Transferable FNC S&H Sear Gun Problems

[LRM1981]

I purchased an S&H sear gun about a month ago and was able to bring it to the range over the weekend with my dealer who's doing the transfer. I had the gas set on setting one for the first shots, but the gun would short stroke. After switching to setting two, the gun seemed to function better, but the rate of fire was slower than I was expecting. After about 3 mags, the gun started to get stuck cases consistently after about 5-10 rounds. One was so bad that I had to remove the upper and pound the charging handle with a dead blow hammer to get it unstuck (I cringed when I had to do this).

Pretty disappointing first run with the FNC. I know it's probably hard to tell what's going on with the gun without looking at it, but would this possibly be a headspace issue? I'll probably have it sent out to a gunsmith while I'm waiting on the transfer, but I'm not sure who at this point. Is S&H still in business, or do you guys recommend someone else for FNC work? I do have another semi auto FNC as a backup if need be, but I'd rather not use that as a sear host.

Thanks in advance.

Here's a video of some of the issues:

 

[Haris1]

The rate of fire in mine is 615(using a timer) slower than M16 but way more controlleable wuth less muzzle rise.
If it fired faster with rounds going over the target, what good is that?

 

[dubagel]

Sandharms.com, fortunately for you, yes they are still in business with Curtis Higgins. According to their website.

 

[LRM1981]

The rate of fire in mine is 615(using a timer) slower than M16 but way more controlleable wuth less muzzle rise.
If it fired faster with rounds going over the target, what good is that?

I was just expecting the rate of fire to be faster with the gas system in setting two, not that I wanted the gun to run faster. I have other MG's that are overly fast, so I like the slower ROF with the FNC.

 

[rparsons3]

FNCs need strong mil spec ammo, I had mr. Higgins convert one for me and it acted just like yours unless I used imi or federal mil ammo. Had another one that TBA suppressors converted for me and I had him drill out the Belgium set screw and install sae set screw so I could adjust gas instead of using the flip switch on gas system. Look up TBA suppressors website he is a good guy.

Small edit..be careful with the fnc charging knob, I have read several times of them breaking off, a scar charging knob will fit if you cut off the length of the part that inserts into bolt, they look different but will fit, I never needed one but keep scar knob as spare, and I bet the key word in your post is Aguila. When I bought my first fnc about 12 yr ago they were really popular and there was more post on here about them, should be some good info in old threads....oh do clean it and scrub chamber good if the previous owner did not keep it clean, good luck, I really like fnc although I never shot either one very much, sold both and now down to m16. YMMV of course.

 

[LRM1981]

FNCs need strong mil spec ammo, I had mr. Higgins convert one for me and it acted just like yours unless I used imi or federal mil ammo. Had another one that TBA suppressors converted for me and I had him drill out the Belgium set screw and install sae set screw so I could adjust gas instead of using the flip switch on gas system. Look up TBA suppressors website he is a good guy.

Thanks for the info, maybe I'll reach out to TBA Suppressors as well - I need to buy a burst kit for it anyway. I believe the first couple of mags I tried were with Federal M193 and PPU M193 which worked well, but would still only cycle with it on the adverse gas setting, otherwise the bolt would short stroke. I think the problems started to happen with Aguila 5.56 which was probably not as hot or consistent and most likely softer brass which lead to the stuck case. I have a bunch of at hot IMI ammo, so maybe I'll give that a try next time. Good idea.

I'm going to have a gunsmith friend of mine look over the gun. It probably needs a good cleaning too, as the previous owner just put it away in his safe without a proper cleaning (probably sat there for many years).

 

[sweersa]

I too recommend staying away from Aguila. It's garbage, at least in 5.56/.223 in my experience.

Even my SL8-1/G36K has issues with it, and that thing eats everything else. (I never run steel in my 5.56 guns though, that's for my dirty communist guns) Same with my brother's Ruger 556, no bueno with Aguila, though our issues with it were related to their primers and or primers placement.

 

[rsideout]

Thanks for the info, maybe I'll reach out to TBA Suppressors as well - I need to buy a burst kit for it anyway.

Todd did the conversion, burst kit, and 14" barrel on my FNC. It needed a little tweaking after I got it and he stood behind things 100% and got it right. Also look at the FN engraving that he can do on the receiver. I think that it gives the gun a more modern updated look.

 

[Blitzy]

I've never had short stroking issues with my FNC, and I primarily use wolf gold .223 and Remington UMC .223. I do however have occasional issues with the three round burst light striking on the second or third round, but I suspect that is a problem with my burst assembly vice a gassing issue. Here is an example of the light strike when I first got mine, it went through about 1/3 the magazine in full auto before on cartridge decided to not sound off. https://youtu.be/EYmVZcpZNc8?list=TLPQMjYwMzIwMjHby2FCm5q1_A Good luck with your issue and let us know how it goes.