AR Sponsor
Posted: 1/3/2009 10:12:41 AM EDT
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Just purchased a very nice SP1 for a very reasonable sum. ( I think ).
If I had the box it came in I would probably call it LNIB or very close. It's been 30 years ago that I had an SP1 which is long gone, but still have 3 AR's and now 4. Help on I.D. Barrel has CMP Chrome Bore and no rate of twist marked on it. No shell deflecter Trapdoor in stock Model SP-1 Carry handle has C M There is very little if any wear in mag well, bolt shows very little wear, T-Handguards no wear. It's just a very clean SP1. I think it would be an A-1 ? |
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What exactly are you needing help with?
The rifle sounds like a standard Colt Sporter with a 1 in 12" twist. These are not true "A1's" in the military sense. They lack the raised fence area around the mag release button and do not have the forward bolt assist on the upper receiver. In addition to the front take down and FCG pin oversize. Still a very collectible rifle in it's original factory built form. Post pics if you can. |
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I believe he may be right. I think Colt didn't start the oversize FCG pins until the Sporter II's came out, in response to ban issues. Of course, I could be wrong. (Often am  )Later than SPII. I didn't see any until they started using the sear block in the blue label era. |
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Help on I.D. Barrel has CMP Chrome Bore and no rate of twist marked on it. No shell deflecter Trapdoor in stock Model SP-1 Carry handle has C M There is very little if any wear in mag well, bolt shows very little wear, T-Handguards no wear. It's just a very clean SP1. I think it would be an A-1 ? Sounds like every other SP1 made. As said, the SP1 is modeled more after the Model 604 (M16) rifles than the Model 603 (M16A1) rifles. AFAIK Colt never offered the SP1 with the forward assist or mag fence. They were all slab sided lowers with oversized pivot pin and standard sized hammer and trigger pins. Colt switched the fire control pins to the oversized pieces in the post ban Match Target line. About the same time they finally switched to the standard sized pivot pins.
The forward assist was added with the mid and later runs of the AR15A2 Sporter ll in the late '80s. The mag fence was introduced in the mid 90's with the later mid to later runs of the Sporter Match and Sporter Target preban guns. This is a rather vague and general timeframe and there are some indepth threads on these subjects but it is a fair, general timeframe of things. |
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Quoted:
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Help on I.D. Barrel has CMP Chrome Bore and no rate of twist marked on it. No shell deflecter Trapdoor in stock Model SP-1 Carry handle has C M There is very little if any wear in mag well, bolt shows very little wear, T-Handguards no wear. It's just a very clean SP1. I think it would be an A-1 ? Sounds like every other SP1 made. As said, the SP1 is modeled more after the Model 604 (M16) rifles than the Model 603 (M16A1) rifles. AFAIK Colt never offered the SP1 with the forward assist or mag fence. They were all slab sided lowers with oversized pivot pin and standard sized hammer and trigger pins. Colt switched the fire control pins to the oversized pieces in the post ban Match Target line. About the same time they finally switched to the standard sized pivot pins.
The forward assist was added with the mid and later runs of the AR15A2 Sporter ll in the late '80s. The mag fence was introduced in the mid 90's with the later mid to later runs of the Sporter Match and Sporter Target preban guns. This is a rather vague and general timeframe and there are some indepth threads on these subjects but it is a fair, general timeframe of things. The over sized pins began in the late 80's ealry 90's with the blue labl preban guns. |
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Help on I.D. Barrel has CMP Chrome Bore and no rate of twist marked on it. No shell deflecter Trapdoor in stock Model SP-1 Carry handle has C M There is very little if any wear in mag well, bolt shows very little wear, T-Handguards no wear. It's just a very clean SP1. I think it would be an A-1 ? Sounds like every other SP1 made. As said, the SP1 is modeled more after the Model 604 (M16) rifles than the Model 603 (M16A1) rifles. AFAIK Colt never offered the SP1 with the forward assist or mag fence. They were all slab sided lowers with oversized pivot pin and standard sized hammer and trigger pins. Colt switched the fire control pins to the oversized pieces in the post ban Match Target line. About the same time they finally switched to the standard sized pivot pins.
The forward assist was added with the mid and later runs of the AR15A2 Sporter ll in the late '80s. The mag fence was introduced in the mid 90's with the later mid to later runs of the Sporter Match and Sporter Target preban guns. This is a rather vague and general timeframe and there are some indepth threads on these subjects but it is a fair, general timeframe of things. The over sized pins began in the late 80's ealry 90's with the blue labl preban guns. You're right. I have an early preban blue label that still uses the old slabside lower with all it's features including an "SP" prefix to it's serial number and had it in mind when I typed that, forgetting it was the later preban blue labels that introduced the oversized fire control pins. Thanks for the correction. |
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Standard SP-1. Has large diameter pivot pin but all else GI sized.
Upper has no forward assist, but also does not have relief cut for auto-sear. Earliest ones have no serrations on bolt carrier, but after 1970 or so they did. FH is three prong up until late sixties then became birdcage after that became the GI spec. Likewise, after about 1969 or 70 the stock went to the A1 style with the trap door. In most regards, the SP-1 went from a 604 to a M16A1 as far as the common parts, with only a slight lag after the military changeover. |
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So if I have a slick side A-1 upper with the sear relief. I have a early M-16 upper? If the pivot pin is small, then yes. So oit won't be an A1 upper. Most probably an Air Force surp M16 upper. "A1" by definition describes an upper with forward assist. 
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