Gunsmithing Newbie AR question

[Bighouse]

I helped a buddy out and swapped his A2 upper for an A3. The A3 was stripped and I swapped his parts from the A2. This is the most I have ever tinkered with an AR's upper. My question is should I assume the new upper will work or should the headspace be checked?
The rifle is all together and appears to be in working order.

Thanks for any advice.

 

[monteboy84]

Re: Newbie AR question

The upper has nothing to do with headspace, don't worry a bit.

-matt

 

[Victor Co Heather]

Re: Newbie AR question

Don't worry about it- you're good to go.

 

[salmonaxe]

Re: Newbie AR question

Pulling a barrel from an AR and putting into a new upper is pretty much the most complicated thing you could do on an AR. (Which isn't saying much, since it's super simple to do.)

I am curious, if you hadn't ever done anything like this, did you buy an armorers wrench for the barrel nut?

 

[Bighouse]

Re: Newbie AR question

Yes I bought a multi tool. Thanks for chiming in guys. I just dont know much about them and would rather be safe than sorry. Thanks again.

 

[AXEMAN]

Re: Newbie AR question

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: monteboy84</div><div class="ubbcode-body">The upper has nothing to do with headspace, don't worry a bit.

-matt </div></div>

im no expert, but if you swap uppers then you remove and remount the barrel. wouldnt you HAVE to check the head space? ive built lowers, never touched uppers so im not positive.

 

[salmonaxe]

Re: Newbie AR question

Headspace on an AR is controlled by the barrel extension. Barrel extensions are fixed to the barrel and pinned in place. (Also the index pin.) If the person who made the barrel is competent, and you have a quality bolt, it should headspace correctly. If the bolt and barrel came together, then head space should definitely should be good to go. If bolt and barrel come from 2 places, it's good to check with a field gauge.

I like to buy a new bolt for barrels that I didn't get a bolt with. Usually direct from the people who made the barrel.

 

[scotharr]

Re: Newbie AR question

It's the bolt and barrel extension fit that determine headspace. If the bolt and barrel stay matched, then nothing has changed with headspace.

 

[AXEMAN]

Re: Newbie AR question

ahhh, thanks for that. never done anything with the upper but buy one.