View Full Version : 12:30-1:00 ejections. (Update: Possible loose gas block)?
Mauser KAR98K
04-10-16, 15:05
Started noticing this with M855 rounds (LC and Pri-Partisan). Having brass strike the front of the ejection port and noticing brass ejecting out at 12:30-1:00 position and sometimes dribbling out. Changed the action spring, running an H buffer. Had the gas rings replaced about 400 rounds ago (5K-6K rounds). Difference is I am running a BCM KMR 16" Mid over my LMT MRP (Lighter is better).
I'm also having random failures to lock back after the last round this is running all different kinds of ammo (steel and brass) and magpul and standag magazines. Running a Phase 5 BAD lever/bolt catch.
No malfunctions, but it concerns me.
Eurodriver
04-10-16, 15:07
A failure to lock back is a malfunction, homie.
Have you tried an H2 buffer?
Ok, so did you take the gas block off? Could be an alignment issue?
Mauser KAR98K
04-10-16, 16:35
A failure to lock back is a malfunction, homie.
Have you tried an H2 buffer?
First time I thought I may need one. (Didn't think that was part of the weird ejection).
Ok, so did you take the gas block off? Could be an alignment issue?
Nope. It's still together as it came from BCM.
Did you say you changed your buffer spring? I had some issues with a cheap o spring and wolf ammo. Put a colt spring in and no more problems. If youve got one lying around, give it a shot. An extra one that is, not neccessarily a colt.
Is the throat dented on the cases? Are they dented near the rim? If so, do you ever fail to chamber? Take 1 shot. Then, eject the newly chambered round to see if it has dents or anything near the back or underside
Eurodriver
04-10-16, 18:58
What about the extractor spring? That's probably where I'd start after thinking about it more...
What about the extractor spring? That's probably where I'd start after thinking about it more...
Yeah, with 5k down the pipe, that extractor spring is due for some PM.
Mauser KAR98K
04-10-16, 21:39
What about the extractor spring? That's probably where I'd start after thinking about it more...
Yeah, with 5k down the pipe, that extractor spring is due for some PM.
Need to ask my smitty, but I do believe he did replace the spring and placed a rubber O-Ring in it. Had this done with the SOPMOD upgrade kit and new rings at the 5K mark and noticed the rings were getting worn.
The action spring was about less than an 1/8" shorter than a replacement. But still having that weird ejection.
As for brass marks: I saw a brass spot mark where the M4 feed ramp and the receiver meet (not on the ramps themselves but the collar). Oddly enough, no dings or casing deformations. Weird.
Just took off the Phase 5 BAD lever. The magazine follower was going over the tab that pushes the bolt catch up. Replaced with a Mil-spec catch and problem. Just need to to shop for a good BAD lever that is stable...and in spec.
Need to ask my smitty, but I do believe he did replace the spring and placed a rubber O-Ring in it. Had this done with the SOPMOD upgrade kit and new rings at the 5K mark and noticed the rings were getting worn.
The action spring was about less than an 1/8" shorter than a replacement. But still having that weird ejection.
As for brass marks: I saw a brass spot mark where the M4 feed ramp and the receiver meet (not on the ramps themselves but the collar). Oddly enough, no dings or casing deformations. Weird.
Just took off the Phase 5 BAD lever. The magazine follower was going over the tab that pushes the bolt catch up. Replaced with a Mil-spec catch and problem. Just need to to shop for a good BAD lever that is stable...and in spec.
So, removing the BAD lever fixed your issue?
So, removing the BAD lever fixed your issue?
if that's the case, I am reconsidering if I want one or not..
if that's the case, I am reconsidering if I want one or not..
Just remember to avoid them on Duty guns.
I have never used one, but based on design, anything extra that operates in the trigger guard is alarming to me. Not to mention, in a stressful situation, no one wants their bolt to be locked open because while shooting something hit that lever.
For competition, I have heard it does wonders for speed loading, but definitely avoidable for hard/life-depends-on-it use.
ETA: I should clarify, I am not bashing it in anyway, nor questioning why someone would use one.
Just remember to avoid them on Duty guns.
I have never used one, but based on design, anything extra that operates in the trigger guard is alarming to me. Not to mention, in a stressful situation, no one wants their bolt to be locked open because while shooting something hit that lever.
For competition, I have heard it does wonders for speed loading, but definitely avoidable for hard/life-depends-on-it use.
ETA: I should clarify, I am not bashing it in anyway, nor questioning why someone would use one.
Its theory based anyhow. AK guys have figured out how to speedload and such. Its an extra way to manipulate the weapon. Id still like to have one, but I appreciate the bit of advice on a duty gun. One thing to have a fun gun.
Mauser KAR98K
04-11-16, 18:50
So, removing the BAD lever fixed your issue?
if that's the case, I am reconsidering if I want one or not..
NOOOOO!!! What it solved was the failure to hold the bolt open after the last round.
The Phase 5 BAD lever I have has the tab that allows the magazine to push up the bolt catch. The tab was getting missed as it wasn't long enough to be engaged. I'm looking for a replacement. I love the BAD lever for the ease of doing a double feed clearing, and it does speed up the reload.
NOOOOO!!! What it solved was the failure to hold the bolt open after the last round.
The Phase 5 BAD lever I have has the tab that allows the magazine to push up the bolt catch. The tab was getting missed as it wasn't long enough to be engaged. I'm looking for a replacement. I love the BAD lever for the ease of doing a double feed clearing, and it does speed up the reload.
