4-40x5/8 full dog set screws and drill and tap?

[p5200]

I'm replacing factory trigger on a bergara bmr 22LR. Thought I would try the trigger mod lots have done. Not sure which tap to buy. Something that will be less likely to leave shavings inside the trigger. Suggestions needed on what tap, and where to order the 4-40x5/8 full dog set screws. Thanks!

 

[ironpony52]

put grease in the flutes of the tap to trap the chips. Is it a thru hole? if so a regular tap. Blind hole a bottoming tap. If you get lucky you might find a tap cut to push the chips back up instead of down into the hole, they do make both might just be hard to find.

 

[p5200]

The hole doesn't go all the way through so I guess I would need a bottom tap? I've never tapped anything before. I found the screws on ebay but, they are not 5/8" long only 3/16"

 

[ironpony52]

The hole doesn't go all the way through so I guess I would need a bottom tap? I've never tapped anything before.

Is the hole already partially tapped ?? if not you may need a starting tap and a bottoming tap to finish the threads. Also if it is a shallow hole you made need to grind the lead down on the starting tap.

 

[p5200]

No threads there is a ledge 1/4" down that sticks out maybe 1/16" around the circumference. The sear isn't much deeper.

 

[p5200]

Here is a 4-40 tap I was looking at?

 

[p5200]

Oops, I forgot to post the link. Someone knocked on the door and distracted me lol!

 

[hero's machine]

If you've never run a #4 tap before.....buy a few. They break very easily. You'll want to learn on something non critical. There's only 2 common taps that are smaller than a #4.

 

[p5200]

https://drillsandcutters.com/4-40-carbon-steel-bottoming-hand-tap/?gad_source=1&gclid=Cj0KCQjwvb-zBhCmARIsAAfUI2uu1hHsgTpbFWdYRNw9LCGmcvZeGUErygljxge1FPd2LDK82kFqojEaAmYwEALw_wcB

How about this one?

 

[RichJ]

Don’t buy Chinese taps

Rich

 

[hero's machine]

I'd run an osg myself. If it's not hard material a form tap will be nice.....if it is, you'll need a cutting tap.