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01-28-2012, 08:56 PM
(This post was last modified: 01-28-2012, 09:03 PM by BjornF16.)
Finding dents on my ejected case main body (my Satern Spartan home build, see first picture). I don't get this dent on my AA built Entry upper. The middle picture shows lack of denting on neck with my home build, while the third picture is the dented neck from AA Entry.
What would cause the dented main body? Will this affect reloading safety?
I am running a PRI adjustable gas block and have tuned the gas return down significantly to avoid the dented neck and increase velocity. The action cycles just fine (locks open on last round with no failure to eject/feed). I started at fully closed, then 1.5 turns open. From there I closed it another half turn (now 1 turn from fully closed). Dents occur at both settings.
Is this possibly not enough gas to cycle carrier in time for case to clear the ejection port before being slammed to the side? The dented cases end up at the 2-3 o'clock position at half the distance of the fully gassed AA Entry (Entry brass ends up at the 4 o'clock position).
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I've had the body ding on both my Grendels, but never that pronounced. I'm sure one of our resident technical guys can shed more light on causes than I.
subscribing, some of my cases are dented also like that, not all though..
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Update...investigating further it appears the dent is perfectly aligned with the sharp edge on the ejector port deflector (where it angles backward). So instead of flinging off violently (at full open gas) during bolt retraction and smashing the neck mid-way down the deflector, it appears the body is hitting the deflector edge during ejection.
Maybe someone can explain this...and does it impact reloading?
so would putting velcro on it cure that?
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What stokerj said! It's not too tough, but go very slowly and take off only a tiny bit at a time.
You seek escape from pain. We seek the achievement of happiness. You exist for the sake of avoiding punishment. We exist for the sake of earning rewards. Threats will not make us function; fear is not our incentive. It is not death that we wish to avoid, but life that we wish to live. - John Galt
That is what solved my issue some months ago.
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01-29-2012, 03:07 PM
(This post was last modified: 01-29-2012, 03:14 PM by rasp65.)
I agree with stokesrj I used the info from the link on my Grendel and a 223 AR. I made my own V-block with a piece of 2x4 and a router. Because the ejector roll pin is offset it is really hard to remove the pin without a v-block, also I bent 2 punches without it. I only pushed the roll pin out until the ejector was free because starting the offset roll pin is a PITA. You should have a spare available before you start doing this just in case. Other benefits to this are not having those deep gouges in the neck that can be seen in the 1st pic under your index finger and the brass not going as far. One other thing that may be causing this is too light a buffer but either way you will benefit from modifying the ejector spring.
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Performed the modification described in the link above...shot 5 rounds with 4 failure to extract.
Could it be possible that I have undergassed the system with my adjustable gas block (it is less than 1 turn from fully closed)? This gas setting worked fine prior to the modification.
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Bjorn The modification of the ejector shouldn't effect the extractor.
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Sorry, let me be more precise. The case was extracted from the chamber in all cases but was not ejected properly.
Four shots resulted in spent case remaining loosely just above magazine. This of course interfered with insertion of next cartridge (this occurred twice). I then shot with empty magazine inserted three times. Twice the result was loose cartridge sitting on top of magazine with bolt locked back. Once the case was properly ejected.
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Bjorn How much of the spring did you remove?
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Might have trimmed the ejector spring too short.
Drifter
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I trimmed enough spring to leave it protruding just under 1/16" beyond face (I left a little more than the instructions said). I'll swap out the spring after trimming the new one by half as much.
I did go back to the range after opening up the gas block more...no difference. I gather there is a difference between 5.56 and 6.5 when it comes to ejector force?...:o
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Bjorn I have done it to both 6.5 and 5.56 bolts in both cases I left it longer than what the instructions said. I think that I removed 2 or 3 coils depending how you look at the spring. I wanted to make sure I didn't take too much off especially since the spring is kind of hard to hold securely,as you probably found out.
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Try an extractor up-grade, such as the D-fender, to eliminate extraction problems, my AA upper was a nightmare first time at the range-same as yours, bjorn = empty brass on top of fresh round in mag., then zero extraction. I felt the need to send the upper back. A new D-fender cured that. As far as the ejector spring- cut 1.5- 2 coils-then leave it alone.
