In 1993 I bought a Colt Sporter Lightweight R6530. This was Colt's AR-15A2 carbine with an A2 stock instead of the correct collapsible, a permanently installed sear block in the receiver, and no evil bayonet lug. Oh, and .170" pins for the hammer and trigger, instead of the correct .155" pins, to prevent installation of FA FCG part. The bolt carrier was cut to work with the sear block and it had an unshrouded firing pin (which meant that when the rifle cycled, the hammer was being cocked by bearing directly against the firing pin, instead of the bolt carrier. Nice )

After the 1994 Crime Bill, which included the Assault Weapons Ban, Colt was able to sell only neutered, ridiculous rifles to non-LEO, non-military- no collapsible stocks, no flash hiders, and no evil bayonet lug. Yeah, that'll fix our problems.

They were, however, able to sell complete uppers and "spare" barrel assemblies.

Remember the old U.S. Calvary company? I used to get their catalog on a regular basis, and in 1996 or 1997, they started advertising Colt conversion uppers, and in 1997, I bought one- specifically the AR6721DC. This was the upper for the then recently-introduce AR-15A3- what we know today as the Model 6721. Flat top, 16" HBAR twisted 1:9, flash hider, and the evil bayonet lug.

Even though I did intend to utilize its nifty flat top, I still had the presence of mind to buy removable Colt carry handle. The upper and the carry handle, having been made in 1997, were finished in the old Colt grey finish. I mated the upper to my Sporter Lightweight, purchased out of Shotgun News a kit consisting of a Colt N1 collapsible stock, correct Colt receiver extension, Colt buffer (standard weight) and spring. I put a Checkmate Industries rubber buttpad on the stock and added a Giles Sling (remember those)?

Here it is in 2006 wearing an AAC 18T and way too much scope- a US Optics SN4 Mark I.



Not exactly a practical setup. Shortly thereafter, I realized I could use a proper BCG on the sear-bocked lower, as long as the carrier was semi-auto. I bought the best I could find for it- a Lewis Machine & Tool LM7A1. Shrouded firing pin, of course. Works like a charm.

Because of this, I put the old Sporter Lightweight upper back on the lower and now have what is essentially an AR-15A2 Carbine, except with no evil bayonet lug. Damn handy rifle, and even though the fire control group has oversized pins, the trigger pull- unlike what came on later Colt ARs, is actually quite good and needs no improvement.

I sold the US Optics scope, never really warmed up to it, so the 6721 ended up on a standard AR lower and with an Aimpoint red dot sight. It shot fine, but damn if it didn't look odd, with a grey upper and a black lower.

Around 2017/2018, I got to thinking about buying a Nodak lower, since you could get them in a finish intended to match the old Colt grey. Beyond the matching color, this turned out to be a great purchase, because the machining of these Nodak lowers was second to none. Of all the AR lowers I've purchased, the Nodak is the best. I installed an ALG ACT trigger and the then-new Magpul UBR second generation stock. This is a heavier than average collapsible stock which counters somewhat the heavy 6721 barrel, and one of the great things about it is that it is made to accept Vltor A5 buffers. The idea of the A5 system is rifle-length action spring/buffer performance. Explained in detail here, at the bottom of the page.

I have three ARs set up with the A5 system. The other two are mid-length gas systems, which have the correct cork time, so in those two rifles I use what is considered the standard A5 buffer, which VLTOR calls the A2. This is a 5.33 ounce buffer. The 6721 upper can be considered to be overgassed and the cork time is longer, so in my 6721, I use what VLTOR calls the H3 buffer, which is 6.08 ounces. The A5 system uses a rifle-length action spring.

The rifle now uses an Azimuth BCG.

This a really smooth and solid set-up, and with the fixed cheekpiece of the UBR, heavy 6721 barrel, the smooth VLTOR A5 system, this is a big rifle in a smaller package, and I just love it. And it looks great, too. Surefire M300 on an IWC mount, and a custom Blue Force Gear VCAS, with the color scheme reversed (black adjustment tab instead of grey, and grey sling instead of black). A few years back, I switched out the AAC 18T to a 51T for my AAC M4-2008 suppressor.

I’ve always wanted to try an UBR stock but they seem so heavy. I love cast off Colt uppers. They used to be easy to get and reasonably cheap.

That UBR looks to be the newer version or perhaps the lightweight one? I have an original in Foliage Green on my first AR build, an SPR setup.

I recently got a Reptilia stock which is a similar design albeit simpler in execution (no storage compartment). It seems like a nice piece of kit.

