Iron Ridge 308 Build - Ejection Issues????

[smfourie]

So I thought maybe I could get a little help here with a 308 I built.

Specs are:
Fulton 18.5" Barrel with rifle length gas system
Gas Block Paladin Machine adjustable
DPMS BCG
Vltor extended buffer tube
H3 buffer
Armalite Buffer spring

I'm having hell with ejection issues and I thought maybe I could get some help from you guys. Below are 2 videos showing how the spent casing are behaving. Any help is appreciated.

 

[ponchair]

Re: Iron Ridge 308 Build - Ejection Issues????

Bolt in the wrong way?

Extractor facing the wrong way?

 

[ponchair]

Re: Iron Ridge 308 Build - Ejection Issues????

Also check the ejector, make sure that it can be pushed down, and springs back up.

 

[smfourie]

Re: Iron Ridge 308 Build - Ejection Issues????

The extractor and ejector both look good. It just doesn't want to throw the rounds straight out the side?????

 

[Phylodog]

Re: Iron Ridge 308 Build - Ejection Issues????

Looks like the case may be coming out from under the extractor early? See if you can find a small rubber o ring which will fit snug over the extractor spring and buffer. That should increase the pressure the extractor exerts on the rim and hold it better.

I don't think this will fit but it gives you an idea of what to look for anyway:: LINK . I haven't had a .308 in my hands in awhile and can't remember if the extractor spring is larger/longer than the 5.56.

 

[Massoud]

Re: Iron Ridge 308 Build - Ejection Issues????

That appears to be a classic case of too high carrier velocity. Here's what happens: As the bolt/carrier comes back, the ejector starts swinging the empty case out of the ejection port. However, before it can get the case very far out, the bolt/carrier is already back to the brass deflector. So the case hits the brass deflector at the extreme wrong angle and you get what you see in the vids. The case bounces back into the breech area.

The solution, well generally you have either a weak ejector spring, or your gas port is too large. First switch out the ejector spring. If this doesn't work, you have to slow down the carrier. Really the only way to do that is to add weight to the buffer, I would get the heaviest one you can find. Of course you can put on a new barrel with a smaller port. One indication of too high carrier velocity is to check the rim of the empty cases and look for marks where the extractor almost tried to pull the rim off (varying degrees of distortion of the case rim of course).

People tend to think this is extractor related, and sometimes it is, but rarely. Of course it never hurts to swap out your extractor and/or extractor spring. Usually with a bad extractor you'll see a case left in the chamber or a slightly different type of malfunction.

 

[Mike_in_FL]

Re: Iron Ridge 308 Build - Ejection Issues????

You didn't mention what kind of buffer spring you're using, but you've definitely got an AR-15 buffer. As was already suggested to you, reduce the gas with your adjustable block or get a heavier buffer and AR-10/.308 spring.

 

[Jumper]

Re: Iron Ridge 308 Build - Ejection Issues????

You've got the Palladin adjustable gas block, try less gas before you add weight to the carrier.

 

[Massoud]

Re: Iron Ridge 308 Build - Ejection Issues????

I missed that you had an adjustable gas block, try that of course first. Put one round in a mag, fire it, and see if the bolt locks back. Keep turning the gas down until the bolt doesn't lock, then bring it back up a bit. I'm not familiar with that gas block so this only works if you've got many positions.
Justin

 

[ST42]

Re: Iron Ridge 308 Build - Ejection Issues????

I just had this issue with a build. For my rifle, it was a combination of two things.
1. My extractor claw had a bur on it that has hanging onto the case rim.
2. My extractor spring had the O-ring around the extractor spring.
I removed both, and I now have 3-3:30 ejection and it slings the cases about 8 feet out.

 

[Guest]

Re: Iron Ridge 308 Build - Ejection Issues????

I had a very similar occurrence with my IRA build and contacted Oliver with Iron Ridge directly. I was sent a new upper as a result. Very good guy to work with!!

I mention this only because I went through the same issues with banging my head against the wall, replacing extractor claws, buffer springs, extractor springs, gas tubes, etc and couldn't figure out what the hell was wrong. Ultimately it appeared that the ejection port opening was a bit low, not allowing for the spent case to eject properly. Had no idea until actually measuring.

