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Issue that I'm having with the Satern barreled rig. The ejection pattern is a consistent 1:00-2:00, it doesn't seem to care what spring or weight buffer is in it.
As set up right now:
18" bbl.
MLG
M16 carrier.
Wolff XTRA POWER spring.
Spikes T2 buffer.
It does feed and eject, weakly. I have used standard weight and standard spring, no real change. I am using the same load when testing.
Main issue that I have discovered is that the gas key is hitting the lower, at the top by the buffer, not real hard, but enough to leave a nice rectangular mark, and I don't want it hitting at all. I don't what size the gas port is in the barrel, but I guess it is too big.
Evidently I need an adjustable gas block or key, and I am asking for recommendations, any suggestions are appreciated.
This rifle hasn't been fired that much, I am just getting back to it after being tied down with other things, but I do want it to run right.
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Charlie,
What or sort of impact are we talking about? I ask because there's only 1/2" difference between where the BCG impact the lower and how far it has travel to catch the slide-locking-lever for bolt held open. If it is cosmetic like the anodising coming off then I wouldn't lose much sleep over it. It's not external so will not mar the finish. If it is serious denting then you are over-gassed.
When you say it ejects at 1:30 but weakly that is unusual because 1:30 is a sign it is over-gassed and too strong. Cases coming back towards the firer is weak. An adjustable gas will help tame the system.
The SLR Sentry series works for me.
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My 18" MLGS Satern Liberty / Stoner has an oversized gas hole. It's a pretty common recurring theme. An AGB solves the problem!
Let's go Brandon!
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Key hitting the lower is usually a buffer spring that is too short or receiver extension that is a bit too long, usually. Weak forward ejecting could be that the bolt is traveling past the back edge of the ejection port and the brass is tagging the back of port when cycled. The face of the bolt when the bcg is manually pulled all the way back should stop 1/8" to 1/4" in front of the back edge of the ejection port.
Easy fix for both, drop a couple of quarters in the bottom of the receiver ext. or mill/file/sand the front of the rec. ext.
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Lastrites, you have nailed it I think! The bcg is definitely traveling to far back. When I read your post I remembered seeing a little curved dent in one of the fired cases about 3/8" down from the bottom of the shoulder. The other cases in this test group have marks at the same location, but not as pronounced.
I have a little machine shop and some 1" Delrin round stock. I can make any size spacer needed.
The tube came from Brownells and I never thought to measure it before I installed it.
Thanks for adding to my knowledge of this platform, not to mention you may have saved me some money!
I don't know if I will get this done today, there is other work on the lathe, but I will let you know how it works out.
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Fixing the perceived over-travel on the BCG might not fix the late ejection. A stronger ejector spring will surely have those cases ejecting sooner.
The front of my bolt face comes to a stop level with the back edge of the ejection port however there appears to be no damage to the lower. The bolt locking lever engages when the bolt face is 1/4" in front of the back end of the ejection port so it needs to travel a bit further to clear it. I would be cautious to leave enough travel so that it can reliably lock back on on last round.
I would leave the buffer tube alone and get a stronger ejector spring and an AGB. The Adjustable Gas Block will allow you to manage how far the BCG travels.
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If Brownell's is selling out of spec Milspec parts under its house brand, I'm going to get truly dejected.
Let's go Brandon!
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07-03-2018, 02:28 PM
(This post was last modified: 07-03-2018, 02:53 PM by Mad Charlie.)
I don't know yet about the length of the tube, I will be finding out though.
I am leaning toward an adjustable key, in my configuration it may be much easier to adjust.
What do you folks think about the keys?
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07-03-2018, 02:53 PM
(This post was last modified: 07-03-2018, 09:15 PM by Mad Charlie.)
The receiver ext. tube is 7-3/4" long, measured on the inside.
https://www.ar15.com/forums/ar-15/Buffer...4-586906/?
It took a 3/4" spacer to make things happen like Lastrites described, a couple of quarters wouldn't have even been close.
I tested with two shots, got a 3:00 on first one and a 2:00 on second. bolt locked back. I did the test with a standard spring and T2 buffer.
Reading around the errornet is telling me that the inside measurement is supposed to be 7" but I am going to keep searching.
I dunno WHAT I have for a buffer tube. (yet)
Might just replace the buffer tube.
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07-03-2018, 10:30 PM
(This post was last modified: 07-03-2018, 10:47 PM by Mad Charlie.)
StoneHendge Wrote:If Brownell's is selling out of spec Milspec parts under its house brand, I'm going to get truly dejected.