I'm a fan of the 6721 setup...I've got one that was a surplus LE gun, Diemaco-made in Canada that got for a song.

That looks like a pretty solid rifle, I kinda want a basic 6721.

Ah, the good 'ol days of the 94 AWB.
I never got into auto loaders and such during that time and just stuck with what I had.
I did buy a .22 cal Marlin, 7 shot mag with a stupid mag block for larger ones.
A small notch in the Butler Creek like the 7 round had and I was in business. Still have that one.

When the ban lifted I jumped straight to rebuilding FAL's.
The first one cost me $275 not counting tooling, milsurp ammo was everywhere for dirt cheap.
Of course they had to suck the fun right out of that.
.308 was a lot more fun to shoot when it was $25 for a 400 round can.

Got into AR's next cause yanno, cheap ammo.
Fun sucking bastards..

I like the A5 a lot more than a regular carbine buffer and spring, though I did just pull one off of my 18" for an A2 stock.

BCM has an A5 kit now also.
A few years ago it was nearly impossible to get just an A5H2 buffer.
I had a .308 extension with hardware and a rifle spring.
I wound up having to buy a Vltor Emod A5 stock kit just to get that damn buffer.
Only one left was forest green, dicked around to long and the black ones went poof.
By the time I was putting another together the A5H2 buffer was available again so that worked out.

Nice setup, very KISS. I hadn't thought about U.S. Cavalry for years! I, too used to get their catalog in the mail.

Looks good, Para. I like a simple setup, and that one has everything you need and nothing you don't.

quote:

Originally posted by PGT:
That UBR looks to be the newer version or perhaps the lightweight one? I have an original in Foliage Green on my first AR build, an SPR setup.

I recently got a Reptilia stock which is a similar design albeit simpler in execution (no storage compartment). It seems like a nice piece of kit.

Yeah, that's the Gen 2. I have a Gen 1 and eventually took it off my rifle to cut weight. I was toying with the idea of picking up a Gen 2, but like you, I snagged a Reptilia. It's almost exactly half the weight of the Gen 1. I haven't put it on anything yet, but I have it set aside for a lightweight DMR type build I'm doing. I like everything about my UBR except the weight, so I'm looking forward to getting this one together with the Reptilia.

quote:

Originally posted by powermad:
A few years ago it was nearly impossible to get just an A5H2 buffer.

Yes, VLTOR seems to be a relatively small company and I had to be diligent when collecting up A5 parts. In addition to what's already installed in my three A5s, I have spare H2, H3 and H4 buffers. The H4 is for supressed use on this rifle.

The Emod stock, I have on one of my other A5 rifles. It's a very nice stock but it's fairy heavy.

quote:

The bolt carrier was cut to work with the sear block and it had an unshrouded firing pin (which meant that when the rifle cycled, the hammer was being cocked by bearing directly against the firing pin, instead of the bolt carrier. Nice )

! Very cool rifle, Para, I like the simplicity of your final setup. Thanks for sharing the design background. I got into guns just a couple of years after the sunset of the AWB, so I (gratefully) never experienced stuff like that. Do you by chance still have that carrier lying around? I'd love to see a photo of it, and the sear-block in the lower receiver. The mechanical hoops that designers would jump through to comply with (or circumvent) onerous regulation has always been interesting to me, be it guns, automotive, or really anything else mechanical.

Some interesting history there. Takes me back.

I dig the gray and the whole scheme going on with that rifle. I'm fairly ignorant about the A5 system but have only heard good things about it. VLTOR in general always seemed like a solid company.

If I could go back 1 thing I'd take care of would be getting more of the Colt rifles like that A2 Carbine and try to have an example of all of them. Took it for granted back then. I never imagined Colt would go the way they went and someday when I get rich I may be overpaying for rifles I could have had for nothing.

In terms of close-range shooting and home defense, there is an advantage of the A2 rear sight which is not apparent.

Sight in your rifle for a 50/200 yard zero by adjusting the front sight post and with the rear sight elevation wheel all the way at the bottom of its range (which is how it's intended to be set for zeroing).

Normally, when you shoot an AR up-close, say, twenty feet, your bullets will strike several inches low. Well, if you're keeping your rifle for home defense use and it has an A2 rear sight, you can compensate for this very easily. Just elevate the rear sight as far as it will go, and at 20 feet, using the 0-200m large aperture, your bullets will strike about one inch below point of aim.

Going outside and taking shots at distance? Then, just return the rear sight to its lowest position.