Pulling my Cavalry Arms Plastic Lower out of the Closet

Pulling my Cavalry Arms Plastic Lower out of the Closet

While I wait for my Palmetto State Armory AR15 lower receiver I thought I might share something I have sitting in the safe.

Cavalry Arms MKIIIt’s is a Cavalry Arms (now Cavalry Manufacturing) lower receiver.There are many AR15 lower receivers on the market but one quick glance will tell you why this one is different. It can be considered the first successful iteration of the “plastic” AR15 lower receiver. Bushmaster’s Carbon 15 series never really gained much steam and other plastic lowers on the market are often looked at with the hairy eyeball… but the Cavalry lower came out swinging and showed the community just how durable a plastic receiver can be. 

Despite its current pedigree over all other brands of plastic lowers I really
don’t really know what to think of it yet. If you look closely you can see it is molded in two pieces and then welded together.
Cav Arms claimed 75,000 rounds had been put through one of their demo
models in an ad I saw online. That is pretty impressive for a “new”
technology. The piece is solid, fairly attractive, and can be ordered
in a variety (rainbow like even) of colors.

One of the problems I encountered with this
lower was how much hand fitting was required when installing certain components. One particular component was the buffer detente. When I inserted
the buffer detente into the pre-drilled hole it pressed in with a
friction fit and it wouldn’t come back out. It was one of those moments
when I wanted to choke myself for not checking and looking for excess
flashing.  I had to remove the detente with need nose pliers and then
drill into the hole to remove the excess plastic.

Furthermore the

magwell did not permit the magazines to drop free. Some file time was
necessary here to lower the high points on the inside of the mag well.
Nothing too difficult. 

Cavalry Arms

The buttstock trap door assembly was a
plasticy rubberized piece of flimsy worthlessness that I didn’t want on
my rifle. I had to replace it with a A2 trapdoor assembly. The stock
flimsy trap door assembly feels as though it would bulge or break and
release the contents of my buttstock to the floor.

One more problem I noted is that the loose molding of the bolt hold open recess allows the catch to tilt back and forth. Such a tilt allows the bolt catch to miss the follower as in the photo below.

This occurred while manually cycling the weapon. The bolt chewed into the follower rather than stop via the bolt hold open. I will have to shim this to correct the issue.

Cavalry Arms

I don’t
really have a use for this lower at the moment. It has various features
that would suite the needs of my 20 inch rifle build, such as A1 stock
length and the fact that it is ultra light weight… but I think I will  
reserve it for a secondary rifle project in the future if I can get comfortable with its performance. 

Eugene Stoner’s original M16 design weighed around 6.3 lbs. Today’s M16A4 weighs 7.4 lbs.

What happened here?

This Cavalry lower is screaming for a M16A1 upper with pencil barrel.

Do I smell a side project?

Written by lothaen

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