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Case not ejecting on a fired round - Stugotz - 11-01-2021
I have begun working up loads for hogs with my AR15 6.5 Grendel build. The problem I have been having is after I fire a round, the case fails to eject. I have an adj. gas block which is basically wide open at this point. Barrel is a 22" with a rifle length gas system. I began working up reloads using 26grs of Alliant Power Pro Varmint using 123gr Hornady SST's. My heaviest charge is 28grs. For each 5 shot string, I inspected each case for signs of hi pressure. (Saw no indications with excessive pressure).
The issue I have is not 1 single case was ejected after the shot. In many cases, I had to really pull hard on the charge handle in order open the chamber and remove the spent brass. I finally had a friend watch the BCG while I took a shot down range to see if the BCG was moving at all. He said after watching me take 8 or so shots, the BCG did not move at all or moved back very little. (My guess is it may be related to head space issues...)
I have built 15+ AR's mostly .223 with 1 rifle chambered for for .204 Ruger, and 2 AR10's (1 chambered in .308 and the other, 6.5 Creedmoor) and everyone of them ran flawlessly.
Any ideas on a course of action to figure this out?
Case not ejecting on a fired round - mdram - 11-01-2021
make sure the gas block is aligned with properly would be my first step
Case not ejecting on a fired round - Dt219 - 11-01-2021
Or a gas leak would be next
Case not ejecting on a fired round - Stugotz - 11-01-2021
I just pulled the handguard and gas block and noticed the port on the gas block did not perfectly align up with the gas port on the barrel. I believe that should solve my problem and will let you know after I have a chance to go to the range and shoot it later this week. Thx for the reply's!
Case not ejecting on a fired round - Stugotz - 11-04-2021
I got a chance to sneak away from work this afternoon and chrono some loads for my hog hunt down in Tx this January. On a positive note, all of my loads grouped 1 MOA or less. The BCG is still not coming out of battery enough to eject the spent shell casing. (Adj gas block cranked wide open). I asked a fellow shooter to video the action while I took a shot down range and just watched the vid. As I stated, the action is opening. I went through the vid frame by frame and estimate the action opens approx. 1.35-1.4". I live about 40 miles south of JP Enterprises and plan on making a trip up to their offices (Silent Captured Spring in tow) and asking them if they can break it down reducing the weight of it and seeing if that will make a difference...
Case not ejecting on a fired round - sundowner - 11-04-2021
All I can think of is the the whole in the barrel may be to small to let enough gas through .
Case not ejecting on a fired round - justinspicher - 11-04-2021
What size buffer and spring are you using? Are the lugs tight on your BCG? Have you checked your gas rings on the bolt?
I had this issue earlier this year with a build and all three were an issue.
Case not ejecting on a fired round - montana - 11-04-2021
It can be many reasons why your rifle is failing to eject. First thing is to check your chamber to make sure it will pass a go- no go gauge. A tight chamber can cause excessive pressures resulting in function issues. More than likely it is a gas issue. The best way to check the gas block- barrel port alignment is with a bore scope and a lighted gas tube. Check the gas block barrel journal fit for excessive gas leakage. Then move back from there by checking the gas block- gas tube interface and check for excessive gas leakage, check the gas tube for any cracks or leaks, check the gas key-gas tube interface. Using a pin gauge the gas key I.D. should be .180 to.182. A Mark Brown custom gas tube gauge checks the button on the end of the gas tube for excessive wear, that can cause excessive gas leakage. Most gas leaks occur between the gas key and the bolt carrier. The gas key screws may look fine but can have a broken screw or be loose. The gas key screws should be tightened to 55 to 58 inch pounds. Mill spec requires a gas sealant between the gas key and carrier, but many companies do not do this. The inside of the bolt carrier has three bores that may or may not be gas efficient, especially between the bolt tail and bolt tail bore. Do the gas ring test on your bolt carrier group. If all else fails, then it may be necessary to open the barrel's gas port. One area I always check, "especially with the Grendel bolt" is the extractor. If the extractor has the rubber O-ring, I will remove the O-ring if the extractor spring is strong and the extractor spring has the black plastic insert, see if this helps. Too much extractor force can cause function issues.. If you have a JP SCS with tungsten weights, it is very easy to take apart and change weights. JP has a video on how to do this..There can be other problem areas such as barrel clocking in the upper, buffer tube alignment and depth, fire control group problems, etc. Good luck...
Case not ejecting on a fired round - Stugotz - 11-04-2021
JP Silent capture spring. (Same setup that I have used on 5 other AR15 builds). Lugs are tight on the BCG. Broke down the BCG and the rinks function/appear as new.
