New forum member, old question on the Silent Capture Spring

[Riskyjim]

Hello, I'm new to the forum and I have a question on the SCS system. I am running a Stag Arms Model 3 lower mated to a Radical Firearms 16" upper, pistol length gas system. SilencerCo Omega suppressor. I put a gen 1 SCS on the gun and I am getting about a 33% rate of failure to fire. I sent out the Timney trigger to have them upgrade the springs/hammer to the AR10 configuration, swapped out the standard steel firing pin to a high end titanium pin. Scraped out the bolt to ensure no carbon build up, cleaned and lubed the thing up well and checked the headspace and my gunsmith checked the chamber and it is in spec. It was working perfectly before the SCS upgrade. I'm getting definite marks on the primers, but still the fail to fire occurs in about 33% of rounds. Using just the Remington 220gr factory subsonics. I just received three new tungsten weights and have yet to put them on. Just wanted any feedback before replacing the steel for tungsten on the SCS. Any thoughts to cure my rifle? The SCS quiets this down so that the loudest thing about this rifle going off is the bolt closing and the trigger reset. It's had about 250 rounds out of this configuration and doesn't seem like it's on the road to reliable function.

[bangbangping]

Welcome to the forum. We're currently having some issues that can result in duplicate posts. Please read this: viewtopic.php?f=128&t=98558

As for your issue, is is not locking up? Does it work again if you go back to a standard buffer and spring?

[TMD]

If I'm reading your post correctly it sounds as if its feeding ok just not firing. If so the SCS has absolutely nothing to do with your problem. Also not understanding what an AR10 configuration is for your Timney trigger is. Last time I looked the AR15 and AR10 platform use the same trigger. From the way you're describing the problem it sounds as if the hammer spring is too light. Toss in a lightened firing pin and it just compounds the problem.

[SwampDog_13]

I'm with TMD, if the round is making it into the chamber the jp scs is doing its job. Now what the failure and the buffer changes have in common would be the question. Is the bolt carrier group making it all the way home when chambering? Have you tried hitting the forward assist after chambering and seeing if that makes a change in the firing percentage?

[A-Game]

https://www.youtube.com/watch?v=kfCUjjA2F4U

Your BCG might be the culprit and a sign of future failures.

I use the Gen 1 JP silent spring and haven't had a failure to fire from a light primer strike.

[tXr]

The SCS has absolutely no impact on your light primer strike issue, 99% of the time it is the result of having a upgraded trigger/hammer installed and then trying to run NATO spec primers(like Rem 220gr ammo), the light hammer spring(what generates 90% of the felt trigger weight) simply isn't reliable enough.

Also not understanding what an AR10 configuration is for your Timney trigger is. Last time I looked the AR15 and AR10 platform use the same trigger. From the way you're describing the problem it sounds as if the hammer spring is too light. Toss in a lightened firing pin and it just compounds the problem.

Timeny does have a AR10 kit, every large frame rifle requires a heavier hammer spring due to the thicker standard large rifle primer used in 308Win.

The lighter firing pin does NOT exacerbate the problem but actually helps by speeding up the firing pin's rate of acceleration to increase it's inertia when striking the primer when running lighter hammer springs.