Colt AR 15 SP1 Carbine

**OLIAR15** · 12-09-19, 04:18

I just bought a 1980 made Colt AR 15 SP1 carbine. I had bought an SP1 rifle last year, so I’m thrilled to have a carbine to go with it. Those are quite rare here in Switzerland. Paid $ 1600 for it.

And it has a few strange features, if anyone has infos pls chime in.

Chromed BCG

Funny looking front pin

Colt mag with a circled (1)

Vinyl acetate covered stock

The nut is staked in two places, with a dab of black paint

Paint near the bolt release lever

Full auto hammer

Sear pin and full auto selector

The pin is quite lose and falls off

M16 BCG

So what’s the story, did Colt build some full autos SP1 carbines ? Or was this transformed by a previous owner ? The auto sear is missing, and I bought this carbine as a semi auto. Could the sear be installed ? I already have two full auto rifles, an M16A1 and an XM177E2.

**Firefly** · 12-09-19, 10:07

Looks aftermarket conversion to me. IIRC a factory FA Colt would have been marked M16 or M16A1 for their export. Plus would’ve had 14.5 barrel and normal pivot pin

JMO

**militarymoron** · 12-09-19, 11:17

If it's the big hole pivot pin, that's just an aftermarket pin instead of the double screw. Is the auto sear hole anodized inside? Looks from the photo that it may have been drilled by someone. That should be a good clue as to whether it came from the factory like that. The auto sear pin needs the auto sear installed to be retained.

**OLIAR15** · 12-09-19, 14:54

And pic of both SP1 together

**ALCOAR** · 12-09-19, 16:02

Wow that makes me so jelly

That stock is just cherry. I want a SP1 carbine so bad. Let alone one that has a happy switch.

**Firefly** · 12-09-19, 16:31

You need Tiger Stripes. They make SP1 anything mehr besser.

**CAMagnussen** · 12-09-19, 16:44

Definitely something funky with the OP's AR, but ... cool.

**Firefly** · 12-09-19, 16:59

Originally Posted by CAMagnussen

Definitely something funky with the OP's AR, but ... cool.

It’s a conversion. Look at the sear hole. See the silver. It’s gonna walk no matter what. I wouldnt bother with the pin. Or get something rubber to fill in the hole but not interfere with the FCG