StoneHendge, (and all) This a Ruger Elite complete lower, I did NOT get the tube from Brownell's. I had originally bought it for my Beowulf, and forgotten that I swapped it to this Grendel. My apologies. However, Ruger claims it as Mil-Spec. It is longer than any Mil-Spec lengths that I have found yet.
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From what you responded to me and the chart I found it is with out a doubt NOT milspec. Doesn't even fit the commercial specs that I can see.
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Popeye212, I noticed that also.
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By the way everybody, I hope all of you have a great 4th of July!
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I wonder if you got a buffer tube intended to be used on an AR-10 large frame. A Friend tried to install a commerical AR-15 buffer tube on a RRA LAR8 large frame and would not function. I read where certain large frame ARs used longer AR-10 specific buffer tubes. Wouldnt be the first time a product was sold with the wrong identification/packaging.
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When I call Ruger, I am going to give them the serial# and ask them. The lower seems to be a quality piece in most other aspects. I did replace that goofy trigger though.
I have never owned or even really looked at a large frame AR, but I don't think this lower is for a .308 or something. I guess it is possible that the tube is though.
Another angle to explore.
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DPMS pattern large frames (which is what the majority of do-it-yourselfers do) use standard AR 15 tubes with heavier buffers and springs, but there are a lot of proprietary large frames out there including RRA and POF (where I ultimately gave up on trying to get a rifle stock to work on my P308). I'm pretty sure the SR 7.62 is proprietary, but I was under the impression that Ruger contract out most of their AR assembly. If it was a large frame lower, it wouldn't fit into an AR 15 upper.
Let's go Brandon!
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Mad Charlie Wrote:StoneHendge, (and all) This a Ruger Elite complete lower, I did NOT get the tube from Brownell's. I had originally bought it for my Beowulf, and forgotten that I swapped it to this Grendel. My apologies. However, Ruger claims it as Mil-Spec. It is longer than any Mil-Spec lengths that I have found yet.
I have the Ruger AR-Lower Elite (#8516) and my buffer tube is mil-spec with the inside length just over 7 inches. There is a huge difference between this and an AR-10 lower.
You didn't like the "goofy" trigger?? That's a decent two-stage trigger, I really like mine.
If you somehow got the wrong buffer tube or a bad trigger Ruger will make it right. Call customer service, they'll fix it.
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Good morning Randy99CL. Thanks for the info on your buffer tube, much appreciated. As far as the trigger was concerned, I think something was wrong with it out of the box, the first stage was long, actually seemed longer than my M1A, and the second stage was very stiff and not very predictable at all. I didn't even put my scale on it, I just replaced it with a "Battle Arms Development Special Edition Frictionless Adjustable AR-15 Trigger" (gawd, that's kind of like those Englishmen that have four names) from Brownell's. Considering the limited amount of shots that I have on it on it, it is a very nice drop in trigger. I can say that it sure seems to be a high quality assembly.
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07-04-2018, 02:23 PM
(This post was last modified: 07-04-2018, 02:37 PM by montana.)
Klem Wrote:Fixing the perceived over-travel on the BCG might not fix the late ejection. A stronger ejector spring will surely have those cases ejecting sooner.
The front of my bolt face comes to a stop level with the back edge of the ejection port however there appears to be no damage to the lower. The bolt locking lever engages when the bolt face is 1/4" in front of the back end of the ejection port so it needs to travel a bit further to clear it. I would be cautious to leave enough travel so that it can reliably lock back on on last round.
I would leave the buffer tube alone and get a stronger ejector spring and an AGB. The Adjustable Gas Block will allow you to manage how far the BCG travels.
My thoughts exactly Klem. My favorite buffer tube with zero issues and consistent quality and carrier over travel has been the VLTOR https://www.brownells.com/rifle-parts/re...26608.aspx My troubles in the past have been under length buffer tubes of questionable quality, not over length.
When test firing my 300 BO, "I had just assembled" I had quite the surprise when the Geissele charging handle popped out and whacked me in the cheek. The carrier key groove in the Geissele charging handle is shorter than most which was a perfect indicator of the over gas problem. Like you, I use the SLR gas blocks which corrected the over gas, travel, recoil problem.
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Adjustable gas doesn't fix over travel of a bcg when dealing with out of spec parts. 7 3/4" inner length sounds more like an Armalite tube, your lucky with that amount of over travel that you didn't damage the receiver with the key banging it on the return stroke. A quick measurement revealed just shy of 7" on what I believe is a Psa tube.
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