08 July 2015

Assembly Complete

I posted a month ago Some Assembly Required.  Tonight we unveil the finished product:

I like the contrasting colors and very happy with the finished product.  As a review, this is an FMK lower acquired via a FoNRA auction, with a DPMS lower parts kit and adjustable stock.  Topped with a Bushmaster upper in 5.56.  The sight is a Sightmark dual red dot with laser picked up at yet another FoNRA dinner.

And the assembly was almost trivial.  The parts are sized to only fit where they go.  I started by watching Larry Potterfield of Midway USA build a lower.  Thanks Larry, the video helped a lot!

But there are a coupla gotchas:
Mistake #1, I skipped step one (Clean out all the holes).  The holes looked clean so I didn't sweat it.  Unfortunately the buffer retainer pin snagged in it's recess.  But further investigation showed the hole was drilled undersized.  The hole fit a 1/4" drill perfectly, but the retainer pin measured 0.252" dia.  Hmmm methinks interference fit is not a good thing for a pin that's supposed the slide up and down.  Meanwhile a 17/64 drill bit  (.2656")  was loose in the same hole on the "other" FMK lower (another story from another FoNRA dinner).

I stuck with the trigger included with the LPK rather than a fancypants lightweight trigger.  Mebbe next time.

I'll probably add a BUIS because holo-sights are notorious for turning themselves on a burning the battteries.

Special tools:
Larry goes on a while about all the special tools required to build but I found most were not needed.  The lower armorer's block takes the place of the "third hand" by holding the lower fixed.  Also the roll pin starter punch set made the roll pin easy.  But the foreward retainer pin & spring was very easy to install without special tools.

Lessons learned:
1.  Do the assembly in an "aquarium" or "tent", even drape a towel to catch the small parts and springs that take flight during assembly.  

2.  Order extra parts.  Somewhere here in SandCastle HQ is a buffer retainer pin and spring.  They launched while trying to install the aft take down pin retainer spring.  Next Midway order included not one but two retainers & spring sets (~$2-3 for each set - cheap compared to the time to either find them or acquire a new set).  Then the aft retainer spring took flight while compressing.  Fortunately I had a pretty good idea of the trajectory and was able to find it.  I got lucky.  Next time I'll get extras of both.

Heh.. Midway et al ought to offer a "launched parts kit"  That is a collection of the springs and parts that are likely to get "launched" and lost during assembly,  Probably only cost $5-8 dollars.   I'd  highly recommend!

The "other" FMK lower from the "other" FoNRA dinner is black.  The SCSon advocates wood furniture.  And I think he's right.  I think the dark walnut will go well with the black upper & lower.  Question is, what upper do you pair with a wood furniture lower?  To me, wood implies hunting rather than tactical and to me hunting means distance.  I'm thinking maybe a 20" flat top upper, medium power scope and fancypants trigger.  What do you think?

FTC disclaimer: No compensation has been provided or promised in any form for this post.  All parts mentioned were purchased at retail or acquired as described in the post.  I'm a longtime happy Midway customer and greatly respect the support Midway & the Potterfields give back to the shooting sports.  I *think* the SCSon's SCTP team benefits but that's as close as it gets.

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