I've played with the Tactical Link BAL and Magpul BAD. I like the idea, but ended up ditching them in favor of an enhanced bolt catch from Seekins or Forward Controls. The Tactical Link in particular caused periodic failures to hold open. It's essentially the same as a Magpul BAD, but it's a bigger, longer, heavier part and I suspect the extra weight was the cause of the problem. I took it off and the malfunctions stopped. I never had any real issues with the Magpul BAD, but couldn't warm up to it either. If you want to use one of these types of levers it's the one I would recommend though because it's the least amount of additional weight stuck on your bolt catch.
I would look at the ejector spring as well. My SR15 spitting brass out in weird directions and only few inches from the gun. Changed out the ejector spring and that solved the problem.
I would look at the ejector spring as well. My SR15 spitting brass out in weird directions and only few inches from the gun. Changed out the ejector spring and that solved the problem.
I'd second this. In fact, I cut the ejector spring down on my Service Rifle AR intentionally to achieve just this result. Keeps the rifle from tossing brass all over the firing line. Guys shooting next to me appreciate not having hot brass thrown all over them and it all lands in a nice neat pile.
You could also have a build-up of brass bits interfering with operation of the ejector - you wouldn't think that stuff would get down the hole past the ejector, but it does.
Mauser KAR98K
04-11-16, 21:17
I'd second this. In fact, I cut the ejector spring down on my Service Rifle AR intentionally to achieve just this result. Keeps the rifle from tossing brass all over the firing line. Guys shooting next to me appreciate not having hot brass thrown all over them and it all lands in a nice neat pile.
You could also have a build-up of brass bits interfering with operation of the ejector - you wouldn't think that stuff would get down the hole past the ejector, but it does.
What's the best way to remove it for an inspection? And where would I find replacement (quality) parts?
What's the best way to remove it for an inspection? And where would I find replacement (quality) parts?
First step, Just lubricate the ejector and work it in with a spent case for leverage.
More likely sticky than worn out.
What's the best way to remove it for an inspection? And where would I find replacement (quality) parts?
BCM sells a bolt upgrade kit
titsonritz
04-12-16, 11:18
What's the best way to remove it for an inspection? And where would I find replacement (quality) parts?
You need to depress the ejector to the bolt face, this will allow you to drift the pin and remove the ejector and ejector spring. Here are tools that help.
https://www.youtube.com/watch?v=GeTa1tRHFUc
(http://www.brownells.com/search/index.htm?k=ejector+tools&ksubmit=y)
BCM sells a bolt upgrade kit
That BCM kit has nothing to do with the ejector, it is for extractor and gas ring replacement. This kit from Specialized Armament (http://www.specializedarmament.com/products/Bolt_Assembly_Rebuild_Kit-1144-292.html) contains all the parts for a full ejector/extractor rebuild, the individual parts can be found there as well as Brownells.
ExplorinInTheWoods
04-12-16, 11:43
I was having problems similiar with a spikes build with a NiB BCG. I was having double feeds if occasional rounds would stick to the bolt and my rounds would eject at 1 o'clock. I emailed spikes and they sent me a new bolt and since then about a 1K rounds no problems and 4 o'clock ejection now.
Mauser KAR98K
04-12-16, 19:28
Upon further inspection of the upper, I might have discovered a loose gas block. Need opions before I email BCM.
https://farm2.staticflickr.com/1646/26398258215_fdd798e309_b.jpg
https://farm2.staticflickr.com/1540/25793433224_5394378371_b.jpg
https://farm2.staticflickr.com/1491/26125417880_9a25a6c281_b.jpg
Brass fired. M855
https://farm2.staticflickr.com/1635/26332077251_18bae2e76a_b.jpg
Brass marks near ejection port.
https://farm2.staticflickr.com/1631/25795520473_c9bc1f8622_b.jpg
I win! Pull the rail, and see if you can tighten the set screws back. Maybe even a little blue loctite on the threads if youre sure that its aligned. Barrel may be dimpled or have marks under the set screws. At 5k rounds, something is bound to work loose.
titsonritz
04-12-16, 19:51
I win! Pull the rail, and see if you can tighten the set screws back. Maybe even a little blue loctite on the threads if youre sure that its aligned. Barrel may be dimpled or have marks under the set screws. At 5k rounds, something is bound to work loose.
Red Loctite for gas block screws.
Yeah. That stuff is better haha
Mauser KAR98K
04-12-16, 20:24
I win! Pull the rail, and see if you can tighten the set screws back. Maybe even a little blue loctite on the threads if youre sure that its aligned. Barrel may be dimpled or have marks under the set screws. At 5k rounds, something is bound to work loose.
The BCG has over 5K rounds. The Upper has maybe 500 rounds.
Should I call BCM and have them do it? Yes, I have the tools for a KMR.
The BCG has over 5K rounds. The Upper has maybe 500 rounds.
Should I call BCM and have them do it? Yes, I have the tools for a KMR.
Yeah id call them idk how they work but they may set up up somewhere to have it fixed locally.
What do you see in those pictures that makes you think the gas block is loose?
Sent from my SCH-I605 using Tapatalk
jackblack73
04-12-16, 23:53
What do you see in those pictures that makes you think the gas block is loose?
Sent from my SCH-I605 using Tapatalk
I was wondering the same thing. If it's the gap, that's for the handguard cap.
titsonritz
04-13-16, 00:18
The BCG has over 5K rounds. The Upper has maybe 500 rounds.
Should I call BCM and have them do it? Yes, I have the tools for a KMR.
If you got it new from them, have another upper or other ARs and don't mind the wait I'd send it back. If not I'd just do the work myself and be done with it.
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