Ejector Swipes with Large Frame AR's

[wareagle700]

Do you get ejector swipes with your .308's and other large frame AR cartridges? If so, why do you think it happens? Does it have to do with many .308's being over gassed or the location of the gas port on many .308's causing early unlocking?

After you hit the poll, please post a yes or no along with a detail description of your barrel, gas system, and BCG.

Thanks.

 

[Regalkismet]

An adjustable gas block and the appropriate buffer/spring go a long way in getting rid of swipes on your brass....i use a Syrac adjustable gas block, JP silent captured spring with tungsten weights, YM NM 308 carrier and a JP bolt and barrel.

 

[jasonfaz]

I put yes, but don't anymore. About 8 months ago, I finished up a .338 Federal with 18" mid length gas, SLR block, JP BCG, JP barrel, with matching bolt and tried numerous buffers/springs in both standard carbine and A5 lengths. No matter what I did to the gas adjustments, springs, buffer weights, I still got heavy case swipes. I was left with one last fix, as occasionally those types of signs could be false pressure signs as it relates to gas system issues and really be false pressure signs related to something outside gas pressures entirely. In my case, I had simply torqued the barrel nut for my Fortis handguard down too tight which caused some funky cycling issues. I hadn't really thought about it before and didn't realize that you really, really don't need a huge amount of torque to ensure the barrel nuts won't move.

So if you're trying to figure it out and have run through the gas adjustments, buffer/spring changes, etc. Try removing and reinstalling the barrel nut and inspect the extension while you're at it. It made all the difference for me.

 

[LawnMM]

Had em from day one with my 6.5CM. Its a timing issue since none of the other pressure hallmarks are present and I'm well under published maximum load. It also improved slightly when I added weight to the cycling components. Switched to a standard carrier from a lightweight, slash's ultra heavy buffer and spring, it improved but is still present. I think its something that on my rifle would only be fixed by moving the gas port or adjusting its size and neither are worth the trouble, frankly. So mine is just going to be a bit rough on the brass, it happens. The bigger problem I have is the Hornady brass, the pockets loosened up rather quickly and I'm sure its not all the brass' fault, unlocking early is removing support from the case head...if that's what is causing it. I'll get 4x firings on it though so the swipes are present, but tolerable.

I'd also point out they aren't swipes in the conventional sense where you get a smear or a clear print of the ejector. Its more like a crescent moon shape from the ejector gouging past the brass as the bolt unlocks before the case has cooled sufficiently and shrunk from the chamber wall.

 

[wareagle700]

Jasonfaz,
What relation did the barrel nut tightness have with the false pressure signs? I am having a hard time understanding that one.

Do the JP LRP-07's experience this? I was using a full mass NiB carrier with JP bolt and getting light ejector swipes. I have since switched to a complete JP LMOS BCG along with the JP Silent Captured Spring setup and Syrac adj. gas block. I have not fired it with the new BCG yet but I didn't know what to expect.

 

[Mike_in_FL]

I voted No, but have gotten swipe marks before. After re-barreling I ran a JP low mass carrier and even readjusting the JP gas block I had marks. Installed my original BCG and running the Tubbs weights brought it back to normal, no signs of swipe. Running an UBR with flat spring and Slash heavy buffer. It all seems to be if it's unlocking too quickly in my case.

 

[pby5cat]

I have a fulton armory in 6.5 creedmoor and have always has ejecter swipes on hornady 140gn ammo and duplicate reloaded ammo. I also get primer flow around the firing pin. I know if i reduce the load by .5gn the problems go away. i tried slash heavy buffers ans springs with no help.

 

[Regalkismet]

Jasonfaz,
What relation did the barrel nut tightness have with the false pressure signs? I am having a hard time understanding that one.

Do the JP LRP-07's experience this? I was using a full mass NiB carrier with JP bolt and getting light ejector swipes. I have since switched to a complete JP LMOS BCG along with the JP Silent Captured Spring setup and Syrac adj. gas block. I have not fired it with the new BCG yet but I didn't know what to expect.

You may want to consider the tungsten weights for the silent captured spring if you are still having an issue but with the LMOS carrier you may be gtg.. They are not on the webpage... You have to contact JP and ask for them.