Getting the most accuracy out ar 15

[david.bergen]

I read an article in Precision shooting about building an accurate AR15.

In the article they talk about lapping the upper where the barrel extension meets. The autor did it with a special tool

from Brownells. He claimed that this makes a hugh improvement in accuracy sometimes it turns a 2 moa rifle in 0.7 moa

rifle. Anybody got experience with this technique?

Using a good trigger a free float tube and a quality barrel makes for very accurate ar15's he also states....

I am new to building AR 15 but have build some serious long range and benchrest rifles so i know the trics (action blue printing, bolt lapping,custom reamers,bedding, etc...) to make them shoot.

I start from Lothar Walther stainless blancs and have a 223 Wylde reamer. So I can lathe turn the contour I want, custom placement of the gas port , gas port size,..... I just need some dimensions and tips. Are there any dark secrets for getting the most out off an AR15, installing a barrel,tuning the gas system .if so please help me out.

I live in Europe (Belgium) and it is almost impossible to get parts, uppers, due to the export restrictions. There are some firms that are making lowers and upper( in europe) but the rest we have to build ourselves.

Thanks,

David

[Dan Sierpina]

Going from 2 MOA to .7 simply by lapping the front of the reciever?? I'd like to have seen that. Quite frankly the .7 result isn't even a great shooting AR. The barrel probably wasn't torqued right.

I've done my own barrels in the past, and with unsorted brass, no special work on lapping bolts, or barrel extensions etc, the rifle will shoot under.5MOA off of a good solid rest and bench.

Moving the postion of the gas port, longer gas tube is favored by Highpower shooters for Match Rifle division. But, they're shooting heavy bullets, that are single loaded for the most part. Standard parts do extremely well accuracy wise. A decent AR wil more often than not shoot as well as one of the better factory bolt guns, if not better.

You didn't say if you wanted the gun for 3 gun or another shooting sport.

[smokshwn]

I built a frankengun at one point that shot at least .7 moa. The components were an unamed stainless barrel (wilson, shilen who knows) a DPMS low pro upper, RRA carrier and bolt, and a generic aluminum two piece free float tube, JP gas block and an F2 comp. Parts were put together in a bench vice at work with a couple of strap wrenches and the DPMS multi tool. No torque wrenches, no lapping, no special sauce.

It shot MOA- with Wolf ammo for hell sakes. If I had ever taken the time to work up a load for it, it may have been a .5moa gun. My point is with good components (even modest components) it is pretty easy to build a very reliable and accurate AR.

[david.bergen]

The article in Precision shooting is by Steve Adelmann.(march 2009)

He states in the text :" I have yet to encounter an AR that hasn't tightened

up noticeably after truing the receiver"

He states that seating the barrel extension squarely and aligning the bore with upper receiver

gives better accuracy.

Because I have to start from zero , I thought that maybe it is a good thing to do.

I know it is absolute necessary in a benchrest rifle that everything issquare and aligned for the best accuracy , but as I stated the AR is very new for me.

I'll think I'll be very happy if I can build a 0.5 moa rifle, that wrks everytime you pull the trigger.

The rifles are going to be used for practical matches and long distance target shooting ( 400m with front and rear rest f-class style for semi auto rifles)

We need licenses for every rifle we own so e want to shoot them in as much types off competition as possible.

David

[david.bergen]

You can visit the autor's website and read the article , he has written.

www.riflemanconsulting.com then click om the Precision shooting cover.

Enjoy,

David

[kurtm]

Both yes and no. Squareing the receiver to the barrel is a VERY good thing to do, this IS NOT a lapping issue( like locking lugs), it is a trueing issue, and IF the receiver has a high spot ( very rare) it will make a big difference. As far as I know there is a tool to do this, but I just chuck the darn thing up and just kiss the end of the receiver. I have only run into 2 that have been bad. The quick and dirty way to cure ANY miss-alignment issue is the blue lock-tite the extention into the receiver and then screw it down good and tight, The blue fills in any voids bnetween extention and receiver and also stops any movement between extention and receiver, just like trueing. It is NOT lapping the extention to the receiver, that would cause all sorts of slop and would be very detrimental to accuracy. BTW the two bad receivers I have run into were Colt I like the other "Franken-builders" on this forum are very used to just screwing on a quality barrel onto a good receiver and having a 1/2 m.o.a. gun...it is a rare receiver that is bad. KurtM

[david.bergen]

I have been thinking about glas bedding the barrel extension to the receiver but am a bit worried with the heat it gets.

Good to hear loctite is good alternatif.

Kurt have you made a mandrel to chuck the receiver up in the lathe? Can you share some info on it?

Thanks

[kurtm]

Yes it is Aluminum and press fit into the receiver, no real big thing to make just measure the diameter of the upper. I use a nylon tipped set screw going into the side through the ejection port to tighten it to the mandersl which is a very tight push fir to start, then turn between centers and just LIGHTLY kiss the front of the receiver. Easier to do than to type it all out, but not as easy to do as "Blue" KurtM

[ShooterSteve]

Kurt, I thought it was very interesting to read about you kissing the receiver. My question is do you ever leave it outside for a winter Wyoming night and and kiss it in the morning?

[david.bergen]

Kurt,

Thank you for the info on the mandrel and lock tite.

Are there other accuracy secrets out there?

What about bolt lapping and trueing the bolt face or is this all a waiste off time and labour on the AR 15

David

[Dan Sierpina]

Kurt,

Thank you for the info on the mandrel and lock tite.

Are there other accuracy secrets out there?

What about bolt lapping and trueing the bolt face or is this all a waiste off time and labour on the AR 15

David

David,

I suggest that you check the parts in question out with a dial indicator, that will tell you if it's a waste of time. Personally, I think it is. Think about it, the barrel is hanging out of an aluminum tube with about a .125 wall thickness. Compared to a bolt gun, particularly the one's used for benchrest, it's amazing that an AR shoots as well as they do. A good barrel and quality components will have the largest effect.