GunTalk-Online.com

Just joined! Great info. here. Thanks to all who who make this board so informative.
I bought a MK III 22/45 recently and hated the trigger, so I lightly stoned the sear, polished all inner parts, and took the lump off the trigger as per info on wiz-tech site. When the gun is racked,and the safety is placed on safe, if the trigger is touched with the gun in this condition, when the safety is moved to fire, the gun fires a round. Not cool!!
I have worked on other guns with good results (including a 10/22).Any ideas would be great.
Thanks Carl

Welcome to Guntalk-Online!

Your pistol's condition is known as a bump fire. It is caused when the firing components geometry is changed and the designed dimensions are exceeded. In this case, the hammer and sear are now engaging, or can be pushed past the point of release. When the thumb safety is engaged, a hook covers the sear face so the sear cannot travel any further forward to release the hammer hook. But if the sear face can travel far enough to go past the hook's release point, when the safety hook is removed (or unswitched) the hammer is directly released by this action, causing the hammer to fall. This is what has happened to your pistol. Either by wear of the firing components or by removing too much material in the polishing process, the firing components are now beyond specifications for safe operation. If you only polished the sear then you will only need to replace the sear. But if you also stoned the hammer hook then you may have to replace it too. Fortunately a new VQ sear is relatively inexpensive.

Chalk this one up to "Do not free hand polish the hammer or sear components in a Ruger 22 Auto." I caution against this technique all the time. It takes special jigs and stones to ensure the hammer and sear engagement angles are kept intact when working on these pistols. Once the angles are exceeded the only remedy is to get new parts and start over.

Hope this helps.

R,
Bullseye

Thanks Bulls Eye. What I thought but did not want to hear and you are right I read more than one caution on this. I am lucky I found it and no one got hurt.
I guess I just believe that if you don't try you don't learn. Got to really check after I do work on a gun to make sure it is safe.
I take it that the material I took off the trigger has no bearing on the problem? Thanks again the internet gun sites have let me learn much.
Carl

Taking the hook or horn off of the backside of the trigger is just a way to smooth up the back of the trigger to a Mark II configuration. This has no impact on your problem. The sear and hammer engagement is the problem. You found it by using a step in final testing to see if you have a safe pistol. I use this step all the time in final checking a pistol. And if the pistol fails, I too have to start again. The objective is to have a safe reliable pistol.

R,
Bullseye

Fixed it! Installed Voquartsen sear. Good to go, Thanks again.
Carl

Good to hear that you've got it solved. That's a good fix for the price of a VQ sear.

Enjoy your pistol.

R,
Bullseye