Building an AR: how doable?

[stockton]

Check this out...

http://www.brownells.com/ar15builder/ar15builder.htm

[Dan Sierpina]

Just out of curiosity I have spun a few barrels with indicators on them that had the extension 'factory' installed, and I wasn't impressed at all. I do think the next one I build I will start with a blank barrel and do it all myself.....

How pricey were the barrels? Something in the line of a Kreiger? I think the proof is how well they shoot, which is the total system....ammo in particular.

[GentlemanJim]

I've been dabbling in this a little lately. The things the average guy can't do at home that can really make a difference are squaring the upper receiver face so the barrel torques down square, and fitting of the barrel to the extension and the extension to the upper. Other than those things it is more or less a lego affair IMO given that quality parts are used.

Me too

Now I only use Lothar Walther in rifles I build for sale

JP holds a very high standard, and I have never seen an issue with ANY of his stuff.

Wilson makes nice barrels...used in Rock River and others.

In todays market many companys are cranking out less than good stuff and lots of parts are coming in from other countrys

In many ways an AR is the sum of its parts...you should stay with known quality components!

I think its great when folks jump in and learn enough to build their own stuff.

But its also true that there is a difference between a custom Built...and a put together from generic parts gun.

Or an over the counter gun for that matter.

Choose wisely take your time...and it will work out.

Jim

[VegasOPM]

I've built two and they shoot pretty good, but I'm sure that there are a lot of smiths out there that could rebuild them better.

[HSMITH]

Dan, I should mention I have somewhat of an OCD thing, in my every day full time job .0005" per 12" angular is a huge tolerance, wide open 'throw a pickle down a hall' type tolerance. I didn't see anything close in the barrels, I won't name names but one was in a 'custom order' upper with a premium barrel and premium parts. That upper was right at a thousand dollars minus sights..... The second was a 'match grade' consumer upper, the third was a rack grade rifle. The puzzling part was there wasn't enough difference to discriminate based on tolerancing of the three. The three upper receivers measured showed just over a thousandth variation in the barrel extension bore diameter, and that is not taking into account the rest of the upper tolerances. Granted, I am more or less forcibly entering this arena, I can't buy what I want so it is possible I am being more critical than necessary but being in the business of making these sorts of parts and assemblies I see no reason they can't be held to much tighter tolerances, especially the angular tolerances. My main concern is shooting 30 rounds in 15 seconds, POI should NOT change and in my early examinations of the rifle I see these dimensions as being important. More experience with the type might show different, but I doubt I will have the time, energy or finances to see how screwed up they can be and still work 'right'.

Jim, your wisdom on these things is always appreciated.

[StealthyBlagga]

I've built all mine. As long as you buy quality components from a trustworthy source, there is no reason why you cannot build a 100% reliable tack driver. It really is laughably simple with only a few, inexpensive, specialized tools being required. The most important components are the barrel and the bolt - don't skimp here and you won't go far wrong. That said, my match rifle runs an old Wilson stainless barrel and a plain vanilla GI bolt and still shoots to the full potential of the ammo. Custom gunsmiths can work wonders with some guns, but IMHO the value they can bring with the AR15 platform is very limited. Build the rifle yourself and spend the $$$ you save on practice ammo. Oh, and I'm a firm believer that practical shooters should be able to work on ALL their match guns.

Welcome to the BRD

Edited January 22, 2009 by StealthyBlagga

[Dan Sierpina]

Dan, I should mention I have somewhat of an OCD thing, in my every day full time job .0005" per 12" angular is a huge tolerance, wide open 'throw a pickle down a hall' type tolerance. I didn't see anything close in the barrels, I won't name names but one was in a 'custom order' upper with a premium barrel and premium parts. That upper was right at a thousand dollars minus sights..... The second was a 'match grade' consumer upper, the third was a rack grade rifle. The puzzling part was there wasn't enough difference to discriminate based on tolerancing of the three. The three upper receivers measured showed just over a thousandth variation in the barrel extension bore diameter, and that is not taking into account the rest of the upper tolerances. Granted, I am more or less forcibly entering this arena, I can't buy what I want so it is possible I am being more critical than necessary but being in the business of making these sorts of parts and assemblies I see no reason they can't be held to much tighter tolerances, especially the angular tolerances. My main concern is shooting 30 rounds in 15 seconds, POI should NOT change and in my early examinations of the rifle I see these dimensions as being important. More experience with the type might show different, but I doubt I will have the time, energy or finances to see how screwed up they can be and still work 'right'.