Call Oliver, highly recommended. Don't give up on IRA just yet...here's my finished baby:

 

[Massoud]

Re: Iron Ridge 308 Build - Ejection Issues????

How much low, if you don't mind me asking. Really you should have quite a bit of wiggle room to where being low by 10 or 20 thou would be negligible.
Justin

 

[Casey Simpson]

Re: Iron Ridge 308 Build - Ejection Issues????

Shawn, do this:
1. separate the bolt from the carrier.
2. separate the extractor from the bolt.
3. polish the area of the extractor that slips over the case rim - the area you see while looking straight on at the bolt face. Polish by hand using 400 ~ 600 sandpaper. You may accomplish this without separating the extractor from the bolt.
4. separate the ejector from the bolt. Polish all surfaces of the ejector either by hand or by chucking it in a small powered driver and using sandpaper in the other hand. This is not a major machining operation - not to alter dimensions.
5. do the same thing to the ejector spring.
6. wrap a piece of sandpaper around a toothpick and polish the interior of the ejector well.
7. polish the barrel chamber.
8. polish the bolt face while you have the sandpaper and driver handy. Simply chuck the other end of the bolt in the power driver or drill while you hold something like a pencil eraser head under sandpaper against the bolt face, oiled, for polishing to avoid gauling between the bolt face and case head. A parkerized bolt face is ignorant of a builder.

Remember and use oil on the surfaces while polishing. Apply any grease to these parts and their retaining pins and springs and put them back together.

In case someone hasn't figured it out, we're polishing to remove burrs and tooling mars that might be causing hangs or snags.

If your semi insists on failling to eject, and its not ammo, magazine related, or too long of a buffer spring, try stretching by a few millimeters the ejector spring using two pieces of 20lb test line.

Now, lubricate the cam pin, bolt lugs, and carrier rails with grease. Grease is superior to oil because it will slow the velocity of the bcg, it stays put better and thus lasts longer and doesn't leak down onto the ammo in the mag and catch a ride into the chamber to cause otherwise unexplained pressure issues. Won't hurt anything to apply a little grease to the buffer spring too particularly in these big chassis AR's. Grease the bolt lugs, but not so much that grease ends up piggyback onto your ammo into the chamber. Just be reasonable.

I notice you're in Texas and Summer is coming. Use gear oil on the hammer and trigger pins and sear. Mix with grease and graphite or boron nitride for the sear / hammer contact surface. Slick as owl shit!

P.S. These genius ideas are not my own. They came from Glenn Zediker, in my view, the senior most AR expert.

 

[problemchild]

Re: Iron Ridge 308 Build - Ejection Issues????

Seems like its getting too much gas to me and bouncing the brass back into the from of the ejection port. Tone it down.

 

[Casey Simpson]

Re: Iron Ridge 308 Build - Ejection Issues????

problem, it looks that way too. But usually Lr's throw brass too far. ??

 

[Casey Simpson]

Re: Iron Ridge 308 Build - Ejection Issues????

I'm watching the vid again and I agree with Ninja, but also because I've had the same experience and the cause was a snagging ejector. I had had the bolt bushed and the smith left a bur in the ejector well snagging the spring. Easy fix.

 

[smfourie]

Re: Iron Ridge 308 Build - Ejection Issues????

Thanks everyone for the comments. I will give everything a try. I don't want to give up on this build. This is going to be a great shooter if I can only make it reliable.

 

[smfourie]

Re: Iron Ridge 308 Build - Ejection Issues????

I'll start by Calling Oliver at Iron Ridge and see if I'm out of spec. After that, I'll get a fully adjustable gas block from PRI or JP. That way I can do all the adjustments at the range swapping out buffers, springs, o-rings, etc... If I can get it to work properly I'll get a new drum from Paladin and have the smith slowly bore out the has port holed until we have the right settings for low pressure and high pressure.

 

[bburnham]

Re: Iron Ridge 308 Build - Ejection Issues????

I had a very similar appearing problem with my Iron Ridge upper and lower build, using DPMS parts. The empty was not being pushed off the bolt face consistently. Tried a bunch of things, then checked the ejector spring that came in the DPMS bolt, turned out to be an AR 15 spring. Changed it out and it hasnt hiccuped(sp?) in several hundred rounds. Easy fix to try.