quote:

Originally posted by Alberta Canuck:

1. When one buys a barrel for an AR-10, are the barrel and barrel extension one solid piece? NO

Or, does the barrel screw into/out of the extension? YES

2. Is the same true for an M-16/AR-15? YES

3. If the barrels screw into/out of the barrel extensions, why would a minor variation in extension length make any difference in the functioning of the rifle?

The tenon length/depth of the extension lugs controls the distance between the bolt lug faces and the breech face.

Wouldn't that simply be a matter of threading the barrel to a proper length to seat properly in the extension one already has?

Pretty much, .620"

4. If one is fitting ANY make of barrel to ANY Mattel design rifle, wouldn't he always measure the important dimensions of the parts being installed, and fit them to his desired specs?

I do, it still takes me less time to do an AR barrel than a typical bolt action rifle.

I know I sure do that on all other kinds of rifles, because I have found that manufacturers' dimensions & tolerances are often, at best, only approximately correct, but not always exactly so.

The barrel extensions I've used from DPMS have all been within .0015 of each other.

5. I got the impression, perhaps incorrectly, from what I've read here about it, that fitting a barrel to a Mattel rifle seems to be taken more as a job of "assembling" pre-dimesioned more or less drop-in parts, rather than hand-fitting them. Is that correct, or not?

If you've already got the barrel assembly headspaced, extension pin set, gas port drilled - you can pretty much just bolt it together.


AC