Has any one had experience with Azimuth's 308 double ejector bcg? I know toolcraft is the big name, but I've read that Azimuth is the the supplier for some reliable brands.
Azimuth technology Double Ejector BCG
- Thread starter Runnineh
- Start date
I have not. when I was shopping around for a top quality AR308 BCG, there were some big names that were recommended with some fancy features, one of them being a double ejector. I ended up going with a JP FMOS BCG with the HP bolt, it's the smoothest BCG I've ever handled. Zero issues. As a reloader, I don't know if i would appreciate a double ejector.
I reload as well, but this is my last ditch effort to get this thing to work. Its not ejecting (stove piping) . I've thrown everything I can think of and been recommended with at it.
What is the exact configuration of the rifle in question?
Barrel length
Gas port location and diameter
BCG
Buffer
Recoil spring
Chamber cut by ________ using _______ reamer
Ammunition
Stove pipe malfunctions are often either too fast of a cyclic rate, or short-stroke malfs.
Does your rifle lock back correctly on the magazine if you place only 1 round in a magazine?
Correctly means bolt lugs engaged by the bolt catch, not bolt catch on the carrier face.
You could buy just a bolt and use it in your existing carrier. Short of a defect in your existing Bolt, I cant imagine how a double ejector will help. Have you stripped the bolt down and inspected it?
Most of the time it's a gas/buffer/spring combo that is causing the problem.
-18" mid length gas
- DEZ barrel circa 2012
- Gas port was opened up, unsure to what
- Had a standard gas block, now have an adjustable (sup arms if I remember correctly)
- had a rifle buffer/buffer, switched to carbine with standard buffer, and now have heaviest buffer (slash)
-Had a standard ar10 spring, now have springco heavy spring.
-Had DPMS bolt, tried jp enhanced bolt
-tried 3 different mags
-switched to sprinco ejector spring
I've mixed all parts to try different configurations
It does lock correctly with one round.
It is feeding a round when it is stove piping.
When I had it suppressed, it wouldn't happen very often.
Happens with factory ammo and reloads. I tried to adjust loads and never worked.
I recently took it to a smith, and he said there's no point in giving it to him because I did everything he would do. (My first time in the shop and he didn't instill much confidence). I'm hoping the double ejector is the winner, but if you have any more suggestions, I'm all ears. Thanks and Merry Christmas
Do you have the correct gas tube length for MLGS so that the tube penetrates enough past the charge handle nose inside the upper?
It’s possible to have an ArmaLite MLGS length (longer) mixed with an incorrect AR-15 MLGS gas tube. They will generally run fine suppressed out-of-the gate, then start to malfunction with that configuration sometimes.
Is the gas tube flange worn down on one side from clipping the carrier key?
Is there any sign of gas leakage between the carrier key and the carrier?
Does your extractor have sharp corners on the lip?
Those need to be rounded if they’re sharp.
Any burrs in the ejector channel?
Did you try starting from the gas shut off with the gas block, then open it up 1/4 turn at a time until you get bolt lock with 1 round in the mag at a time?
Is the gas block sealed to the journal on the barrel tightly, or is there leakage evident?
It’s possible to have an ArmaLite MLGS length (longer) mixed with an incorrect AR-15 MLGS gas tube. They will generally run fine suppressed out-of-the gate, then start to malfunction with that configuration sometimes.
Is the gas tube flange worn down on one side from clipping the carrier key?
Is there any sign of gas leakage between the carrier key and the carrier?
Does your extractor have sharp corners on the lip?
Those need to be rounded if they’re sharp.
Any burrs in the ejector channel?
Did you try starting from the gas shut off with the gas block, then open it up 1/4 turn at a time until you get bolt lock with 1 round in the mag at a time?
Is the gas block sealed to the journal on the barrel tightly, or is there leakage evident?
If your barrel requires an Armalite AR-10 rifle length gas tube and you have an AR-15 rifle length gas tube installed it is very easy to see. The gas tube will not extend far enough into the upper receiver and into the gas key on the BCG. As a reference, the rifle on the bottom in this picture has a mismatched barrel and gas tube. The one on top is correct. Yours is a mid length though?
If all of your parts are mechanically sound...
and...
if I read the description of the problem correctly (failure to eject combined with early feed) I would attempt to resolve the issue by increasing BCG travel distance.
(Most phone cameras will shoot with a slow-motion function that is adequate to see ejection and BCG travel. At least the one phone I own will... I don't know why I concluded most phones will with a sample size of one.)
The simplest troubleshooting solution to do would be to increase the gas. The hope is that you can increase BCG travel to allow more time for ejection.
(My internet diagnosis says you have too much spring tension... Unless you need that spring tension for extraction issues, I bet you'll find results dropping the extra power spring and tuning the gas down.)
and...
if I read the description of the problem correctly (failure to eject combined with early feed) I would attempt to resolve the issue by increasing BCG travel distance.
(Most phone cameras will shoot with a slow-motion function that is adequate to see ejection and BCG travel. At least the one phone I own will... I don't know why I concluded most phones will with a sample size of one.)
The simplest troubleshooting solution to do would be to increase the gas. The hope is that you can increase BCG travel to allow more time for ejection.
(My internet diagnosis says you have too much spring tension... Unless you need that spring tension for extraction issues, I bet you'll find results dropping the extra power spring and tuning the gas down.)
I don't think the gas tube length is the issue. There is a ring where the gas key overlaps it. And it's not bent/clogged.
I've tried adjusting the gas, it goes from not cycling all the way to stove piping, no normal cycle.
