Fit of a KAK LR308 upper to an Aero M5 Lower - good, bad, froggy? :)

[Tack14]

Have a chance to pick up an Aero M5 308 lower at  a good price and was thinking about maybe putting one together with a KAK LR308 upper for a build.

I am curious if anybody has ever put these particular two halves together and how well they fit.  I have KAK LPK's and LR308 "conversion"  parts (takedown and pivot pins, bolt catch, and extended mag release (extra threads length).

I'm thinking in particular of fit of the takedown and pivot pins, whether I should expect to need a dremel tool to "make it fit" (LOL), etc.

Thanks

Tack14

[Matt.Cross]

Just ignore all the folks here who recommend using matched uppers and lowers, and go for it. So what if some of those people are advising that because they learned it the hard way? Odds are you'll be the exception. It'll be fine, just do it already.... 

 

You're already ahead of the game by getting a great deal with your lower. Why waste that sensible good deal by following it with wasted time and bad decisions? 

Get a matching M5 upper and enjoy building a rifle without having to cobble mismatched parts together.

Or don't, either way let us know how it works out. If it's REALLY bad, we'd like pictures.

 

[Tack14]

HAHAHA!

Thank you Matt.  Funny AND good advice.  Love it!

Point taken. 

 

 

[Tack14]

Will get an Aero upper too.  

[98Z5V]

Damn common sense.  I wanted to see if this worked, and if it didn't, what problems came up.

Thanks, Matt. 

[Tack14]

lol.

Well, i can tell you the the same kind and ~amount of gap between upper/lower at the back is there as I've seen before.  Also, the KAK 308 front pivot pin is a bit short of fully reaching the driver's side.  It's probably not enough to be a problem, somewhere under 1/8".  But the KAK 308 front and rear pins seem to be a good diameter match.

They sat nicely together.  The tension set screw on the lower was backed out already and (with no BCG mind you) nothing held them apart (ie, no "dremelsmithing" looked to be needed).

It would ~probably~ work OK but since I can get an Aero upper to match I will do that instead.

[98Z5V]

34 minutes ago, Tack14 said:

lol.

Well, i can tell you the the same kind and ~amount of gap between upper/lower at the back is there as I've seen before.  Also, the KAK 308 front pivot pin is a bit short of fully reaching the driver's side.  It's probably not enough to be a problem, somewhere under 1/8".  But the KAK 308 front and rear pins seem to be a good diameter match.

They sat nicely together.  The tension set screw on the lower was backed out already and (with no BCG mind you) nothing held them apart (ie, no "dremelsmithing" looked to be needed).

It would ~probably~ work OK but since I can get an Aero upper to match I will do that instead.

Whoa!  Wait!  You already have the KAK upper?  Let's run this setup and see what happens, man - for real.  There's something to be learned here - be it good or bad, let's do this...  

This is the kind of stuff that make this place better.  If we don't have "real info" on something that some is asking - we'll find it out, and report back later...  

[Tack14]

I still have a couple KAK 308 uppers but my focus has shifted.  At some point I will, for the benefit of the forum users, try this out and report on it.

But for now I am going to focus on matched upper/lower endeavors.

Now I need to arrive at a good combo of DPMS Gen 1 rifle-length buffer system parts.  a specific brand/model of buffer tube to match up with a Heavy Buffers AR10 XH buffer.  Studying past threads info.

[Tack14]

Heavy Buffers AR10R-XH, that is....

[98Z5V]

Rifle receiver extensions are all the same, AR15 (A1 and A2), .308AR, whatever.  If made right, they're all 9 11/16" internal depth.  Combine that Slash buffer with an Armalite EA1095 spring, and you'll be set. 

Edited April 30, 2022 by 98Z5V

[Tack14]

Thanks 98Z5V.  Good to see the rifle buffer tube situation is not as complex.