Posted: 9/1/2005 9:08:57 PM EST
If you are not already equipped to remove the barrel, then you have come to a decision point in your AR life's path.
Do you want to invest in tools and tinker yourself, or do you want to pay someone else (maybe no charge if DPMS does it) to do the work.
To remove a barrel, you mostly need a barrel nut wrench.
If we are talking about the DPMS 308 rifle, then I recommend this one:
It works with both DPMS and AR-10.
For one simple tear-down and rebuild, you can probably forego all the other nice tools that would be used for this job.
Do you have a gas block or front sight on your rifle?
In either case, start by removing that.
Gas blocks attach with setscrews from the bottom.
Front sights are usually held on with tapered pins.
Make sure that you hammer on the SMALL end to remove them.
Once you get the gas system clear, you should be able to remove the handguard tube from the barrel nut.
It's a two-piece arrangement that simply threads together.
A strap wrench may be helpful here.
As for holding the rifle, I recommend a padded chair without any arm rests.
Sit on the whole rifle (leave the lower and upper assembled at this point) and let your body weight be the clamp.
With the gas system and handguard tube now removed, remove the barrel nut with your newly aquired barrel nut wrench.
Place rifle on chair, muzzle to the right and sit down.
Insert the wrench into the barrel nut facing forward, away from your body.
Pull UP on the wrench to break the nut loose and then spin it all the way off.
That's all there is to it.
You will need to withdraw the bolt carrier group at least an inch to let the barrel pull free from the upper receiver.
When you put it back together, it's important that the barrel nut is aligned to the same place it came off.
This is to say that the hole (in the barrel nut) for the gas tube needs to be centered over the hole in the upper receiver so that the gas tube goes straight into the center of the receiver.
All other re-assembly is basically the reverse of removal.