Learn from my mistake...

[J]

Don't use the ball headed allen wrenches on action screws. Just rounded out one of the action screws on one of my bolt guns.... Damnit! Talking about the ones in the following picture. They just don't have enough surface area for stubborn factory over tightened screws. Once they rounded it, even using a flat wall wrench was out of the picture. Time to sacrifice an allen wrench, and JB weld it into the rounded screw, let it set, get it off then replace the screw.

These guys:

[BuffCyclist]

Yup, any torqued down bolts avoid those like the plague.

I recently had to do something similar on a bolt rimfire gun, removed the scope base to shim it and stripped out one of those bolts. Luckily I was able to get it out with a screw extractor, but for a few minutes I was seriously freaking out.

eta: If you don't believe they are really torqued, you could try using a metric wrench just barely larger than the current stripped out hole, hammer it in and see if it gets enough bite. I've gotten that to work in the past. Although I've never heard of the JB Weld method and I'm sure that'd work better, just take longer and might not always be an option.

e-eta: Meant to say good luck, hope you get that bolt out! Stripped out bolt heads are always a moment and can take a while to rectify correctly. Post up how it turns out!

[J]

I'm hoping that some JB weld and a sacrificed straight edge allen wrench bonded in the screw will back it out. Will get some extractors or left handed bits if necessary, but with sufficient bonding time I think the JB weld will work.

[Tinelement]

Damn! You actually had some strong ones if they stripped the bolt head instead of breaking off where they next down before the ball.

[ray1970]

Damn! You actually had some strong ones if they stripped the bolt head instead of breaking off where they next down before the ball.

That's what I was thinking. I've broken plenty of the ball ends off but never screwed up a fastener in the process.

[BuffCyclist]

I have screwed some bolts up with them before. With quality tools, the dimensions are more accurate and they'll fit the bolt then the tool will shear off when too much torque is reached.

However, with cheaper tools, they might not be to proper dimensional specs and could spin in the bolt, which could strip the bolt.

Another thought is that it could have been cheaper bolts made from lower grade metals, and quality tools made from a harder steel and wambam bobs you're uncle.

[J]

Yep. These bolts are petty soft. Going to upgrade both when I get this one out.

[Irving]

Why does a rounded allen head wrench even exist?

[J]

Allows it to pivot.

[BPTactical]

Can you drive a Torx bit into it and get enough bite to back it out?