Received Mr. Gray's replacement trigger. Hot dog.
In the quiet of the morning I started the replacement in P320C9 with the instruction video next to me. Task starts about 6 minutes into the video. Needed to use the edge of narrow punch to un-hook spring where it is attached to the frame.

Then I proceeded to replacing 2.5mm pin. Have a block with holes and grooves that looks almost like one in video, but no position was free of interference. That is to say, the thing has so many protrusions that finding a place where a hole appears under the pin-to-be-removed AND does not involve pressure on things that probably should not be pressed could not occur. Stupidly, I found a spot that seemed not too bad and used 3/32 punch to start pin. Then, as suggested, I started the new pin. Had to hit hard. . . and then the sky fell in!

One of the very small springs fell out. So now I have to rebuild the thing in order to return the little spring to where it goes. Not happy.

If you can not craft a block that holds everything in place except for the pin, do not even try to replace the pin. Too much can go wrong. Mac

I feel your pain. The same thing happened to me. The safety lever pin is a fairly loose fit and, since it requires some good whacks to get the new sear housing pin in, it can bounce out a little bit during the process.

If the safety lever spring fell out (pretty likely) the good news is that you don't even have to remove the sear housing from the frame. I was able to get it back together by backing out the safety lever pin very slightly and carefully inserting the safety spring. I held it in place with a screwdriver and pressed the safety lever pin fully in to hold it.

The great news is that the Gray Guns trigger is excellent. The reduction in trigger pull is nice but the flatter face of the curved trigger is perfect for my finger placement. I was having some issues shooting slightly left at longer ranges. Those are gone with the new trigger. I'll be ordering them for all of my 320's as soon as more are available.

Great to hear that . You like the curve better than the straight? Does anyone have both to report what they like about each?

Well, ok, so I'll start working on an armorer's block later today.

I personally prefer the straight but I went with the curved as this was installed on my Production back up gun.

I've always liked flat triggers so I bought the Apex when it came out and it's very good. However, I prefer the Gray Guns curved over the Apex by a wide margin. I bet that the GG flat would be just about perfect for me.

An armorer's block would be great! I'd be the first in line.

With the benefit of your comments and experience + my experience: One needs to wrap the whole assembly tightly and then secure with tape or rubber-bands with the aim of preventing any of the stuff backing out or becoming displalced while banging on the 2.5mm pin. AND one needs to find a piece of solid plastic or flat wood that can receive just the end containing the pin, note where the pin touches the block, and drill a 3 or 4 mm hole in the right place. In other words, a tailor-made block is desirable including confining anything that can get loose.

Have a conventional block (looks like what Mr. Gray uses) and a wonderful block made by Apex that works with M&P, Glock, and can be adjusted to several other pistols. P320 is different!

I continue to be astonished that P320 will become M17 because of its many small parts. However, the silver lining is that at last descriptive manuals will be available.

I see where one can -as suggested - back out the plastic pin than must have held the now liberated spring and, with luck, capture the little spring. However it is not clear how the ends of the spring should be (could be) secured. In other words, it must be more than just having the spring between the part that looks like a sear and the frame (captured by black plastic pin). The thing that looks like a sear is now loose and clearly missing a spring. Mac

Is it possible to send the FCU to Mr Gray for PELT installation? I suppose that would be cost prohibitive, with shipping equal to the cost of the PELT.

Mac. I sent you an email with some more details. Hope it helps.

As was noted: The spring that fell out is "safety lever spring." It is captive between the "sear housing assembly" and the "safety lever." The actual "sear" is next in line. All kept in place when in the frame by "safety lever pivot pin" inserted through the left side of frame.

The "safety lever spring" legs should point forward with the lower, outside leg resting against a lower recess in the "safety lever." It might be that the "safety lever spring" is capable of being inserted backwards.

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Because of the edge bevel of conventional block and because it is circular, it is not clear if I can drill a new hole (near an edge) to deal with the pin. But I will test the next time.

Still, suggest that means for securing all of the other pins and protrusions needs to be effected before hitting on the 2.5mm pin.
Mac

quote:

Originally posted by 4MUL8R:
Is it possible to send the FCU to Mr Gray for PELT installation? I suppose that would be cost prohibitive, with shipping equal to the cost of the PELT.

Of course you can. However, you are looking at shipping a handgun both ways expense wise. If you have a SIG gunshop nearby, however, their armorers/gunsmiths may be able to do it much cheaper. As always, if you are in my neighborhood, I'd gladly throw it in for you for free.

Regarding replacement of the 2.5 mm sear housing pin. Bruce states that it is optional. It only HAS to be used if the sear housing/chassis interface has movement. Movement can create issues with the reset function.

I did not bother replacing the pin on my Jan 2015 P320C 9 mm. There was NO movement between the sear housing and chassis. Felt like it could have been welded in (joke). If the housing eventually begins to develop play, I'll put the GGI replacement in then. You can pull out your own FCU and check in advance to see if you will need to replace it. That only leaves the trigger and TBS to install.

Only thing I installed was the trigger itself. Used the Sig factory TBS, since it is a carry gun. Went from 8 lb to 5 lb 4 oz. Used a quality Timmney triggger pull scale (spring, not electronic). The measurement was taken several times and was repeatable. Used method Bruce shows in the video.

