I just built an AR 6.5 Grendel, and having a little problem, the thing has an FTE every other round ! and the one that do eject only barely get out of the port. And the bolt hold dose not work. The bolt just pushes past it. I was thinking that the buffer spring is too strong ?
Am reloading the ammo 120gr SMK with 31.5gr of BL-C(2) w/Fed B/R Primer.
Any thoughts, and or suggestions would be appreciated.
How is it lubed?
I don't wanna oversimplify, but if you read what the ground-pounders do, you could get the impression the AR runs dry well.
Maybe, but in a very dirty environment, dry may be necessary.
Since you aren't in a desert windstorm, you wanna run that thing wet. And new, good and wet.
Bolt and BCG should be well lubricated.
Unless you have a carbine with a Rifle buffer and spring, I really doubt it is the spring.
And when you say the hold-open doesn't work, do you mean after last shot?
Or will it not hold open even if you pull the bolt all the way back on a empty mag?
Or even if you just hold the bolt stop with your finger?
Cause if it won't work manually, it has a part dimension discrepancy. If it only won't work on last shot, it's short cycling, which is why it is FTEing, too.
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Need lots more information:
Bolt from where?
Barrel from where?
Who built the upper? The lower?
Which mags are you using?
What buffer?
If its new, how wet are you running it? New equals tight, which means it needs LOTS of lubrication!
Is it a failure to eject, or is it short stroking? (How familiar with the AR are you?)
Failure to eject means that it won't toss the shell out of the rifle after extracting from the chamber. This is controlled by the ejector and ejector spring.
Short stroking means it might not be going far enough to the rear to actually get the shell ejected consistently, which is usually a gas problem, but very rarely could be a buffer/spring issue.
We sort of need to know your knowledge base to help, since you might have eliminated a bunch of stuff if you are familiar with the system and it would be useless for us to chime in with lots of things you have already investigated.
If you are an AR newbie, it changes the picture, in that there are some other things that might need to be explored.
Hope that helps!
No…not dry ! but will look at it again.
And it is a rifle, and it will stay open only if I have my thumb on the button with a lot of presser, let it go and slams shut !
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SCAMP62 Wrote:No…not dry ! but will look at it again.
And it is a rifle, and it will stay open only if I have my thumb on the button with a lot of presser, let it go and slams shut !
Somethings wrong with the build then. Either the parts aren't to spec, or not installed properly.
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FAILURE TO EJECT: This looks much the same as failure to extract, except that the fired case is removed from the chamber. The bolt will either jam the fired case back into the locking lugs on the barrel extension (crushing it), or pick up a round from the magazine and try to stuff both of them into the chamber at the same time (looks like a double-feed, except one of the cases is fired). There are a few possibilities as to the cause of this problem, and one is the ejector. For whatever reason, the ejector is weak or sticking and just not clearing the round out of the receiver. A good cleaning might solve the problem, or it may require replacing parts. Try the cleaning first. The other is that the extractor is letting go prematurely. A new extractor spring will usually solve this right away. Lastly, the bolt carrier might not be traveling back far enough, but if it is in fact picking up a new round from the magazine, this isn't the problem. If it isn't picking up a new round, you probably have a gas leak somewhere.
This is a kit from Model 1 Sales (I have a carbine from them, it runs flawless) Im not an expert on them, but have put together 5 of them. The Mags are C-Products,
The ejection seems erratic, out of 50 rounds, maybe 10 ejected with what I call normal force, the rest either just got out of the port, or jammed, most where stuck above the next round trying to get in the chamber !
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SCAMP62 Wrote:This is a kit from Model 1 Sales (I have a carbine from them, it runs flawless) I’m not an expert on them, but have put together 5 of them. The Mags are C-Products,
The ejection seems erratic, out of 50 rounds, maybe 10 ejected with what I call normal force, the rest either just got out of the port, or jammed, most where stuck above the next round trying to get in the chamber !
See above. Does that describe the situation?
To: bwaites
Yes the double feed is what it looks like ! will give a good cleaning
And thank you for the info !!
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No problem!
Good luck and let us know!
I think I figured it out gentlemen !
After swapping out a few parts, it became apparent that the bolt was not able to travel all the way back (why the bolt hold open would not work !) the bloody buffer is to long ! it’s ¼” longer then than any other buffer I compared it to ! and if I pulled the bolt back, the bolt face was ¼” forward of the bolt hold open lever ! So will give this a try this weekend, will let you know how it works out !!
I bet that a too long buffer could cause all kind of problems!!!!
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