Home Forums Hunting & Shooting AR and Tactical Rifles AR parts swap outs

With a set of Go/no go guages can a average Joe change out the barrel or upper reciever on thier AR with little concern or is the a job best left to the professionals?

I've never had more than the bolt assembly off.
Spot

I don't own a set. Have rebarreled many ARs. I do check fired brass right away with a headspace brass gauge. That being said if you use good bolts and the barrel is chambered correctly OR you use a matched set you should be fine.

You'll need the correct tools too though.

My gunsmith(who is very picky about parts) says he's never seen a bolt and chamber far enough off to worry about.

E4E-- chime in.

You cannot adjust the head space on an AR barrel anyway, because the headspace is built into the barrel extension which is installed at the barrel factory. All you have to do to remove the barrel is remove the lock nut, slide in the new barrel, and retorque the nut, aligning the gas tube holes. You need a special AR wrench ($30) and a AR receiver clamp that fits into a vise. That is it in a nutshell, but you also have to remove and reinstall the gas tube from the gas block. Not a hard thing to do.

Spotshooter,

I have to agree with Rost and his 'smith with one caveat and for two reasons.

Number one is that "Murphy" lies in waiting in everything we do with any firearm, and the cost of his sick humor can be fatal.

All rifles and their components are made or assembled with Human influence.

All parts assembled are "Lot checked".

Murphy being the prankster and quite efficient at beingsneaky will ensure at least one out of X number of units, is flawed.

I dunno about you but I pretty much suck at games of chance, and have learned long ago that "luck" is the result of preperation, attention, and double verification BEFORE going forth.

Second reason is the influx of GARBAGE components and parts on the market, that is sold by second and third tier vendors and manufacturers.

The Politics of Military and other high end contracts dictates who gets what and the standards of acceptance for inclusion to the inventory of any AR maker are thus, that components for an upper will be rejected from time to time.

The rejected lots will then be sold as parts or assemblys for a discount price from the second and third tier folks.

It's like accepting the house has cut your odds and tossing the dice anyhow.

All of our Bushy M4's are headpsace inspected upon acceptance, and then after a 250 round break in, and then semi-Annually after that.

No problems so far and several million rounds downrange within our small circle.

Have been reports of a few here and there elsewhere however.

Also have had several "Mongrel" AR's put together with mix and match parts come accross the counter that did NOT Headspace except on the field gauge, and one that was so undersized, I couldn't accept it untill after several tries.

Back in 200-2002 there was dearth of barrel extensions (The locking lug "Barrel nut" that screws onto the stripped barrel.) and some folks cashed in with sub quality components.

Some are still around.

If ya can't swing the cash for the Gauges (And remember that 5.56 and .223 are different gauges!) , have a good local 'smith that is framilliar and knows his stuff check it for you.

Over a lifetime, the Gauges are the cheaper route.

Stick with Tier one suppliers that you trust.


Odds are that a slapped together upper will be fine, but there is always a winner in the Big lotto, and the odds aren't as good with the rifle, and there is no real reason to gamble in the end.


All of my seperate uppers have dedicated bolt carrier groups.

That way the two halves are a marriage.

It's a small amount to pay to know Murphy has to work harder at getting a laugh at my expense.

I extend the same to my guys at work.
So far, we have had no drama, while several others around us have had some issues, one or two of which, have been painfull.

Controll all the varibles you can.

Best of luck!
E4E

Spotshooter,

I got off track.

Apologies.

Rebarreling is no big deal ifya got the right tools, and can be a fun and rewarding to do.

Just kill any doubts.

If a dumb Grunt like me can do it, anyone that changes their own oil can do it.

The gauges are there to verify things are safe when you are done.

Dump the coin and get the gauges, or have the upper checked.

E4E

E4E,

Thanks! I'll start hanging out at the local HP club here and I'm sure I'll pick up plenty from the other shooters. I was really just wondering how far I could go when working on my soon to be own AR.

On my hunting rifles, I bed, free float, and custom load everything. I think the biggest things I'll want to do is free float my barrel, and possibly get a new flat top upper down the road.

99 out of 100 I'm going to pick up a slightly used Bushmaster target model from a friend. I'm not a serious competition shooter but want to get back into shape shooting. I'm thinking this one will work fine for me and I can also use it for some coyote hunting.

Thanks again,
Spot

Spotshooter,

Get the proper tooling, and supporting hardware, and rebarreling and such is a breeze.

Just respect the critical dimensions first.

Floating the barrelis easy if you can drive a roll pin, and have the "Feel" for turning the wrench.

Get a mag block, and a receiver fixture for the vice.
Also pick up the Military barrel wrench and a Heavy duty barrel wrench.

TheMil. Wrench comes in handy during final torque.

The Heavy duty wrench is invaluable for disassembly and initial torqueing the new barrel before final torque.

Everything you need is sold byBushmaster, and Brownells, with the local hardware supplying punches and hammers.

If you can fuss your way through a bedding job,
You're gonna love farting around with an AR.

They really are nothing more than a leggo set with a trigger.

Have at it with confidence!

It ain't that hard!

All the best!
E4E

Thanks E4E,

I might be bothering you a bit later when I get the thing in my hands.

Spot

You can also swap your upper out and I think the cost would be about 125 dollars difference. Also, as stated, buy from a reputable maker, i.e. Bushmaster, Armalite, etc for the big guys...There are some good smaller makers. We had weapons made by LMT and they are exceptional.

I'll second MontanaSteve on the LMT components.

Absolutely first rate uppers and lowers, love the back up iron sight, and have assembled enough of them now that I really like their stuff when it can be found.

E4E