Drilling Gas Ports

[Cosby]

OK guys, I want to drill out the ports on my 1100CM but I do not have any letter drills. Can anyone advise the corresponding sizes, ie. 3/32, 7/64 etc.? Or is it as simple as checking my bit sizes with a micrometer?

[EricW]

You can't do the job right without a set of letter drills and slowly working your way up in increments. Either get a set of letter drills or find a gunsmith who does. Try to remove too much metal at once and you're just going to end up with a mell of a hess and be $200 poorer.

[Round_Gun_Shooter]

Here is every drill you will ever need

http://www.northerntool.com/webapp/wcs/sto...uctId=473&R=473

[SGDM]

.125 or 1/8" drill bit. This is the recommended size for the gas ports, no larger.

[Cosby]

Thanks guys! I ordered the drill bit set from Northern Tool. Looks like a helluva deal. May all your reloads be lightning fast.

[warpspeed]

Cosby,

What you want to do is find the drill that just goes on the existing port hole. Start out small and use them like a pin guage to find the size. Once you identify the biggest drill that will fit, take the next size up and drill out the gas ports. Reassemble the gun and try it. Without knowing the reason for opening the ports, I'd say don't go more than 2 sizes up from where the factory set them. Drill slow and let the existing holes guide the bit.