I just wanted to give a very enthusiastic two thumbs up to Apex Tactical for their excellent customer service. Too many times we hear of companies that fall short, but in this case Apex went far beyond what they needed to do.
I contacted Apex about a Duty/Carry trigger kit that I had installed in my Shield. The installation went without a hitch, but a lot of different reasons prevented me from firing the gun for several months. I thoroughly cleaned the Shield after the install and it remained stored for quite some time. On the first trip to the range I experienced a no primer strike on every other cartridge. It would fire one and then the very next one would not fire or show any primer strike at all. If I ejected the cartridge and loaded a second one, it would fire. That ended that session and I took the Shield home, disassembled it and thoroughly cleaned it.
The second outing was better, but I still had that same no fire problem about 25% of the time. Again I took the Shield apart, recleaned it and inspected it for any obvious problems. I couldn't find any. If I dry fired it, I could not duplicate the problem and to test the firing pin operation I used a BIC pen in the barrel. It never failed to launch the pen 10-12 feet so the source of the problem still remained a mystery.
For some strange reason on the third trip to the range, the gun fired perfectly, and on a fourth trip it also ran fine. But getting back to Apex. After the first trip and the disappointing failure, I contacted Apex just to see if they had any idea if it could be related to their product. After discussing all sorts of ideas such as type and brand of ammo, where I purchased the Apex kit, how many rounds were fired from the Shield before and after the installation of their kit, and whether I had adjusted the trigger loop bar, nothing definite stood out. Apex requested and I sent them detailed pictures of the Shield just to verify that everything was installed properly. Evidently it was, but from the pictures they could tell that the kit that I installed was one of their earlier kits.
Apex is continuously improving their products and they told me that they had a kit with a new and improved sear and a new ultimate striker block. The next thing I knew Apex told me that they would send me a new complete kit to me to install to see if it helped the problem. They asked for me to return the old kit in a prepaid envelope to them for evaluation. I was blown away. There really was no solid indication that the problem was even the result of the Apex kit installation.
Fast forward a couple of days, the kit arrived and was installed. Installation went very well and the trigger does have a little crisper feel. I haven't shot the gun yet, but I'm optimistic that it will perform well.
As far as what caused the original problem, I still don't know. I have one theory, however unproven. I have always used Froglube and have been very happy with it so far. Just recently I got my Springfield TRP 1911 out to fire it after it had been setting for several months. I had also used Froglube on it. When I got it out of the safe and tried to rack the slide, I could just barely move the slide and when I finally released it it was very slow to return. Not good. It was fine when put away and it only has very few rounds through it. Out of curiosity I took a hair dryer and heated the gun up with it for a couple of minutes to liquify the Froglube and then retested the slide. It was much easier to rack and operated much slicker. After cooling off for a while, the gun reverted to it's old slow self confirming my suspicion that the Froglube had solidified and was gumming things up. The next day I disassembled the TRP, thoroughly cleaned it and lubed it with Mil-comm products. It runs as slick as whale snot now. I hate to knock Froglube, but I can't deny that it does seem to gum up the works if left on a gun for some length of time. When I regularly fire a gun I don't seem to have that problem and it does an excellent job protecting against rust and moisture.
Now back to the Shield. When I was installing the new kit, I noticed that the Froglube had migrated to a lot of areas that I had never intentionally applied it. In some cases it had formed a semi-hard sort of sticky jell. I know that this is supposed to liquefy when the gun heats up from firing, but I'm wondering if this sort of gummed something up to where it caused it to malfunction. Maybe my cleanings between trips to the range helped clear this up, or maybe it just cleared up on it's own from firing it. I guess I'll never know and I can't fairly put any blame on Froglube.
As a result of my findings I thoroughly cleaned the gun, AGAIN, and switched to Mil-comm products. I have yet to fire the gun, but so far it operates as slick as can be. So far it seems like all I'm doing is knocking Froglube and praising Mil-comm. That was not my intention, but if this information helps anyone, that would be great.
But back to the original purpose of my post. I just wanted to give Apex Tactical two big thumbs up for stepping up to the plate and supplying a new kit to me free of charge, even though there was no definite proof that their product was at fault. It shows me that Apex will go to whatever extremes to stand behind their products. I would recommend Apex to anyone.

Great to hear that Apex stepped up to the plate for you even when they didn't have to. I have their products as well. Top notch.
Did you clean out your striker channel and take apart your striker assembly and clean that as well? That area and striker needs to be bone dry.
I have heard that about froglube and storage. I will not use the product. I won't use rem oil either. Other than those two things most all the oils are excellent. I have gunbutter, slide glide, FP-10, Slip2000 EWL lube and grease and TW 25B grease. Along with a couple of others such as Ballistol, eezox, hornady one shot etc. They all work well.

Wow, rbuzz, that's a big ol' wad of words. Bet there's something interesting in there, somewhere.

