Home VM68 Lightening the Stock VM-68 Hammer
The stock VM-68 hammer is a heavy beast. It's made out of stainless steel and weighs in at 9 oz. Lightening the hammer will increase the VM's cycle rate and, with some additional tweaking, can also allow the VM to run at a lower pressure.
Stainless steel is a very hard metal so you'll need a tough drill bit to work with it. I've had the best experience with cobalt drill bits. They're expensive but cut through stainless like butter.
When using cobalt bits you'll need to set the drill press to a very slow speed. I recommend using a cutting fluid as well. I use what ever waste oil I can round up to use as a cutting/cooling fluid. It is also very important not to rush! Go slow and take your time. Cobalt bits can easily break or chip if you're not careful.
When drilling into the hammer make sure not to drill into the surface where the sear comes in contact with the hammer. This is pretty much the entire underside of the hammer. Doing so could cause the sear to catch on one of the holes which would make the hammer cycle incorrectly or not at all.
The hammer I lightened went from 9 oz. to about 5 oz. I could have lightened it a little more but I wanted it to look some what clean and not hack out every last piece of metal I could. Doing all this lightening is very time consuming and the cobalt drill bits can be pricey. If you plan on doing this you might want to also consider buying a new aluminum hammer. Punisher's Customs, Cooper-T, and Doc's Machine either carry or can make new hammers.