Want to build sm AR that looks like an early M16 carbine: A1 stock, triangular carbine hand grips etc. I have a SP1 slick sided upper but have some concerns...the forward assist was put on the M16 to help seat the bolt if dirty or dinged cartridges did not allow for full seating. I believe I read this was added after early rifles were having issues with the ammunition powder leaving a residue in humid asian countries. Should I look for another upper with a forward assist or should I be ok? I see alot of builds with the SP1 configuration so I could use some help here..Thanks in advance!

Sam

PS- this site is AWESOME for information to parts!! Thanks again!

Do what Osprey said - look in the retro forum.  Retroblackrifle.com is a good source, too.

Don't worry about the forward assist.  Modern day ammunition will be fine.  The majority of my rifles are slick side.  On the ones that have a forward assist it is not used.  Some people swear by them - just in case.  Some people think they are worthless.  I can't recall ever using a forward assist.  In most cases, especially in non combat situations, solving a problem with the forward assist is not the best answer.  Finding out why the problem exists and fixing it is the better way.

EDIT:  You may be mixing up terms.  There were very few carbines with triangle handguards.  The 607 is the only one I can think of off the top of my head.  There are plenty of rifles that had triangle handguards.  For ease of explanation a carbine M16/AR15 style gun usually refers the length of the gas system.  Here is a retro style carbine and a couple retro style rifles - and all three are slicksides:

 

Great info guys! I knew you wouldn't let me down...What I want to do is take one of the advertised "light" barrels (aka pencil type) of 16 inches I've seen advertised and put a set of triangular handguards from a model 607 on it. I'm not too sure if it is dimensionally feasable length wise so I will continue thru the retro forum to see if anyone has done this. Also from the sites I've looked at there seems to be a triangular endcap on the back part of the handguards of the 607, will have to look into that too. Thanks again for your help! AR15.com is AWESOME!!!!!

Sam