In my experience, if you had enough FrogLube to gum up the works, you used too much.

Paragraphs are your friend.

You might be right there. What I used to do was to heat up the parts with a heat gun and then apply a liberal amount of either the paste or liquid. Then after letting them set for a while I would completely wipe the parts off with a micro fiber towel, removing all of the excess. Then upon assembly I would take a 3/16" artist brush and apply a thin coating to a few high wear areas.
It's possible that I did use too much, but in the case of the Springfield I didn't see any pooling, but the Froglube still solidified to the point that I almost couldn't rack the slide. I guess it's possible that in that type of metal gun there are closer tolerances and much more contact area, especially in the slide, than polymer pistols like the Shield.

Rbuzz,
You described the same problem I had after I had an apex trigger installed. After some trial and error, my gunsmith determined the trigger was not compatible with the magazine safety. We traded out the sear block and havent had a problem since then.

You had me at Two thumbs up for Apex Tactical...

I'm glad to hear that you fixed your problem. In my case I never replaced the actual trigger, I installed the Duty/Carry kit which includes the striker block and spring, and sear and trigger spring. I kept the stock trigger. My comments about Apex Tactical still apply. They have been great in helping me and went way beyond what they had to do to help.
After a very thorough cleaning and lubing with mil-comm products my Shield is operating well. I stopped using Froglube. I'm not saying that it was the cause of the problem, but I just couldn't accept the way it solidified on my Springfield TRP.
From my experience Froglube has worked very well on guns that are shot on a somewhat regular basis, but in the case of my TRP which set for a few months after cleaning with Froglube, it was for all intents practically locked up. I almost couldn't rack the slide. As a test, I took a hair dryer and heated it up and it loosened up to almost normal, but after cooling down it went back to where it was almost impossible to rack the slide.
After disassembling and thoroughly cleaning it, I lubed it with mil-comm and it's back to it's regular slick operation.
I've always been a big supporter of Froglube, but can no longer recommend it. I might use it as a protector for the finish on the outside, but for lubricating the internal parts I'll probably stick with mil-comm.

I have Apex triggers, sears, extractors, etc., in all my M&P's, Shields, and Glocks. Apex people are very dedicated and customer oriented.

Why do people keep using Frog Lube? I have tried just about everything and now exclusively use Slip 2000.

Apex is a great outfit. I have lots of their kit in my guns and my toolbox...

[QUOTE=
Why do people keep using Frog Lube? I have tried just about everything and now exclusively use Slip 2000.[/QUOTE]

I mainly started using Froglube because I heard so many positive reviews of it. I liked the idea that it had no harsh solvents in it and still protected the firearm from moisture. It did a great job cleaning the gun and generally you could almost get away with just wiping it off after it fired as most crud didn't stick.
Another of the main reasons was because my Arsenal SAM7 AK-47 has a finish that harsh solvents will damage. Froglube doesn't.
Like I mentioned before, in any firearm that I have that is shot fairly regularly, Froglube has worked great. But what recently caused me to have second thoughts is how it gummed up my Springfield TRP after it was cleaned with Froglube and then stored in my safe and not shot for several months. The Froglube solidified and I almost could not rack back the slide it was so bound up.
After that experience I decided to use something else and finally decided on mil-comm products.

Rbuzz,
My bust. I thought it was a trigger upgrade you were discussing. What upgrade to the M&P does the duty/carry kit give you?

I've said it before and I'll say it again. Frog Lube is best used for lubing frogs.

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NRA Benefactor

From the Apex sight:

The Apex Duty/Carry Kit for the M&P Shield was designed to provide the Shield pistol owner a smooth, consistent trigger pull that is approximately 2 lbs lighter (based on variations in factory tolerances) with the advantages of shorter over-travel and more detectable trigger reset.
Expected Results
– Reduces trigger pull by approximately 2 lbs.
– Smooth uptake and reset
– Reduces reset length
– Reduces over-travel
In The Package
Fully machined .45 Sear
Ultimate Striker Block Kit
Ultimate Striker Block
Striker Block Spring
Talon Tactical tool
Shield Carry Spring Set
Sear Spring (1/8")
Slave Pin (to assist with trigger return spring installation)
Rated Trigger Return Spring

The kit has made a big difference in the overall trigger feel on my Shield which had a lousy trigger from the factory. I wanted a way to improve the trigger feel without doing a complete trigger change.

A smoother operation, lighter trigger pull, no more grittiness, crisp and clean break and reset.

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M&P 9, Shield9.

Apex Tactical is great. Glad they were able to fix your issue.

I had FrogLube cause failures (completely inoperable actually) in an AR15 type rifle.

Don't use Froglube on anything that matters.

*
We have a winner. Nothing harsh, works great. It was recommended to me by one of the foremost trainers on the AR platform and I have had nothing but success with it. I use little if anything else for all of my firearms.

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NHI, 10-8.