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Discussion Starter · #1 ·
Hey guys I have an LRB with a Arms #18 new style mount with Larue low rings. Occasionaly 1 out of a magazine worth of rounds wll jam between the Arms mount and bolt. Ive read that some individuals have their SAI M1a's ejector tuned by SAI, well mine isn't an SAI, anyone know how to "tune" the ejector so that it tosses the round at a more advantageous angle?
 

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I think it just involves shortening the spring a little bit at a time until the spent casings go where you want them. Don't quote me on that though.
 

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Is it doing what is shown in the attached photo?

If it is it can be fixed by tuning/changing the ejector spring and/or plunger. Some people have luck by trimming a coil or two at a time off the ejector plunger spring. However, if your existing spring is weak or too short already that will cause the problem too and trimming won't help. When I had this problem the spring was too short already and the ejector was not well machined. I bought a replacement from Numrich and they are very nicely machined but not USGI with a slightly longer spring than USGI standard of 2". Fixed my problem and they are cheap only about $3.00 each for the spring and plunger assembly.
 

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I have heard that this problem is due to Springfield's extractor, and that it can be fixed by replacing it with a GI extractor. Obviously that isn't the problem here, since yours is an LRB... but it could still be an out-of-spec extractor.

My Springfield cycles just fine with an ARMS #18. I have had it jam, but I found out that problem was mag-related, and does not happen when I use quality mags. What kind of mags are you using? Have you tried it with several different mags?
 

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When mine jammed with the Arms mount it was so bad i had to take the rings off, did it once every 20rounds or so.I replaced the ejector and extractor no change. The only thing that fixed mine was swapping out to a Sadlak Mount. If you can't get the ejector tuned try a different mount. Make sure to swap with USGI parts.
 

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Discussion Starter · #6 ·
The bolt is usgi trw with a usgi spring. Maybe ill swap springs first, what should the length be?
 
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