r/LewisMachineTool

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Some of you may be familiar with my MARS-H and its feeding issues. Well, I took much of your advice:

- Reseating the barrel

- Testing different mags

- Send the whole rifle back

None of these solved my problem unfortunately. LMT even replaced the upper receiver to see if that would work. Now, some of you were on to something by mentioning the buffer system.

It turns out, the rifle was shipped with a rifle-length spring and “regular length” buffer. AR10s typically use shortened buffers, but an A5 buffer generally works with all “regular length” buffers. A shooting buddy of mine became deadset on fixing my problem and brought up something about a “shortened buffer” he had to install for his AR10 to work. One thing led to another and we tested a PSA carbine spring and shortened buffer in the MARS-H. You can see the results in the video.

I’ve ordered a Sprinco Blue and Kaw Valley Precision 5.6 oz buffer to confirm a parts swap will fix the rifle. I’m not exactly sure what to make of this. I appreciate LMT taking care of me, but it’s strange to me how this situation transpired. Prior to replacing my upper, LMT said they were conducting testing using commercial loads and didn’t experience any issues (at first). Then a week later they update me by simply replacing the upper.

It’s odd the gun never had issues on their end and then is unable to feed _any_ ammunition on my end. I don’t know to what extent things were tested - maybe the upper was put on a “testing lower”. After all, they reported testing on full-auto earlier in this process. Obviously, that’s not the type of lower I have.

I receive the replacement parts this week and should be able to provide follow-up testing results shortly. In the meantime, I’m posting this to share my findings with others. For the sake of everyone’s time I kept video length to a minimum - but going into it, the context is that I tried the same original loads from my first test, with the new upper. _Nothing_ cycled more than twice in a row. Then, I cycle two loads normally using the PSA buffer/spring combo. The hope is posting this will help others facing the same issue. Perhaps someone could shed some light or provide context on what’s going on technically as well?

Is fiocchi 168gr HPBT and black hills 168 OTM good SHTF rounds? Like performance on target. Both have been the best groups so far on my testing

Hi, I am getting a defender H and am somewhat lost on which combinations of Buffer Tube, Weight and Spring actually work.

Could someone make a list of parts which will work and are cheaper / better than the $140 complete LMT MWS Receiver Extension, Buffer Tube Kit. Also kind of impossible to find H3 buffers right now, so bonus points if it's something that's actually available.

Thank you!

Can’t wait to post sample this and get rowdy 😛

Anyone have one of these I could buy, or point me in a direction to find one? They're pretty illusive it appears.