I spent over an hour with Dustin (with JP Enterprises) ad he systematically walked through potential problems. I've decided to tap a friend who owns a machine shop and open up the gas port on the barrel a few thousands and see if that solves my problem. (I'm using an adj. gas block on the build).
I have to say Dustin spent way more time with me on the phone that I deserved helping me diagnose my problem! GREAT CUSTOMER SERVICE!!!
Case not ejecting on a fired round - montana - 11-04-2021
Stugotz Wrote:JP Silent capture spring. (Same setup that I have used on 5 other AR15 builds). Lugs are tight on the BCG. Broke down the BCG and the rinks function/appear as new.
I spent over an hour with Dustin (with JP Enterprises) ad he systematically walked through potential problems. I've decided to tap a friend who owns a machine shop and open up the gas port on the barrel a few thousands and see if that solves my problem. (I'm using an adj. gas block on the build).
I have to say Dustin spent way more time with me on the phone that I deserved helping me diagnose my problem! GREAT CUSTOMER SERVICE!!!
I have a Faxon barrel that needed the port opened. It is important to incrementally open the port and try the rifle ammunition combination you are planning to use. Be careful the drill bit does not go too far and damage the bore opposite the port hole. An adj gas block will only restrict the gas port pressure and will work if a port has excessive pressure, but it is best to find the sweet spot. A 22" barrel should be a soft shooter to begin with, so be very careful opening the port. Good to hear JP was so helpful, I also use the JP SCS in most of my builds. Good luck and let us know how it works out..
Case not ejecting on a fired round - Stugotz - 11-04-2021
montana Wrote:It can be many reasons why your rifle is failing to eject. First thing is to check your chamber to make sure it will pass a go- no go gauge. A tight chamber can cause excessive pressures resulting in function issues. More than likely it is a gas issue. The best way to check the gas block- barrel port alignment is with a bore scope and a lighted gas tube. Check the gas block barrel journal fit for excessive gas leakage. Then move back from there by checking the gas block- gas tube interface and check for excessive gas leakage, check the gas tube for any cracks or leaks, check the gas key-gas tube interface. Using a pin gauge the gas key I.D. should be .180 to.182. A Mark Brown custom gas tube gauge checks the button on the end of the gas tube for excessive wear, that can cause excessive gas leakage. Most gas leaks occur between the gas key and the bolt carrier. The gas key screws may look fine but can have a broken screw or be loose. The gas key screws should be tightened to 55 to 58 inch pounds. Mill spec requires a gas sealant between the gas key and carrier, but many companies do not do this. The inside of the bolt carrier has three bores that may or may not be gas efficient, especially between the bolt tail and bolt tail bore. Do the gas ring test on your bolt carrier group. If all else fails, then it may be necessary to open the barrel's gas port. One area I always check, "especially with the Grendel bolt" is the extractor. If the extractor has the rubber O-ring, I will remove the O-ring if the extractor spring is strong and the extractor spring has the black plastic insert, see if this helps. Too much extractor force can cause function issues.. If you have a JP SCS with tungsten weights, it is very easy to take apart and change weights. JP has a video on how to do this..There can be other problem areas such as barrel clocking in the upper, buffer tube alignment and depth, fire control group problems, etc. Good luck...
Hey Mt! I looked for signs of gas leaks at the point where the gas block attaches to the barrel, and where the gas tube is inserted into the gas block (no cracks/leaks and I do have a rubber O-ring) as well as the chamber where the gas exhausts into the port of the BCG while attempting to cycle it. The only signs of spent powder residue is in the chamber in addition to the coating of residue in/on the BCG. If opening the gas port on the barrel fails to solve the problem, I will look at the Grendel bolt extractor. Thanks again Mt!
Case not ejecting on a fired round - montana - 11-05-2021
Stugotz Wrote:Hey Mt! I looked for signs of gas leaks at the point where the gas block attaches to the barrel, and where the gas tube is inserted into the gas block (no cracks/leaks and I do have a rubber O-ring) as well as the chamber where the gas exhausts into the port of the BCG while attempting to cycle it. The only signs of spent powder residue is in the chamber in addition to the coating of residue in/on the BCG. If opening the gas port on the barrel fails to solve the problem, I will look at the Grendel bolt extractor. Thanks again Mt!
