[Beren]

Well, my first for another person. A neighbor bought a Bushmaster AR-15 "as-is" at a recent gunshow. 20" HBAR barrel, A2 configuration.

He discovered that takedown pins don't stay in place when the spring and detent are both missing. Easy fix. Parts are on order.

Also, it was shortstroking badly. Turns out the carrier key was so loose it would literally rattle on the carrier.

According to the manual, you're supposed to tighten the cap screws to 35-40 inch-pounds. I don't have the proper tools to measure the amount of force. Is it critical for safe operation to have that measured exactly, or is "really hand-tight" good enough?

Also, the screws were not staked properly. According to the manual they're supposed to be staked in three places evenly spread out. These were only staked twice. Is that normal for Bushmaster, or is it a sign of an aftermarket change?

The owner may want the barrel fluted and threaded, but I'm not going to even touch that. That's what ADCO is for. :D

[Rockstar]

Beren: Don't know if $50 or so is too much for you to spend on a tool that you won't use very much, but Home Depot carries a pretty nice in/lb torque wrench for about $50. It's the "click" type, not the beam type. I've also found it handy for some of the jobs I do in maintaining my vehicles.

40 in/lbs isn't a lot of torque. If you dont want to invest in the torque wrench, just tighten the screws firmly and stake them.

[NMshooter]

Depends on how the key was staked.

The "field staking method" is 3 hits with a center punch spaced around the screw head.

From the factory should be a big V from the hydraulic staking machine.

If it was factory staked and the key came loose I would send it back and let them know politely your displeasure with the product.

With no torque wrench you want to be careful not to over torque as that could crack the bolts, don't know what "really hand tight" may be for you. If I had no choice and was in a jam really hand tight would do.

The bolts REALLY need to be staked, this is important.

Does that help?

[Beren]

That helps, guys. I appreciate the advice; some good info in those two posts. He bought the rifle used, and now that I've mucked with it, I don't know that Bushmaster would cover it under warranty. I will call them if we continue to have problems.