I mentioned this in another post, the idea anyway of starting a thread dealing with retro or even pseudo-retro rifle accuracy. The notion is: What does it take to make a more accurate rifle using the AR15/M16 A1 (or retro) platform. I was going to say 1 MOA, but that may discourage reasonable efforts as it is a pretty high bar to set. The goal is to get great accuracy from a retro rifle with retro, retro inspired or even retro looking parts.

Criteria would include any rifle that would have, could have existed using the AR platform, and parts available back in the day. So it might look exactly like an issued XM16E1, but not limited to that only. Might look like a prototype with a somewhat heavier barrel, or a 656, or an 18" barreled XM and, you get the idea.

More builders are beginning to use aftermarket parts in their builds, particularly the light profile barrels that are available. Been wondering how these would stack up for accuracy. Other parts that could contribute to a better shooting experience like trigger groups, iron or glass sights, reworking the action etc.

Ammo is always a factor, but would be interested in seeing what others have done, or could see doing with retro or repro hardware first and foremost.
Just looking for ideas, and wondering if anyone else has done the same.

One thing I noticed on a Colt SP-1 upper I have is that the receiver face is perfectly true when I checked it with a lapping tool.

I would also take a Dutch Armalite up against most of the $3000+ AR10's nowadays for accuracy.  Whatever they did, they are amazingly accurate in my experience.

I need to shoot my 605 for accuracy.  It even ate some 75gr BTHP's my friend had, and was hitting steel with them.  It ate XM193F just fine, without needing to open the gas port.

My BIL made a 1st-round hit with my 727 build at 400yds from a standing position.

You can carefully work your trigger and hammer connection in these old guns to achieve a really great feeling trigger.  Polish the trigger nose without removing material or changing the geometry (angle) of it, and carefully polish the hammer notch.  You can also drop in a JP AR10 hammer spring to reduce the pull weight, and install the JP reduced power disconnector spring.

Use the magazine as a monopod so that there is consistent handguard to barrel interface, and find a load that works well in your existing guns.

Back in the day, the 70's or thereabouts, the Navy [edited to say, might have been the Air Force instead) did some experimenting with building match rifles [not service rifle configuration] for NRA across-the-course competition. They whacked off the carry handle for installation of Redfield International sights, installed a globe front sight on a heavy barrel and used some kind of tubular handguard to free float the barrel.  

Nowadays "space guns" like that are relatively common in match rifle competition, using flat top upper receivers and Warner or other similar rear sights, but back then it was pretty innovative, even radical.  The American Rifleman had a write up on all this at the time.  From what I recall of the article, the rifles were quite accurate, but the rub was that heavy bullets were not available back then, so they were severely disadvantaged at long range, and not practical for the intended purpose.  The military teams have generally been more interested in service rifle shooting anyway, so it was an evolutionary dead end back then.

I did a quick web search on the subject, nothing came up within the short parameters of my attention span.

Someone here posted a pic of an upper kind of like you describe, Andouille. One of the retro long timers. Had a peep site and HBAR if I recall. Will try to locate.

Thanks for your responses so far. Good stuff.

this one?

http://www.ar15.com/forums/t_3_123/478134_retro_target_upper.html

i have a stripped upper without the rear sight parts.

Yup, that's it.  I'd forgotten about that thread, even after having posted in it.  One of the pages from TBR indicates Rock Island Arsenal, which obviously would be Army, not Navy or Air Force, my mistake.

same with their Garands, they shoot lights out

M16A1s were modified with semi triggers and some other tweaks for competition at Camp Perry, among other service rifle competitions. The information has got to be out there. Check out the other thread with coldblue's rifle I recently posted in. FWIW, the Marine Corps has always been a driving force in rifle competitions - at least since WWI. I really like the ALG ACT trigger, and I really believe that's one reason my 605 is so damn accurate. My friend commented that it was a laser - I think it has less barrel whip as well. I think a standard, USGI A2 barrel would make a very good starting point.

yankee-V: I'm glad you brought this subject up. Monday I will be taking my newly pieced together XM16E1 replica to the range for the first time. The barrel is brand new and un-lined. 6 groove RH 1-12 twist like original E1. Manufacture unknown. The upper M16A1parts kit is all Colt (like new). Lower is NDS-XM16E1 and a very tight fit to upper. I've done a little reading up on breaking in a new barrel for better accuracy. For once I will take my time and go a little over board on the first 45 shots following strict cleaning instruction guidelines. This rifle is not precision by any means, or maybe it is? I'll find out and post early next week. I expect decent accuracy if I follow the rules of breaking in this new barrel.

http://s29.photobucket.com/user/bwagss/library/XM16E1

I had looked at some of the trigger options and would like to settle on one baseline rifle to build with accuracy options in mind. Heavier barrel (A2 maybe), trigger group, good sights, and a nice tight lock between upper and lower.

I have an SP-1 with a RRA adjustable trigger in it. It shoots about like you expect an AR to. Maybe 3-4 inch groups at 100 on a good day. I won't go into all the details of the last visit to the range with that rifle, but my results were wide ranging. As LRRP said, match the ammo to the rifle and build on that, I may back up and go from there.

Wags, Sounds like you have a great break-in plan. Let us know how it goes with details. Wonder if you can find out the make of the barrel.

All I know is that I purchased this barrel from Sarco when I attained the Colt M16A1 kit. Sarco stated it was from a major USA barrel manufacture? It was in the white and non drilled when it arrived with the kit for an extra $125. Hopefully someone has an idea who the manufacture is.

never mind, not germane

I have put Geissele triggers in all my ARs including the retros.  All of my retros will shoot as accurately as I can make them per the ammo I am using.  With good reloaded ammo I can get 2-3 inch groups with iron sights and 1-2 inch groups with the Colt scopes. Add an inch to those spreads without the Geissele triggers.

"You expect more from Amoco Geissele, and you get it"

A Geissele trigger will not make your rifle more accurate.  But, it will help you find the accuracy inherent in your rifle.