LR 308 Malfunction

[d33rhnter]

Is there a term for this malfunction? I'm decent with the search bar but coming up with a search term for this has me stumped.

The rifle is a home-assembled LR-308 chambered in 308 and suppressed with a Silencerco Saker. It has a 16” barrel with a rifle-length gas system and adjustable gas block. The buffer system consists of a JP Silent Capture Spring with the lightest spring and a standard carbine tube.

Thanks for your time.

 

[alamo5000]

I would bet on it being over gassed.

 

[MarshallDodge]

It looks to me like a weak ejector spring or the extractor is loosing control of the case

 

[nagantguy]

Over gassed.

 

[bfoosh006]

Attach a fuzzy side of adhesive backed Velcro to your empty case deflector .... just to see if it is some how bouncing off it , and back towards the ejection port.

You aren't running a empty case catcher are you ? My 9MM PCC kept bouncing the fired case back into the action, with a case catcher.

And all the other suggestions have valid points.

 

[d33rhnter]

Attach a fuzzy side of adhesive backed Velcro to your empty case deflector .... just to see if it is some how bouncing off it , and back towards the ejection port.

You aren't running a empty case catcher are you ? My 9MM PCC kept bouncing the fired case back into the action, with a case catcher.

And all the other suggestions have valid points.

Thanks for this input. I’ll keep a close eye on the angle the case deflector is sending casings while adjusting the gas. Not running a case catcher. I’m shooting off a bench in the open with nothing near that could bounce the casing back towards the rifle.

 

[mettee]

Not again

 

[mettee]

....The buffer system consists of a JP Silent Capture Spring with the lightest spring and a standard carbine tube.

This

 

[1911hombre]

Term is "JPSCS-ing". Not sure on pronounciation.

 

[mewillis]

I would bet on it being over gassed.

Yep, time to start adjusting for clean 3-4 o'clock ejection unsupressed and I'm satisfied with 230-3 o'clock with an Silencerco Omega 300 on my Armalite.

 

[mettee]

Start with this:

1.) Are you shooting suppressed, if so what suppressor?
2.) What BCG do you have and what is the weight?
3.) What is your buffer weight?
4.) What is your buffer length?
5.) What is your Receiver Extension/Buffer Tube internal Depth?
6.) What is your Buffer Spring, Length, Coils, Brand, Color, etc?
7.) What is your Gas System Length- Rifle, Midlength, Carbine, Pistol, Other?
8.) What is your Gas tube Length, number 9 can help answer this?
9.) Take a Photo looking directly into the magwell that shows gas tube protrusion distance and post it.
10.) Take a Photo of the Bolt Face and post it.
11.) What is your BCG Clearance from the bolt stop under full compression?
12.) What is your Gas Journal Dia and gas Port Dia measured via wire drill size (If you can get it)?
13.) Photo and Description of the Malfunction or Issue.
14.) Any photos that are helpful, spent brass, etc.
15.) What ammo are you using, factory, hand loads, list specs?
16.) What lubrication are you using, grease, oil, etc?

 

[TheHorta]

It shouldn’t be doing that.

 

[bfoosh006]

Start with this:

1.) Are you shooting suppressed, if so what suppressor?
2.) What BCG do you have and what is the weight?
3.) What is your buffer weight?
4.) What is your buffer length?
5.) What is your Receiver Extension/Buffer Tube internal Depth?
6.) What is your Buffer Spring, Length, Coils, Brand, Color, etc?
7.) What is your Gas System Length- Rifle, Midlength, Carbine, Pistol, Other?
8.) What is your Gas tube Length, number 9 can help answer this?
9.) Take a Photo looking directly into the magwell that shows gas tube protrusion distance and post it.
10.) Take a Photo of the Bolt Face and post it.
11.) What is your BCG Clearance from the bolt stop under full compression?
12.) What is your Gas Journal Dia and gas Port Dia measured via wire drill size (If you can get it)?
13.) Photo and Description of the Malfunction or Issue.
14.) Any photos that are helpful, spent brass, etc.
15.) What ammo are you using, factory, hand loads, list specs?
16.) What lubrication are you using, grease, oil, etc?

That is a thorough list.

 

[FredHammer]

Another vote for overgassed. Very overgassed rigs can let the fired case linger in and around the ejection port causing this. A too fast BCG speed fucks with the ejector/ejection.

Oddly enough, your case head looks healthy though. Usually there is ejector smear/gouge.

 

[d33rhnter]

Start with this:

1.) Are you shooting suppressed, if so what suppressor?
2.) What BCG do you have and what is the weight?
3.) What is your buffer weight?
4.) What is your buffer length?
5.) What is your Receiver Extension/Buffer Tube internal Depth?
6.) What is your Buffer Spring, Length, Coils, Brand, Color, etc?
7.) What is your Gas System Length- Rifle, Midlength, Carbine, Pistol, Other?
8.) What is your Gas tube Length, number 9 can help answer this?
9.) Take a Photo looking directly into the magwell that shows gas tube protrusion distance and post it.
10.) Take a Photo of the Bolt Face and post it.
11.) What is your BCG Clearance from the bolt stop under full compression?
12.) What is your Gas Journal Dia and gas Port Dia measured via wire drill size (If you can get it)?
13.) Photo and Description of the Malfunction or Issue.
14.) Any photos that are helpful, spent brass, etc.
15.) What ammo are you using, factory, hand loads, list specs?
16.) What lubrication are you using, grease, oil, etc?

I’ll get a list together when I get back to the range in a few weeks. It’s been a few years since I assembled it and don’t want to give assumptions in a response.

Thanks for your input.

 

[d33rhnter]

Another vote for overgassed. Very overgassed rigs can let the fired case linger in and around the ejection port causing this. A too fast BCG speed fucks with the ejector/ejection.

Oddly enough, your case head looks healthy though. Usually there is ejector smear/gouge.

I’ll keep a close eye on the casings the next time I take it out to adjust the gas.

Thanks!

 

[mettee]

I’ll get a list together when I get back to the range in a few weeks. It’s been a few years since I assembled it and don’t want to give assumptions in a response.

Thanks for your input.

You answered some of them already, and from what everyone is seeing, I'm fairly sure about the issue but let's get all the info.

Since you are running suppressed we can focus on that. Both volume of gas and pressure is elevated beyond the intended parameters of the original design/set up. Your bolt is being pushed back harder/faster, so that needs to have an appropriate reaction on the other end(recoil system) or it speeds forward (after bouncing maybe) hitting that spent round before it can be sent on its way.

I'll fill in for Cascade hemi, "Yada yada heavy buffers suck." There we got it out of the way.