20" A4's ?'s Colt VS FN vs BCM, others

[CAVDOC]

Looking to put a 20" A4 like I toted on deployments to the stable. My research suggests the Colt and FN are pretty similar except the FN comes with a KAC rail and matech versus Colt having the carry handle. The MSRP on the Colt is easier to swallow, considering a KAC RAS can be found for under $200. Am I missing anything.The rifle I was issued was an FN , but certainly had my share of Colt in my 25 year career as well Help me decide!

[Falar]

Looking to put a 20" A4 like I toted on deployments to the stable. My research suggests the Colt and FN are pretty similar except the FN comes with a KAC rail and matech versus Colt having the carry handle. The MSRP on the Colt is easier to swallow, considering a KAC RAS can be found for under $200. Am I missing anything.The rifle I was issued was an FN , but certainly had my share of Colt in my 25 year career as well Help me decide!

Colt AR15A4+KAC M5 RAS is the route I'd go.

In a strange twist since carbines are so much more desireable though the 6920 and AR15A4 share an MSRP (999) BUT because much fewer AR15A4s are made it seems they are always listed well over vs 6920s being well under.

I get the 20" bug every now and then as well but then I think "what's the point" since it still won't have a massively increased effective range so 20" for me is the realm of .308 ARs. Plus, the only time I ever handled a musket was in basic training as even way back in '01 when I got to the 82nd M4s had been standard issue for quite some time.

Though a Colt M16A4 and M4 clone would be cool to have in the collection, I can't deny. The latter would need a tax stamp though.

[Eurodriver]

I have a neat A4.

I used a Colt upper on a BCM barrel (swapped the upper out to get rid of the laser marking) and a PSA OIF lower.

Doing it over I would have bought a Colt. Much simpler.

[CAVDOC]

My theory regarding the newFN or Colt 20" A4 is I can not only have a rifle similar to my deployment rifle, but also use it for CMP service rifle matches ( not optimal I know but I am not really competitive any more) and have the option of optics down the road. When I look at the size and weight difference between the 16 and 20 it really doesn't make that much difference

[556Cliff]

Colt uses 7075 aluminum for their rifle receiver extensions. FN carbine and rifle receiver extensions are unknown and BCM rifle receiver extensions are also unknown.

So, Colt wins here.

[Falar]

Colt uses 7075 aluminum for their rifle receiver extensions. FN is unknown but likely uses 6061 and BCM uses 6061.

So, Colt wins here.

I have an FN 15 carbine and the manual states 4140 barrel steel as well. I know that it is just a blanket manual for many models and it may even vary so no telling what the "Military Collector series" barrel steel is but it at least puts it in doubt. Everything else seems pretty chart-tastic though: taper pins at the FSB, nice M4 ramps, auto carrier, MPI etched into bolt, badass staking on key, so-so staking on castle nut, "F" FSB, T marked, upper, 1:7, etc. Having a price point several hundred dollars over an equivalent Colt makes no sense for it though unless you value "fit and finish" over barrel steel standards and are willing to pay a hell of a premium for it. Only the higher end FNs use the hammer forged barrels too it seems.

I don't know nearly as much about testing aluminum as I do steel--besides destructive testing how do you even check something to see if it is 7075 vs 6061?

I have seen the "6 position=6061" argument before but wonder if there is more to it.

But, the rifle being discussed here would be using the rifle RE anyway.

[seedubs1]

BCM uses 7075 for their carbine buffer tube (proof in link below). Not sure about their rifle length buffer tube, though.

http://www.bravocompanyusa.com/Milsp...milspec-re.htm

Colt uses 7075 aluminum for their rifle receiver extensions. FN is unknown but likely uses 6061 and BCM uses 6061.

So, Colt wins here.

[556Cliff]

All of the Mil-Spec 7075 RIFLE receiver extensions that I'm aware of have a dry film lube applied to the outside of the tube. All of the commercial 6061 RIFLE receiver extensions that I have seen have no dry film lube applied.

Other than that I don't know if there is any other way to tell the difference between the two.

[dsk]

Colt AR15A4+KAC M5 RAS is the route I'd go.

In a strange twist since carbines are so much more desireable though the 6920 and AR15A4 share an MSRP (999) BUT because much fewer AR15A4s are made it seems they are always listed well over vs 6920s being well under.

That bugs the hell out of me as well. The only places I've seen an AR15A4 for sale all have them marked up $300 or more above MSRP. Yet you can buy discounted 6920s all the time (except during a panic). I'd really like to get a 20" M16A2 clone but it seems nobody makes those anymore, at least not the quality brands.

[556Cliff]

BCM uses 7075 for their carbine buffer tube (proof in link below). Not sure about their rifle length buffer tube, though.

http://www.bravocompanyusa.com/Milsp...milspec-re.htm

I am aware of BCM carbine REs being made of 7075 but the description for their rifle REs doesn't say what they are made of.

This not knowing is enough for me to steer clear of BCM rifle REs until I know for sure what they are made of.