Any one have any experience with Colts sporter model. Is it a 5/8" barrel. I'm wondering if it has the same barrel whip as Rugers mini-14 causing accuracy problems.

Don't even compare a Colt SP1 with a Mini-14.

I used to have a SP1 and it was my first AR back in '71.

It's pretty accurate grouping about 1 1/2 to 2 inches at 100 yds.

Every once in a while I could make a 1 inch three shot group in the standing shooting position.

I wish I could have kept it but I traded it in with a Colt Sporter 2 in the mid 80s.

My dept has several original SP1 Colts and the accuracy is superb. I wouldn't mind finding an SP1 upper and converting it over to a free-float tube and see if it gets better.

Some guys really like their Mini14s. I think their barrels are shit personally. If you can get a good deal on a used mini get one of the aftermarket barrels for them to find true happiness.

SP1 barrels GOOOOOOD!

An SP1 upper is almost EXACTLY the same as the first M16 rifles.
The POI will vary as the barrel heats up in extended firing , or if you put pressure on the
barrel.

( this is true with almost ANY rifle)

That said however , they do not "whip" when fired.

Due to the method of attachment , Barrel Harmonics with an AR15 are minimal.
( which is why adding a freefloat handguard usually makes them super accurate )

Use of 55 gr. ammo is advisable due to the 1/12 rifling twist of course.

Thanks for the info guys, I don't know how to make it hot but here's a link that seems like a good deal to me. Take notice that this price is with-out carrier group.


http://www.cdnninvestments.com/arsp1upnewco.html

Do a search for "CDNN" and you will find a few threads on the Colt M16A1 uppers offered.  I bought one and think it's awesome!  There are some really great pics of finished rifles.  JohnRippert built an absolutely kick ass one (as did many others).

Shal1