.

Here's what I would do. With the slide off, operate the trigger so you can see each mating surface. Do a total tear down on the lower frame, then use a jeweler's file to dress all the sharp edges from the trigger bar. Locate the mating surfaces and clean them up, first with a fine file, then buff the surface with a buffing wheel. Do the same for the sear and blocker lever.

Remove the rear sight and take the firing pin blocker out. Dress the mating surfaces, clean out any crud or machine marks on the blocker and the hole for the blocker.

By doing the above, likely you will find the culprit. After you get the gun back together, you will notice both SA and DA trigger pull will feel way smoother. It also makes the gun last longer because when smooth surfaces rub together, wear will be minimal.

OK, the last issue is dry firing. When I owned my gunsmith shop, at least 25% of the repairs were because of excessive dry firing (a good source of revenue for me). I see a lot of "dry fire to break in" suggestions on all the forums. This is probably the worst advise given and comes from people with no gunsmith experience. Think about this: if you have a smooth part mating with a rough part, soon you will have two rough parts. Continued dry fire will eventually wear both parts. Yes, the action will be smoother, but at the expense of damaged parts. Imagine this: take a nice smooth board and sand it with 60 grit sandpaper. After just a few strokes, the board will have deep scratches from the sandpaper. If you sand it long enough, eventually the sand paper will wear and both the board and sandpaper will become smooth. By this time, the board has worn thinner and the sandpaper is worn out. The same concept applies to guns.

If you have two smooth parts rubbing together, both end up getting polished with use and become even smoother. If you tear down a new gun and smooth all mating surfaces, dry fire won't hurt a thing. I also see a lot of suggestions about using "snap caps". They are great but they only protect one part; the firing pin. All the other parts of the gun still wear. I think this is a false sense of security.

Rant off.
 

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Discussion Starter #6
Thanks for the great, detailed advice. I'll try some of your suggestions and see if I can determine where the problem is coming from. Your 'rant' about dry firing makes perfect sense. I don't usually do much of it, but when you're firing live ammo with ear protection, you can't tell as much about what is going on. I was really surprised to hear that bad things were happening when I pulled the trigger. I don't expect Rugers to have a match trigger, but this one is really bad and getting worse. Thanks again, Tom
 

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rman, This is by no means a slam on Rugers because it happens in every production gun on the market. That said, Rugers (especially P-guns) are "assembled", not "hand fitted". Hand fitting would increase the cost of a gun by a huge amount. Ruger parts are not "dressed" at the factory. Nearly all parts are either stamped on a punch press or cast. Either way, they tend to have rough or sharp edges on mating surfaces.

Most people think an "action job" is strictly for trigger pull. No doubt, it will improve trigger pull a lot but it also makes the parts work better together, thus reducing wear and giving the gun a better overall "smooth feel".

I highly recommend doing an action job on every gun you buy. If you can't do it yourself, a competent gunsmith can do it for a reasonable fee. With guns, often two or three things can contribute to that raspy feeling. For that reason, I don't even bother trying to trouble shoot a gun with friction issues, rather I tear them down and dress all parts. It can make a night and day difference!
 

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quote:Originally posted by rman

I'm just starting to get my KP97D broken in. I'm up to 450 rounds and it functions great. Wednesday night I shot a 100 rounds of my reloads through it and I noticed toward the end that the trigger was getting harder to pull. I also noticed that the last little bit before the gun fired that the hammer was actually moving back a noticeable amount. Most of my P-Series triggers have become a little smoother as I shoot and dry-fire them more, but this one is getting progressively worse. Any ideas what might be causing this?
rman, Iowegan is right on the "money" once again! I have performed action jobs on everything I have owned for many years now and highly recommend it for everyone! Not so much for the enhanced "trigger" pull, although that is an added benefit, but to have all parts moving as "friction free" as possible. What a pleasure it is to fire those guns! The "only" guns I don't recommend an action job on are something like the old Webley MK VI I own. That old "bucket of bolts" is as loose as "rocks in a can"! It shoots fine and I love that old piece just the way it is. It was given to me. I could "tighten" it up a bit but I like the "originality" of that old piece and as long as it is "safe" to shoot, it will remain as such while I own it!......................Dick
 

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Discussion Starter #13
I assessed my gunsmithing skills (not!) and decided to ship it back to Ruger. Tracking says they got it on the 23rd of March. I received a note from them yesterday acknowledging receipt. I suppose it will be a few weeks before I get it back. I'm getting axious - I really like this gun. It's pretty accurate and will just plain shoot anything I feed it.
 

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Have you received this firearm back from Ruger yet? I am looking forward to how your experience with Ruger went, and how it shoots when it comes back.

Thanks!

Jay1958

quote:Originally posted by rman

I assessed my gunsmithing skills (not!) and decided to ship it back to Ruger. Tracking says they got it on the 23rd of March. I received a note from them yesterday acknowledging receipt. I suppose it will be a few weeks before I get it back. I'm getting axious - I really like this gun. It's pretty accurate and will just plain shoot anything I feed it.
 

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rman,
I am also curious also about how you made out with customer service. Looking forward to your update.
 

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Yep haven't been here that long and have learned a lot, nice place
 
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