The corners of the extractor are not sharp (atleast I don't think so) and no burrs in the extractor or ejector.
I've tried mixing and matching buffer weights with the 2 springs.
I haven't tried the camera slow motion, that's a good idea, but the fact that it holds open on one round makes me believe it goes back far enough, but its worth a look. The brass usually gets spun backward and lays in the chamber on those last shots if that may indicate something.
Thanks again guys!
I've tried adjusting the gas, it goes from not cycling all the way to stove piping, no normal cycle.
The corners of the extractor are not sharp (atleast I don't think so) and no burrs in the extractor or ejector.
I've tried mixing and matching buffer weights with the 2 springs.
I haven't tried the camera slow motion, that's a good idea, but the fact that it holds open on one round makes me believe it goes back far enough, but its worth a look. The brass usually gets spun backward and lays in the chamber on those last shots if that may indicate something.
Thanks again guys!
When you say "SR25 tube", what length is it?
Your gas tube flange is worn on one side, which means it has been clipping the carrier key until worn down, which means the BCG doesn’t get enough gas. That creates an ever narrower window for the system to run with, which could explain your symptoms.
Replace the gas tube and ensure it is installed with concentric alignment to the carrier key.
I’ve seen several rifles with this issue and cycling problems ensue every time.
You can see how the OD of the flange on the left side of the tube (top in your pic) is almost worn down to match the OD of the gas tube.
The buffer tube is a spikes sr-25/ar10 tube.
I'll try replacing the gas tube since I haven't done that yet. It is cycling far enough to lock, but its worth a shot. Thanks!
It’s getting more gas than it should if the port was drilled out to try to fix short-stroking.
When you install the gas tube, place the upper upside-down on the bench and strip your carrier of the bolt, cam pin, firing pin, FPRP.
Use the bolt carrier with key to test alignment with the gas tube as you move the block around with the tube already installed on the block.
You can find the most ideal mating between the gas tube and carrier key this way before resorting to bending.
Keeping the upper upside-down simulates the position the carrier will be in based on the magazine cartridge stack lifting up against the bottom of the BCG due to spring pressure.
This is one of the biggest things I see overlooked on both factory and DIY rifles.
When you install the gas tube, place the upper upside-down on the bench and strip your carrier of the bolt, cam pin, firing pin, FPRP.
Use the bolt carrier with key to test alignment with the gas tube as you move the block around with the tube already installed on the block.
You can find the most ideal mating between the gas tube and carrier key this way before resorting to bending.
Keeping the upper upside-down simulates the position the carrier will be in based on the magazine cartridge stack lifting up against the bottom of the BCG due to spring pressure.
This is one of the biggest things I see overlooked on both factory and DIY rifles.
Thanks for all of the suggestions guys. After replacing the gas tube and trying to tune, I was still having the same issues. I put in the azimuth double ejector bolt, ran like a champ! I went through 85 rounds without a single ejection issue both slow fire and rapid. I didn't try it with the standard spring, but it worked with the sprinco heavy, and if it ain't broke, don't fix it. Again, thanks for the suggestions and happy new year!
Before shit-canning the JP bolt, rip the shitty 1 pc ring they ship with off & replace with a new 3 pc ring set. You may find it works after that. Also may want to put a radius on the ejector pin/pins.
Unless I missed it have you messed with the extractor any? I've had a few 308 ar's give stovepipe issues and locking back on the last round but leaving the empty sitting on the mag. It was always an extractor tension or geometry issue.
In a few different rifles the double ejector bolts have been nothing but positive.
In a few different rifles the double ejector bolts have been nothing but positive.
When I clean it I'll check the pin diameter.
I originally changed the stock dpms extractor with a jp enhanced extractor. Then changed the entire bolt to a jp (new ejector as well). Thats 3 different extractors. But, I didn't do anything to modify them, so who knows. I'd like to think it cant be the same problem with 3 different parts, but its clearly possible. I am going to try to round the corners a little on the jp extractor and try it. It would be nice to have a back up bolt.
I originally changed the stock dpms extractor with a jp enhanced extractor. Then changed the entire bolt to a jp (new ejector as well). Thats 3 different extractors. But, I didn't do anything to modify them, so who knows. I'd like to think it cant be the same problem with 3 different parts, but its clearly possible. I am going to try to round the corners a little on the jp extractor and try it. It would be nice to have a back up bolt.
I had two 308 ARs at the same time for a while. One had a DPMS BCG and the other a LMT BCG with dual ejectors. I didn't have any stove pipes with the one with the DPMS BCG but ejection was pretty pathetic compared to the one with with the LMT in it. The LMT BCG on the other hand throws brass about 10 yards away.
Glad the new bolt resolved your issue, but a couple important things stand out in this pic.
1 - All the wear surfaces look bone dry and impacted with crud. You don't have to clean it every time you shoot it of course, but do put some oil on it. Oil the tip of the gas tube as well; that'll help prevent the wear you can see there. Are you one of those people who intentionally run their ARs without lube, or is this just a lack of maintenance?
2 - Those wear surfaces and the edges of the ejection port have a ton of wear on them. Probably mostly due to point #1 above; oiling your rifle makes it last longer. When you see bright aluminum instead of the black anodizing, you're wearing through the hard anodized layer into the soft aluminum underneath; this is very bad and your receiver is on a very limited life span at that point. Just based on the pic it looks like you've already worn through 90% of that receiver's life, presumably caused by running it dry if the picture is accurate.
It also looks like you've been prying open the BCG with a screwdriver through the ejection port? Be careful about creating burrs and chewing up the receiver that way.