Jim, your wisdom on these things is always appreciated.

Howard,

A blind man can see you have a Type A personality

You have to remember that the majority of the parts are made by a very small number of vendors. I think if you took a bunch of barrel extensions and checked them they would have good tolerances, and realistic tolerances for the use of the part. The design of the rifle with the bolt locking into an extension rather than the reciever seems to take a lot of the variables out, that would make a bolt gun shoot like crap. To be honest, if you ever checked some of the production bolt gun recievers, you'd shake your head in amazement that they can shoot as well as they do.

Anyway, if you get a blank and machine it yourself, you'll still buy an extension, and bolt. You can lap the two together before chambering, which may or may not make a difference. Then cut the chamber to minimum headspace. You may want to try and put the gas port in between lands too, which means you'll have to put the port in first, and work backwards to get the barrel extension the right distance and in line with the port. The extension threads are fairly fine, so, the distance can be off less than one thread pitch, and everything will work. Don't forget to work on the barrel nut, so not to have to put a ton of torque on it to get the gas tube holes to line up. I almost forgot to mention bedding the recievers, so you'll need a hammer and punch to push out the takedown pin. Then after all that, you'll probably find that it still won't shoot any better than .3 at 100 yards. Yes, I've done all that, with blanks from Wilson, Douglas and K&P.

Then you have to try and load benchrest quality ammo

[HSMITH]

Thanks Dan, great info. LOL, the gas port being in the groove is one of the things that I wanted to address so I guess I am pretty obvious!! I should have some new lathe technology to use soon that will make all this a lot easier, and ease my mind....

[Dan Sierpina]

Thanks Dan, great info. LOL, the gas port being in the groove is one of the things that I wanted to address so I guess I am pretty obvious!! I should have some new lathe technology to use soon that will make all this a lot easier, and ease my mind....

Krieger is the place that mentions that. I had K&P make me some 4 groove barrels with wide grooves to try it, rather than just drill the port after the extension was on. It's difficult to say it makes a difference, because every barrel is an individual. I really haven't seen enough difference between the Wilson (Match Grade) and the other brands of barrels. They all shot well.

If you want to bed the recievers, I recommend Bisonite. That stuff is harder than woodpecker lips!

Edited January 22, 2009 by Dan Sierpina

[HSMITH]

Woodpecker lips are HARD, LOL. Thanks for the info Dan!

[Triggerbender]

I've built all mine. As long as you buy quality components from a trustworthy source, there is no reason why you cannot build a 100% reliable tack driver. It really is laughably simple with only a few, inexpensive, specialized tools being required. The most important components are the barrel and the bolt - don't skimp here and you won't go far wrong. That said, my match rifle runs an old Wilson stainless barrel and a plain vanilla GI bolt and still shoots to the full potential of the ammo. Custom gunsmiths can work wonders with some guns, but IMHO the value they can bring with the AR15 platform is very limited. Build the rifle yourself and spend the $$$ you save on practice ammo. Oh, and I'm a firm believer that practical shooters should be able to work on ALL their match guns.

Welcome to the BRD

+1

Doing the research and actually getting the parts that are the right combo for your game and style of shooting is the hard part. (Today's political situation and all isn't helping)

Buy quality proven parts.

If you are mechanically inclined at all and NOT one of those guys that use the "if it don't go force it" method you can build yourself a sub MOA rifle.

I personally find the right AMMO and trigger make the thing shoot. All my stuff can out shoot me

Go for it.

[ChrisMcCracken]

Thanks for all the input! Since this isn't a rushed deal, I'll probably do a lot of research and compare what I can make to what I can get from JP or Benny and the price differences between them. I think that last post has a very good point. I'm just not sure what parts are quality and what parts combo will make the gun that I want, and It has to be sub moa or I'll never be happy with it.

Here are my thoughts thus far: Firebird receiver, JP Trigger, Lother Walther barrel, benny comp, and a fiberglass floated handguard or rails and guards. I'm not sure how to pick the barrel specifics like length, twist, #grooves. I don't know what other choices are important, like bolk and carrier. What about how the bolt is cycled? Weren't there recent debates over gas vs piston or different venting schemes. I'd love it to be either easy to clean or not picky about how clean I keep it. Advice?

