Ok so there are nice A1 chrome lined barrles (they might be thin but they are light) but how does the 1:12 rifling affect the overall weapon? Does it mean that you only recommend 55 gr. bullets?

Now whats so diff. about the A1 handguard besides the shape? Is it thinner? Does it break more easily? Is it more comfortable?

And is the A1 stock better thatn the A2 stock?

How about sights? How is the A1 rear diff. from the A2 rear? Which one is better?

ANd receivers: I guess the A2 receiver is much better but you never know. I am thinking of making a really light rifle. At max. 6 lb. (the AR180B doesn't have a carry handle and a cool ambidextrous charging handle)

Where can I get new A1 or A1 profile barrels? What is worth getting that is better than the A2 version?

Doggonit

if you don't like being limited on bullet weight with the 1/12 twist. Buy an A2 barrel in 1/7 or 1/9 and have it turned down to the A1 profile. Personally I like the light barrels. They do heat up fast though. check the "Parts For Sale" board or Gunbroker or Auction Arms. There's always someone selling A1 uppers and barrels. Seem nobody likes the olds 1/12 twist. The A1 rear sight isn't elevation adjustable like the A2. I don't find this a problem, I don't adjust mine that often. I just finished making two more uppers in the Early M16 style with slabside receiver and improved twist lightweight barrel and triangular handguards. Just my preference.

Why the A1 handguards? Are they more comfortabel or they just feel better to you for some reason? (magic?) So the 1:12 barrel is a hindrance?

Doggonit

I have an SP1 and i love it. I prefer the shorter A1 type stock. I also prefer the A1 style Forearm. It is flat on the bottom, letting you get a more sturdy grip on it. Triangle forearms are getting harder to find, but they seem to fit in the hand real well. the A2 grips aren't bad, but i can't get as sturdy of a grip with them.

1/12 rate of twist reportedly won't stabilize bullets heavier than 55 Grn. No problem since 55 Grn. 5.56MM NATO is available by the truck load. The plastic used to make the original triangular hand guards is different (weaker) than the newer plastic. They can and with abuse will crack, chip and break more easily than the A2's. I think they switched to round hand guards so they wouldn't have to supply a right and left hand guard. The round ones are interchangeable. I prefer the A1 style. Mainly because it's was what I was trained with. I'm more of a combat style shooter than a precision shooter anyway. The set and forget A1 sights suit my shooting style and are fine for a combat rifle. The M16A1 with 55 Grn ammo is plenty accurate for it's intended purpose. I have a like new Colt M16A1 upper on an RRA lower. It's my current favorite G.P rifle.