More important than weight is the overall feel of the trigger itself. VERY clean and smooth trigger travel. Even though my P320 had a stellar trigger (carry), the GrayGuns replacement made it even better. Again, because of the trigger personality as opposed to weight.

I'd describe the trigger as not feeling like a striker fired pistol trigger. Still has a slight amount of travel, but that's it. I'd compare it more to the SA on my classic DA/SA Sigs. Not exactly, but pretty damn close.

I'll be posting details on my install and results at a later date. Great job Bruce.

EDITS: Just clarifying some of the points.

This message has been edited. Last edited by: Nipper,

A slightly off topic suggestion for those of you who do not have a bench block:

Buy a couple HOCKEY PUCKS. Relatively cheap, durable, and easy to customize with holes and grooves using just a drill or a file.

Hockey Puck is a good idea.

Progress (well, sort of) report:
Managed with effort to replace trigger and trigger spring with Mr. Gray's parts in a P320F9 last night. This pistol has had several hundred rounds through it. Required force went from 6 1/2 pounds-force to 5 1/4 pounds-force with a long creep. Found it difficult to attach new trigger spring - must be missing a technique.

This morning I tried to replace trigger and trigger spring in an early P320C9. Great difficulty attaching trigger spring and then found that pistol would only fire once in a while. Apparently, the useless magazine safety is not working correctly and preventing trigger's connection to sear. Quite a lot of parts are involved with that "safety." Could be dirt or that the new trigger adversely impacts linkages involved. Another work-in-progress.

Will play this on the gunsmith list looking for ideas. Mac

quote:

Originally posted by P320Mac:
Hockey Puck is a good idea.

Progress (well, sort of) report:
Managed with effort to replace trigger and trigger spring with Mr. Gray's parts in a P320F9 last night. This pistol has had several hundred rounds through it. Required force went from 6 1/2 pounds-force to 5 1/4 pounds-force with a long creep. Found it difficult to attach new trigger spring - must be missing a technique.

This morning I tried to replace trigger and trigger spring in an early P320C9. Great difficulty attaching trigger spring and then found that pistol would only fire once in a while. Apparently, the useless magazine safety is not working correctly and preventing trigger's connection to sear. Quite a lot of parts are involved with that "safety." Could be dirt or that the new trigger adversely impacts linkages involved. Another work-in-progress.

Will play this on the gunsmith list looking for ideas. Mac

Call Grayguns. They will help you out.

quote:

If the safety lever spring fell out (pretty likely)

They changed the design to help prevent that.

P320Mac, I received my GrayGuns flat face trigger replacement kit Saturday. With enthusiasm, I proceeded to the task on my p320C. As I was hammering in the 2.5mm pin, 2 twin tinsy springs popped and a V shaped spring followed. I panicked! After a while I looked onto Youtube where I found a saving video from one Alma Cole who walked me through a complete disassembly and then reassembly of the FCU. Now, my FCU is functioning with a great trigger in place. I am happy now. And suggest it to everyone who wants to tweek the p320 FCU.

Thanks. I will look for the YouTube video.

One installation seems to have sort-of worked. One resulted in the loss of a little spring that I think I can put back in place. And one resulted in the magazine safety locking the sear.

However, several people have had a desirable outcome. . . . and I may too once the issues are dealt with. Mac

Yeah, once you get your P320 back into action, you'll be pleasantly surprised.

As I mentioned somewhere else, the GGI trigger felt more like the SA on a DA/SA Sig than a striker fired pistol. It's not the trigger weight, it's the geometry of the trigger design.

My P320 is a defensive pistol and it meets the same draw/fire accuracy standards as my other defensive guns. Sunday, after the GGI trigger install, I decided to do just a little seven yard slow fire for sh-ts and giggles. One or two handed, each three shot group were cloverleafs. The consistency of the trigger is amazing.

Thanks for the encouragement Nipper. The fat-lady has yet to sing. Sometimes, if it were not for bad luck one would have no luck at all.

Here is what I posted on Gunsmith page:
New information from morning labors: It became apparent that the magazine safety parts were not playing nicely. The "Takedown safety lever" (extends the whole length of the left side of frame) was not cooperating with the hole in "slide catch lever." Polished the sliding parts and lubricated same. Slid the parts back and forth many times. Reassembled and still the sear would be engaged only once in a while.

Compared the frame contents with the frame of another P320C without seeing anything different other than the other frames's magazine safety parts moved more freely.

Then I swapped slides. All of a sudden both P320C9 pistols worked! Present theory is that once the magazine safety parts started to cooperate, the "safety Lever" would only occasionally depress the "safety lock" (in the slide, series 80 task) sufficiently to be able to release the striker. Oh my. Bad pistol to be so temperamental. Ran out of time and still do not know if the new trigger is connected to difficulty. Even when fixed, pistol probably should be scraped. Sometimes-go-bang is just not OK.

I do note that the "safety lock spring" is relatively stiff.

Any ideas? Mac

I installed mine,today. The safety lever spring fell out. I call Gray Guns and they talked me off the ledge. A YT video and 30 minutes of cursing later, I have a working firearm with a much, much improved trigger.
The "soft reset" is disturbing to someone with many thousands of repetitions with a Glock trigger but I think I will get used to it. I think it may help me break my habit of trapping the trigger and not resetting under recoil

Bruce