Chris

[GentlemanJim]

Dan, I should mention I have somewhat of an OCD thing, in my every day full time job .0005" per 12" angular is a huge tolerance, wide open 'throw a pickle down a hall' type tolerance. I didn't see anything close in the barrels, I won't name names but one was in a 'custom order' upper with a premium barrel and premium parts. That upper was right at a thousand dollars minus sights..... The second was a 'match grade' consumer upper, the third was a rack grade rifle. The puzzling part was there wasn't enough difference to discriminate based on tolerancing of the three. The three upper receivers measured showed just over a thousandth variation in the barrel extension bore diameter, and that is not taking into account the rest of the upper tolerances. Granted, I am more or less forcibly entering this arena, I can't buy what I want so it is possible I am being more critical than necessary but being in the business of making these sorts of parts and assemblies I see no reason they can't be held to much tighter tolerances, especially the angular tolerances. My main concern is shooting 30 rounds in 15 seconds, POI should NOT change and in my early examinations of the rifle I see these dimensions as being important. More experience with the type might show different, but I doubt I will have the time, energy or finances to see how screwed up they can be and still work 'right'.

Jim, your wisdom on these things is always appreciated.

Howard

Settle down boy

If you build it to the tolerance you suggest...and a Gnat flew by and took a dump in your rifle...it would jam it up

Jim

[Gunsby_Blazen]

i am sorta building one right now, went out and got a Smith lower, wanted to have one and it was sort of an impulse thing...

i was going to build it up getting all the components and doing it myself but just decided to buy a JP upper, well i advent done that yet but i plan on it very shortly. i figured they would probably put the upper together better than i could...

anyway, thats the route i took .. er.. am taking

[HSMITH]

Jim, I just want everything straight (or square), an extension that fits the upper correctly, the barrel fit correctly, a chamber that is straight, things like that. Seems to me that if all that were done it would shoot better than one that wasn't done as well and wouldn't wander nearly as much as it got hot. I'd let the rest rattle like every other rifle so it works LOL.

[Dan Sierpina]

Jim, I just want everything straight (or square), an extension that fits the upper correctly, the barrel fit correctly, a chamber that is straight, things like that. Seems to me that if all that were done it would shoot better than one that wasn't done as well and wouldn't wander nearly as much as it got hot. I'd let the rest rattle like every other rifle so it works LOL.

Howard, if the barrel is done by a quality supplier, it will be done correctly. If it wanders when hot, it wasn't stress relieved properly, and possibly not a real straight bore before contouring.

[HSMITH]

Thanks Dan, I haven't found out whether or not my expensive barrel set wanders yet, I only have about 20 rounds through it, but I did spin it and wasn't impressed at all. It shoots good, but we will see what it dos when it gets hot after I get enough rounds through it to be comfortable getting it hot. I put a FF tube on an entry level gun and it spun about the same, but I haven't been shooting with it since to see if it wanders.....

[Dan Sierpina]

Thanks Dan, I haven't found out whether or not my expensive barrel set wanders yet, I only have about 20 rounds through it, but I did spin it and wasn't impressed at all. It shoots good, but we will see what it dos when it gets hot after I get enough rounds through it to be comfortable getting it hot. I put a FF tube on an entry level gun and it spun about the same, but I haven't been shooting with it since to see if it wanders.....

You want to be unimpressed? Tear apart a Remington 700 and check the barrel and action

[sheik_djibouti]

isn't "flawlessly-functioning competition gun" an oxymoron?

i've seen more competition rifles sh*t the bed than stock guns. just throw everything together and see if it runs. as long as everything fits and there are no major defects in the various parts, it'll all come down to gas function and positive extraction, and you can adjust those variables from home unless you need to resize a gas port or polish/ream a chamber. ar's are dirty animals, so i'd recommend getting the right cleaning tools like the sinclair barrel extension cleaner. when i clean my rifles, tools like that help me get them spotless. however, i typically clean them once every 2k+ rounds ... i am about as bad as it gets with rifle hygiene. as long as you keep adding good lube, they'll keep going bang until the sludge becomes too much to overcome. good luck with the build- you'll have fun!