A GWOT Throwback: The Cat’s Mfg M4A1 Build

Most of my military clone builds focus on fixed carry handle models from the M16A2 backwards. Partially because I like the vibe, and partially because the A2 was the “latest”  rifle I was issued when I was in the service. Yeah, I know, I’m old. I do have a couple newer builds though and recently had a chance to put together an M4A1 using an matched upper and lower from Cat’s Mfg. Although even the M4 is over 30 years old now.

Cat’s Mfg?

Who the heck is Cat’s Mfg. you might ask? Cat’s is a subdivision of Bad Attitude Department, whose receiver’s I’ve used on a bunch of my builds. The Cat’s lowers amuse me with their rearing cat logo, and I  wanted to do a build with one. When I saw that they were releasing an upper and lower set with a vintage, worn finish I jumped on it. The set was $199.95 .

The lowers have M16 cut pockets and comes with the pivot and takedown pins already installed. The take down pin has a captive spring which is a really nice touch. The markings are ” PROPERTY OF U.S. GOVT, M4A1 CARBINE, CAL. 5.56MM” and the serial number. Plus the rearing cat logo of course. It looks like a military issue marking until you close and catch that it’s a cat, not a horse.

The Vintage finish is meant to replicate a gray from the 70’s to early 90’s that’s been well loved. They’re artificially aged and colors can range from a washed out grey to a bronze/copper color. While these come as a a set, just like with actual issue guns, the upper and lower aren’t necessarily going to be a perfect match. My upper and lower show similar levels of wear but the upper is noticeably darker. Unless you’ve got a high level of OCD this is appropriate for a well used issue carbine.

The Rest of the Build

With upper and lower in hand I needed to finish off the rest of my build. I had a surplus detachable carry handle that also had some wear to it, so that was a perfect fit for my upper. I picked up a bunch of my other parts from B. Kings in Ohio. B. Kings is a veteran owned business and they deal in a lot of retro parts. I’ve been getting a good bit of stuff from them over the past year or so.

I ordered one of their 14.5 inch chrome lined M4 barrels with a pinned and welded extended A2 flash hider. I didn’t want to bother SBR’ing this for the inch and a half it would have been under 16 inches. SBR rules are stupid. If you order a barrel from B. King they have a pin and weld service available that’s very reasonable. I’ve done this a couple times now, and it saves me a good bit on sending a barrel out locally to have a pin and weld done later.

While I was ordering my barrel I also picked up a lower parts kit, a two position carbine buffer tube in their silver/gray finish, a buffer spring and buffer, forward assist, a quad rail, and a B5 CAR stock. To round out the build I used a gray charging handle from H&R, a phosphate BCG from KAK Industry, and a shiny LS2 grip from B5 Systems. The ejection port cover was from Wilson Combat.

I also ended up swapping out the selector lever with a KAK 3 position semi automatic model. Normally  these are just for fun. The three positions end up being safe, semi, and semi. Paired up with a drop in Kabuto style FRT unit though they allow you to have safe, semi, and FRT. I have a couple FRT units I’ve started working so I’ve dropped these selectors in a few of my builds.

GWOT Build

I’m pretty happy with how this one came out. It’s a nice representation of an earlier GWOT build and my only quad rail set up other than my M16A4 clone. The combo of vintage Cat’s upper and lower, surplus carry handle, and B. King buffer tube give it a nice vintage look. Like anyone knows who’s every carried an M4 variant it’s a pretty handle build. I still need to add a sling and decide what, if anything else, I’ll throw on there. I plan on running it for a while first and maybe checking out some GWOT pics before I decide.