SP10 Not Ejecting - slomo video

[zekers7]

Swapped out the factory Magpul PRS stock on my SP10 for a collapsible setup.

Current Specs:

• LMT MWS buffer tube (a5 length)
• Factory SP10 flatwire spring (rifle length)
• H2 carbine buffer
• 6.5 Creedmoor
• Seekins adjustable gas block

The issue I’m running into: every ~20 rounds or so, I’m getting a stovepipe or FTE. It was worse with the standard gas block, but after swapping in the Seekins adjustable and dialing it back, the rifle is cycling more smoothly—but the issue still pops up once every 20 rounds or so.

Any ideas?

 

[wvfarrier]

I would swap out ejector. It appears not to be grabbing the casing. Try swapping to one of KAKs dual ejectors. It fixed the issue with my DD 308.

 

[hlee]

Could also be a shitty extractor that isn’t gripping the case well as it is pulled out of the chamber. For the record, ejectors are the plungers that push the case off of the bolt face. Extractors are the hooks that pull the case out of the chamber.

 

[zekers7]

Maybe im missing it - does it look like the extractor/bolt is slipping off the case? Or is the case just not ejecting in time

 

[hlee]

Maybe im missing it - does it look like the extractor/bolt is slipping off the case? Or is the case just not ejecting in time

Doesn’t look like the case is getting kicked at all. I rectified a similar issue with a stiffer extractor spring. Seems like, if the extractor isn’t holding onto the case well, the ejector really can’t kick it out…

 

[loveha]

One of two like already mentioned. Weak ejector spring, or dull extractor claw. Also check to see if there is an O ring around the extractor spring.
Watching it several times, it looks like ejector spring because the brass is not trying to angle out at all as it is being extracted past the ejection port. It comes loose from the extractor as the BCG slams into the back of the buffer tube.

 

[db2000]

SP10 has dual ejectors iirc

 

[zekers7]

I’ll try out two other BCG I have laying around to see if it can be isolated. Also stepped up to a h3 buffer

 

[zekers7]

Doesn’t look like the case is getting kicked at all. I rectified a similar issue with a stiffer extractor spring. Seems like, if the extractor isn’t holding onto the case well, the ejector really can’t kick it out…

Pulled the extractor from my bolt and compared it to both an LMT and another AR-10 BCG I had on hand. Mine had noticeably softer tension — could reinstall it with very little pressure — while the other two had much stiffer extractor tension.

Seems like a weak extractor spring could be a good starting point - Appreciate the input so far.

 

[sinister]

It appears to be extracting fine, all the way until the BCG hits the end of the receiver extension.

It looks to me like your ejector springs are not kicking out the ejector plungers at all.

 

[cas6969]

• H2 carbine buffer

My default answer to everything is "too fast".
The fact that cutting down the gas helped somewhat backs that up.

What exactly do you mean by H2 carbine buffer.
Because if you really meant an H2 5.56 spec carbine buffer somehow, then yeah, too fast.

 

[bfoosh006]

I could be wrong... but...
If you decide to replace the ejector springs ( on a Dual Ejector bolt ) be careful not to loose the ejector retaining pin... since it is possibly "proprietary" to the bolt design.

IE... it is possibly longer than usual, since the dual ejectors are spaced wider in the bolt.

It is also possible that the ejectors orient 180 degrees differently... and the retaining pin just holds them on the "other side".

 

[zekers7]

My default answer to everything is "too fast".
The fact that cutting down the gas helped somewhat backs that up.

What exactly do you mean by H2 carbine buffer.
Because if you really meant an H2 5.56 spec carbine buffer somehow, then yeah, too fast.

Carbine H2 5.56 buffer. Tried to mimic the SR25 setup (A5 tube, rifle spring, carbine buffer)

 

[zekers7]

It appears to be extracting fine, all the way until the BCG hits the end of the receiver extension.

It looks to me like your ejector springs are not kicking out the ejector plungers at all.

Whats strange here is they seem to have decent tension. Looks like i may need to just try and isolate the problem one fix at a time. Ill report back with findings. Starting with a heavier buffer

 

[hafejd30]

I had a similar issue with my 556. In my case it ended up being the extractor. Weak spring and was dropping the cases before it had a chance to eject.

Dropped a rubber O-ring on the spring side of the extractor. Solved my problem

 

[White_Shark]

It’s a Seekins, call them and tell them what the problem is and they will make sure you are taken care of. Some of the absolute best people in this industry.

 

[db2000]

It’s a Seekins, call them and tell them what the problem is and they will make sure you are taken care of. Some of the absolute best people in this industry.

^^^this