I would try removing the extractor O-ring before opening the gas port. The extractor is very easy to remove and reinstall for function testing. I would eliminate any possible causes for short stroking before I altered the barrel port.I failed to ask if you called the barrel manufacturer to see what gas port size they recommend for your barrel. Always start with the manufacturer to see if they will warranty or give helpful advice. Take your time and watch the videos from then School of the American rifle.https://www.youtube.com/c/InstructorChad/videos There is a lot of bad information being put out about the AR Stoner system, but Chad has been instructing people in the industry for quite awhile and has a better understanding about Stoner's system than anyone I have encountered so far... Enjoy the process..https://www.arbuildjunkie.com/ar-15-parts-quality-control-a-school-of-the-american-rifle-update-qa/ https://www.arbuildjunkie.com/common-ar-15-myths-school-of-the-american-rifle/ https://www.arbuildjunkie.com/ar-15-gas-system-issues/ https://www.brownells.com/aspx/learn/learndetail.aspx?lid=11004
Case not ejecting on a fired round - Stugotz - 11-05-2021
Mt, I will throttle back and follow your advice. Plenty of time between now and when I leave for my hog hunt down in Tx.
Case not ejecting on a fired round - Stugotz - 11-05-2021
I believe I found the root problem. I measured the distance between the edge of where the hole was bored through the barrel allowing the gas to vent into the gas block and to port in the gas block. If I seat the gas block against the the shoulder of where the gas block seats against the barrel the gas block port extends beyond the barrel port by approx. 1mm. (Please see the attached pix.) I tightened down the gas block 1mm prior to where it engages the shoulder of the barrel and it centers over the port on the barrel perfectly. So who is at fault? The gas block manufacturer for incorrectly drilling the port in the block, or the barrel manufactured for incorrectly drilling the gas port in the barrel 1mm further down the barrel (closer to the muzzle of the barrel?!?[ATTACH=CONFIG]18346[/ATTACH]
Case not ejecting on a fired round - mdram - 11-05-2021
i beleive this space is normal
read this
https://www.brownells.com/aspx/learn/learndetail.aspx?lid=16737
Case not ejecting on a fired round - montana - 11-05-2021
Stugotz Wrote:I believe I found the root problem. I measured the distance between the edge of where the hole was bored through the barrel allowing the gas to vent into the gas block and to port in the gas block. If I seat the gas block against the the shoulder of where the gas block seats against the barrel the gas block port extends beyond the barrel port by approx. 1mm. (Please see the attached pix.) I tightened down the gas block 1mm prior to where it engages the shoulder of the barrel and it centers over the port on the barrel perfectly. So who is at fault? The gas block manufacturer for incorrectly drilling the port in the block, or the barrel manufactured for incorrectly drilling the gas port in the barrel 1mm further down the barrel (closer to the muzzle of the barrel?!?[ATTACH=CONFIG]18346[/ATTACH]
You are at fault if the gas ports don't line up
Not all gas blocks sit flush to the barrel journal shoulder. I take a measurement from the edge of the gas block to the port center and take a measurement from the shoulder of the barrel journal to the barrel port center to get perfect alignment. Then I verify my alignment with a bore scope and gas tube light. If you have a bottom set screw type gas block, the SLR barrel dimpling jig does a good job lining the ports for proper dimpling..
Case not ejecting on a fired round - montana - 11-05-2021
There are some really good bore scopes that are quite reasonable for most needs.https://www.amazon.com/Teslong-Borescope-Side-View-Semi-Rigid-Smartphone/dp/B07TTQF24F
This is the light I use that has worked the best.
https://xtremeeffects.com/gas-system-illuminator?fbclid=IwAR141M4wHverwzJNT2OYDAGAMLfRtYwf7La-h7zgR6XN1JGXprt9Rgk1Dz4
I have this cheaper one that worked OK and is better than nothing if cost is an issue. https://www.amazon.com/dp/B096Y93TPX but I would recommend the other..
Case not ejecting on a fired round - Stugotz - 11-05-2021
I already own a Teslong bore scope and went halves with a friend on a Lyman. (The Teslong is the better of the 2). I confirmed with a friend regarding the issues of the offset that is referenced in the Brownells ling post by mdram. Quite aware with not having measured to make sure the 2 ports did not line up that I am ultimately at fault, I just have never run into this issue before. In my personal collection I have built 9 AR uppers and have built/assisted a few of my friends in another 12 or so builds. Totally un-expected find reguarding the repositioning of the gas block on the barrel... Live and Learn!
I will be out shooting this rifle tomorrow verifying this solved the problem.
Case not ejecting on a fired round - Stugotz - 11-05-2021
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Case not ejecting on a fired round - Stugotz - 11-05-2021
mdram Wrote:i beleive this space is normal
read this
https://www.brownells.com/aspx/learn/learndetail.aspx?lid=16737
It sure would have been nice if Criterion had pointed out this fact in the paperwork I received with the barrel... The good news is this barrel is crazy accurate with all of the loads I have worked up to day.