Lengthening barrel pin holes on Kibler SMR

[RocketMan58]

Working on my SMR kit and see that I'm supposed to oblong the barrel retaining pin holes a bit to relive stress as the barrel expands as it gets hot /cold. So my question to those with long gun building experience is, how and how much do you oblong those hole to allow for this longitudinal expansion. Jim's YouTube video shows him using a jewelers saw to complete this task but I'm not having much luck with this method. I'm thinking that maybe I should drill an additional hole offset to the rear of the existing one then connect them with the saw. .... I'm also thinking it shouldn't take more than a 1/16"" or so to accomplish the task but am not sure. Any advice/help from those in the know is greatly appreciated!

 

[wiscoaster]

No, you don't need to drill any more holes. That's overkill. Elongating the pin hole just a tad wider than the width of the jeweler's saw blade itself is sufficient. I found it was easier to use the jeweler's saw blade to elongate the holes if I just grasped the blade itself with my fingers and sawed without the saw frame. Mounting the blade in the frame and through the pin hole is a bit of a nuisance. If you have a pointed round diamond needle file you can use that to dress out the ends of the slot.

 

[RocketMan58]

Thank you Sir! BTW,, I did do a search on this topic before posting but came up MT. Then just now , I found this older thread in the list of Similar threads section below. I think I have what i need now.
Tight Groups,
Dave

 

[Hatchet-Jack]

I find using a jewelers saw like Jim does very tricky. My teacher taught me to drill a hole left and right of the pin hole so you have three then using a small jewelers file to remove the metal between and clean it up. This apparently is a pretty common way to go about it. Whatever you do don't be tempted to use a Dremel tool. That's a quick way to ruin your underlug.

 

[Hatchet-Jack]

 

[stubshaft]

That's how I've done mine for years.