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Discussion Starter · #1 ·
I'm getting close to finishing my M3HB build. For those of You that have done one of these I have a issue. Using Karma trigger, sear, and RSP. To install back plate and/ or remove I have to remove the trigger pin and pull trigger forward. The buffer hits it. This happens only with the M3 back plate. I have a M2 and it fits fine ?
Is this normal ? can I remove some material from the trigger ? or remove some from the buffer ? or leave as is an pull the trigger pin every time I tear it down?
Thanks for any help:help:
Greg
 

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Back plate

I have the exact same situation with the m3hb that I built. I did a little bit of searching on the topic, but didn't really come up with anything... It seemed to me that the trigger bar was hitting the trigger "finger" that sticks out of the buffer assembly. Being as that whole back plate trigger assembly is of after market construction, I figured the problem lay there. Not busting on the work on the spade grip assembly, it's top notch! Just figured the trigger finger was a little long... I'll be watching this thread to see what others have come up with! Regards, jon
 

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Pull the trigger bar pin ! M3 back plates have a much larger buffer plate in them ,so the trigger bar will not "pass" it as you slip them on .M2 backplates the buffer plate is small enough the the bar passes right along the right side with no issue .

The M3 back plate was never issued with a trigger except a solenoid type , the manual trigger is a modification done by a builder ,so the trigger finger hook can vary ,grind on it and you may screw up the ability of the trigger to correctly engage the trigger bar and trip the sear ! Better to do no modifications and just pull the pivot pin and reset it after you have the spades on !!

FWIW in IMHO :rolleyes:
 

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I had the same issue with my trigger assembly. My fix was to grind a bit off the trigger bar, and perhaps I got lucky, but it solved the issue. Rule of thumb: always modify the cheapest piece ;)

Then again, my "trigger pull" is heavy as heck, though that is not necessarily a bad thing. I never seem to notice unless I'm dry firing the gun ;)
 

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Then again, my "trigger pull" is heavy as heck, though that is not necessarily a bad thing. I never seem to notice unless I'm dry firing the gun ;)
I put an M2 backplate on my M3HB so I never seen the OPs issue.

Now, I traced heavy trigger pull to the sear spring. There's a thread on this started by myself. Long story short Ed at CWA had already solved the problem and had custom sear springs made for the M3 semi with KMP trigger. He GAVE me one.

Karl
 

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Discussion Starter · #6 ·
Pull the trigger bar pin ! M3 back plates have a much larger buffer plate in them ,so the trigger bar will not "pass" it as you slip them on .M2 backplates the buffer plate is small enough the the bar passes right along the right side with no issue .

The M3 back plate was never issued with a trigger except a solenoid type , the manual trigger is a modification done by a builder ,so the trigger finger hook can vary ,grind on it and you may screw up the ability of the trigger to correctly engage the trigger bar and trip the sear ! Better to do no modifications and just pull the pivot pin and reset it after you have the spades on !!

FWIW in IMHO :rolleyes:
That's what I've been doing, But it's kind of a pain in the a-- have to actually reach in and pull it forward. I was thinking that I could remove a little off the back of the trigger and all would be fine. I was wondering if any one else has tried this.

Karl whats the best way to get ahold of Ed, I need one of those springs. My trigger not too stiff ,but the spring I'm using is kind of deformed and I wearied that it won't last.
 

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Karl whats the best way to get ahold of Ed, I need one of those springs. My trigger not too stiff ,but the spring I'm using is kind of deformed and I wearied that it won't last.
Ed is the owner of Central Wisconsin Armory. call him there.
 
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