ran into a weird problem yesterday.

[Lloyd Smale]

I don't know how it could affect it but the SP1 had a semi-auto bolt carrier.
Most of the carriers out there are the full-auto variety.
This shouldn't make a difference, but then who knows.

I wonder if your on to something. I looked and the bolt that came with that gun was a semi auto bolt carrier and all my other ones are full auto carriers. It went with the upper on to a different lower. Maybe ill try to put the thing back together and try that bolt in it.

[BK7saum]

Also, shooter grade SP1 Colts sell for $1000-1800. At the very least I'd put it in the safe and keep it as an investment or sell it. Way too valuable to separate it.

[MostlyLeverGuns]

I would try a drop-in trigger group, one that has trigger, hammer, disconnector all in one unit that is simply held by the pins and has set screw to secure its position. This would eliminate any possible pin/pinhole wear and even what could be tolerance stacking from long ago.

[Lloyd Smale]

well i tried the bolt that came with it. Same results. Ordered both a complete new lower and a cartridge trigger. Figure ill try the cartridge trigger in the colt lower and if it works i have another complete lower for the liberals to take away. If not ill toss the colt lower this time so far away i cant dig it back out.

[Lloyd Smale]

now im really scatching my head. I put a cheap cmc drop in trigger in it and it runs perfect. 150 rounds without a single burb. Somethings has to be out of spec somewhere with that lower that wont let mil spec triggers work right. Now ive got another lower coming i really dont need. Oh well someone will get a christmas present.