Howdy

[Albroswift]

No problem on replacing the parts mentioned, doesn't sound like any big deal, and I'll get some more photos tonight. Really appreciate the help.

PS

As far as handloads, I have been handloading for about 100 years, 22 hornet to 45-70, and load 308 for 2 other rifles. I use a 2 die system to size to the guaged bore, press mounted trimmer/ trimmer die to length, hand chamfer, case guage,  polish the brass before and after sizing lots of lube, hand chamfer and inspect every round,  electronic powder dispenser, collet crimp die, etc etc  so I will venture to say  that my loads are tip top. :)

Thought the extractor might not like the used rims so I did try factory and some brand new brass, same results. 

 

 

[Albroswift]

Where do you guys like to shop for said parts?

[Albroswift]

Wow everybody is out of stock!

 

[DNP]

I'm guessing 98 bought them all. He's only had a dozen builds this month and that's his go-to setup. 

[Albroswift]

Arghhh...

[Albroswift]

19 hours ago, 98Z5V said:

gas tube, in the upper, with the BCG removed.  I wanna see where it's at in the receiver, and how much it protrudes into the upper...

 

Here it is

[Albroswift]

19 hours ago, 98Z5V said:

gas tube, in the upper, with the BCG removed.  I wanna see where it's at in the receiver, and how much it protrudes into the upper...

 

Here it is

[Albroswift]

On 7/10/2018 at 9:05 AM, Matt.Cross said:

That's physically unpossible my friend. You're saying that in the firing sequence, the bolt extracts the fired round(evidenced by the case mouth being dented by the locking lugs on your barrel extension), strips another cartridge from the mag, and then chambers the stripped cartridge with the spent cartridge trapped behind it. That's physically impossible.

Based on the pics and the bent cartridge here is what I see happening when this occurs; the bolt fails to travel far enough rearward to properly strip the next cartridge, and begins to travel forward again before the extracted brass can clear the receiver. On the way forward, the bolt frictionally grabs the cartridge in the mag and pushes it into the barrel extension locking lugs where it bends and ceases to move, the bolt continues forward stovepiping the spent brass.

That's my assessment.

Not exactly

Hello, Matt

The spent cartridge ends up ON TOP of the live round, not behind it.  If I put one round at a time in the mag the bolt locks back 100% of the time, even with my weakest load--150 gr @ 2275 fps. The photo is staged because I didn't think of taking the photo when it actually happened, but if you want to look at the photos I posted down towards page 2 the actual spent rounds they have a round mouth if that makes any difference. It is more like the round is bouncing out and then bouncing back in, if that is even possible, or releasing from the extractor too early and flipping sideways. Never had anything like this in my Colt SPII or my BAR 338. Thanks for the help! 

[DNP]

If your carrier is traveling all the way to the rear, but the spent casing is not being ejected....something is up with the ejector/extractor. 

[Albroswift]

7 minutes ago, DNP said:

If your carrier is traveling all the way to the rear, but the spent casing is not being ejected....something is up with the ejector/extractor. 

That is what I thought, but I have never seen the spent round sticking out sideways like that on other rifles. Butt end of the spent round is all the way back against the left side of the upper.

[DNP]

I'll let the experts say for sure, but if it's not spitting it out reliably, my guess is something is wrong with some of the minor parts. I'd try replacing those first...they're cheapest. If that ain't it, you're not out much. 

[DNP]

Could just be a piece of crud in it as its intermittent. You've ruled out ammo I think. It does the same thing with different brass. It's not grabbing something consistently or holding on too long. 

[DNP]

Not exactly the same, but I'd bet money his issue was pretty similar. 

 

[Robocop1051]

i Agree with DNP. Open up that bolt and take a look. 

[Albroswift]

48 minutes ago, DNP said:

I'll let the experts say for sure, but if it's not spitting it out reliably, my guess is something is wrong with some of the minor parts. I'd try replacing those first...they're cheapest. If that ain't it, you're not out much. 

Found a VLTOR tube and EA1095 spring at DSG, try that fist and let you know. 

Video similar, except 100% of my fails are case mouth straight out, butt tight to the left side of the receiver. Good video, shell bouncing around but not leaving the port. Wonder if my android phone would film that fast.

[Albroswift]

2 minutes ago, Robocop1051 said:

i Agree with DNP. Open up that bolt and take a look. 

Broke it down completely after several of the fails. New and clean looking. Heavy rubber doughnut around the extractor spring, don't remember my Colt AR 15 BCG having that. See how the new tube/ spring/ buffer work out. I'm obviously not an expert, but maybe the jar from a weak spring slamming to a stop could be the issue.

[Matt.Cross]

1 hour ago, Albroswift said:

The spent cartridge ends up ON TOP of the live round, not behind it. 

Gotcha. Here is what I was basing that on...

 

On 7/10/2018 at 8:31 AM, Albroswift said:

It is running back plenty far, it chambers the next round and then jambs the spent round on top of it.

I think I understand your problem now...

 

When the failure occurs, is the bolt behind the fresh round, or on top of it?

[DNP]

I'm still going with ejector. You'll have a damn fine recoil system, but that ejector or the spring is jacked in some manner. 

Edited July 12, 2018 by DNP

[98Z5V]

4 hours ago, Albroswift said:

Here it is

Need to see straight down into it, man - like this:

 

[Albroswift]

8 hours ago, Matt.Cross said:

Gotcha. Here is what I was basing that on...

 

I think I understand your problem now...

 

When the failure occurs, is the bolt behind the fresh round, or on top of it?

Hi, Matt

Bolt face is behind the fresh round

Thanks

[Albroswift]

6 hours ago, 98Z5V said:

Need to see straight down into it, man - like this:

OK, tonight!

Thanks

 

 

[Albroswift]

7 minutes ago, Albroswift said:

Hi, Matt

Bolt face is behind the fresh round

Thanks

One time I dropped the mag, pulled the spent case, live round finished chambering. Most of the time however it is too deformed and if I let it try to chamber it gets moderately stuck, but, the extractor is engaged and will pull it back out. If I pull the bolt back first, then drop the mag, the live round is not extracted but will pull out with fingernail.

[Matt.Cross]

3 hours ago, Albroswift said:

One time I dropped the mag, pulled the spent case, live round finished chambering. Most of the time however it is too deformed and if I let it try to chamber it gets moderately stuck, but, the extractor is engaged and will pull it back out. If I pull the bolt back first, then drop the mag, the live round is not extracted but will pull out with fingernail.

I'm pretty sure your recoil cycle is way too brief, needs to be a bit longer. That's a two-factor problem, the right gas system setup is the first component, and a heavier bolt carrier group is the second. I would address them in that order.

[Albroswift]

3 hours ago, Matt.Cross said:

I'm pretty sure your recoil cycle is way too brief, needs to be a bit longer. That's a two-factor problem, the right gas system setup is the first component, and a heavier bolt carrier group is the second. I would address them in that order.

Thanks Matt,  that's where most of this information seems to be pointing and it makes sense. I have the longer tube  and spring on order so that should give me some more direction.

When you say a heavier bolt carrier group, could/would you include the buffer weight in that calculation?

PS great forum, I don't think I have ever received this much help on the interweb EVER!

[Matt.Cross]

25 minutes ago, Albroswift said:

When you say a heavier bolt carrier group, could/would you include the buffer weight in that calculation?

Definitely. Heavier buffer = more cycle time.