Rounds not fully chambering

[lovetabike]

Trying to get my AR-10 .308 to cycle better. Before I list all the components I was wondering if my issue is more general. When charging it at times 2 or 3 times to fully chamber.  When I do get it to fully seat it cycles ok. Once in awhile a round again won't fully chamber. The bolt It's about 1/4 inch from fully closing. 

I'm using JP enterprises Gen 2 silent capture system with the lightest spring in case anyone is familiar with that.

Not much info but I can add more detail if someone might have a trouble shooting direction. I re load my own with an oal of 2.75 .

 

[98Z5V]

You setting the shoulder back on that reload, and bulging it?  Is this a reloading issue, or is it a Chamber issue on the barrel?

Listing the rifle specs will be pretty much mandatory, for this.  It's gotta happen.

Haven't hear of too many Armalite AR-10s with tight chambers before, but there's always a first.

[Sisco]

Is it an Armalite? Using JP Enterprises parts guessing it might actually be a DPMS pattern. Also listing components, sounds like a build, so probably not Armalite. Buy some factory ammo to make sure it is not an issue with the reloads. Were those reloads brass reformed with small base dies? If they were shot in another 308 and just neck sized, that could be your problem right there. With 308ARs small base dies are almost mandatory.

[lovetabike]

It's DPMS pattern. Using RCBS small base dies. Using Hornady cartridge gauge after resizing. The cases are once used brand can't recall the brand but I did a full resize on them to make sure.

Mega Matten upper/lower / Christensen arms .308 carbon fiber wrapped barrel / fulton arms high pressure bolt carrier group. 

I'll buy some factory amo and see I get the same results. 

 

 

[Sisco]

Good place to start. AR10’s is Armalite nomenclature, everything else is 308AR.

[98Z5V]

34 minutes ago, lovetabike said:

It's DPMS pattern. Using RCBS small base dies. Using Hornady cartridge gauge after resizing. The cases are once used brand can't recall the brand but I did a full resize on them to make sure.

Mega Matten upper/lower / Christensen arms .308 carbon fiber wrapped barrel / fulton arms high pressure bolt carrier group. 

I'll buy some factory amo and see I get the same results. 

 

 

...

Edited May 20, 2018 by 98Z5V

[98Z5V]

7 hours ago, lovetabike said:

It's DPMS pattern.

 

Then it's definitely not the AR-10, man.  Check a single round, by hand, see if it slides right in to the chamber.  It should, and if it does, it rules out the tight-chamber theory right away. 

Edited May 21, 2018 by 98Z5V

[edgecrusher]

My first question now that we have info is did you headspace the bolt? Next is how much lube are you using???

[308kiwi]

8 hours ago, lovetabike said:

I'm using JP enterprises Gen 2 silent capture system with the lightest spring in case anyone is familiar with that.

I'd try it with the heavier spring first, JP make a 'tune kit' of springs for their captured thingy ma jig, try the heaviest spring. Could well be that the BCG just isn't being driven into battery with enough momentum. It's the last little bit of travel that requires the most energy, when the BCG has to overcome the extractor and the ejector.

 

[lovetabike]

I had the head space checked at a local gun shop. 

I had a heavier spring in but the cases were not fully ejecting and the bolt wouldn't lock out after the last round. Things were pretty tight right after the I did this build last fall but now after hundred rounds or so and lubing it correctly it's much better. I'm going to pop in the middle height spring and see what happens. If it's not better I'm going to have the head space checked out just in case.  

[edgecrusher]

Random question, adjustable gas block?

[98Z5V]

^^^  If it is, Wide-Open that thing for any future testing, until there's solid function...